Leo Fitz

"You make things from the genius of your mind and the goodness of your heart to help people."

- Jemma Simmons to Leo Fitz

Leopold James "Leo" Fitz was a Scottish-born former S.H.I.E.L.D. agent and scientist. A genius engineer, he is one of the youngest and most prominent members of S.H.I.E.L.D.'s Sci-Tech division, and inseparable from his research partner and friend (and later wife), Jemma Simmons. He, along with Simmons, was recruited to Coulson's Team and worked with them on all of their missions. While on the team, Fitz became good friends with teammates Grant Ward and Skye. During the HYDRA Uprising, Fitz was an active participant in hunting for John Garrett and the rest of the Centipede Project. He was shocked by the revelation that Ward had been a member of HYDRA all along, and refused to believe it. When Ward was ordered to kill him and Simmons, they were trapped on the ocean floor. They escaped, but Fitz spent a long period of time without oxygen, causing brain damage.

As time progressed, Fitz's condition seemed to get better with help and support from his fellow S.H.I.E.L.D. colleagues rebuilding it. Slowly regaining his skills, Fitz was able to get back into doing active field and lab work, and played an important role in the conflicts with Robert Gonzales' S.H.I.E.L.D. faction and during the War against the Inhumans, in which he caused the death of teleporter Gordon. However, soon after the war was over, Simmons was swallowed by the Monolith and disappeared.

Fitz studied the Monolith for months and with S.H.I.E.L.D.'s help, he went through a portal to a distant planet and rescued her. Although Simmons returned, Fitz was devastated to learn she had met and bonded with the astronaut Will Daniels. Fitz helped Simmons research a way back to the planet, but their work attracted the attention of HYDRA, which forced Fitz go back to the planet to bring their Inhuman leader home. There, Fitz learned that Daniels had died and his body was possessed by the dark Inhuman. Fitz destroyed Daniels' body and returned home, believing the Inhuman was dead. However, the dark Inhuman, Hive, managed to return to Earth. Fitz and Simmons, having become a couple meantime, tried to find a cure to Hive's power of controlling Inhumans' minds. S.H.I.E.L.D. eventually managed to kill Hive.

S.H.I.E.L.D. had its new Director appointed by the president after the signing of the Sokovia Accords. Fitz worked with Dr. Holden Radcliffe on developing an Artificial Intelligence called Aida which was designed to serve S.H.I.E.L.D. as a decoy target. He was caught in an explosion with Coulson and Ghost Rider by Eli Morrow and was almost sent into another dimension, but managed to get out. Fitz then helped S.H.I.E.L.D. in their last fight against Morrow. To Fitz's shock, Radcliffe betrayed S.H.I.E.L.D. and used Fitz's technology against S.H.I.E.L.D.. Fitz was captured and his mind was connected to the virtual reality called the Framework where he lived a rewritten life as The Doctor, Aida's lover and HYDRA's ruthless second-in-command. After he created for Aida a machine to become a real person, Fitz left the Framework, traumatized from his behavior there. But when Aida learned Fitz didn't love her back, she planned her revenge on him. S.H.I.E.L.D. eventually succeeded in defeating her. Shortly after, everyone in the team but Fitz were taken by mysterious people.

Fitz was then arrested by the army and taken to a black site prison. However, former S.H.I.E.L.D. agent Lance Hunter rescued him and brought him to Enoch, the one who took the team. Fitz decided to go into suspended animation for 74 years to facilitate his rescue of the team. Once in the future, Fitz took up the identity of Boshtok the wealthy Marauder. He managed to break Simmons and Daisy Johnson free from Kasius' enslavement, getting engaged with Simmons in the process. After the team managed to return to the present, however, due to multiple stressful factors, Fitz also experienced a psychic split which enabled his dark personality from the Framework to resurface at times. They continued working on a way to prevent the Destruction of Earth, came into a conflict with General Hale's HYDRA and later with the Confederacy. In their final battle against Glenn Talbot they succeeded to change the course of history, however Fitz was killed in the process.

Raised by Mother
"He walked out on them when Fitz was 10. He hasn't seen or heard from him since."

- Jemma Simmons

Leopold Fitz was born in Scotland, United Kingdom on Wednesday, August 19, 1987. A genius-level engineer, whose only other relative is his mother, after his father, Alistair Fitz, left him at age 10.

Meeting Simmons
Leo Fitz started attending the S.H.I.E.L.D. Academy of Science and Technology in 2004, where he met who would become his equally intelligent best friend, bio-chem expert Jemma Simmons. Among their instructors at the academy were Professor Vaughn and chemical kinetics advisor, Professor Franklin Hall.

Graduation
"You said, and I quote "Oh, Fitz, it's the most perfect opportunity for us to see the world! We'd be fools to pass this one up!""

- Leo Fitz to Jemma Simmons

Fitz and Jemma Simmons graduated from the Academy three years early, and Fitz would have been happy to spend all of his time in a lab. However, at the urging of Simmons, and against the advice of Professor Vaughn, the pair put in for a field position.

Coulson's Team
"I said there would come a moment when we would regret the decision to go in the field. I didn't think that would happen in week one."

- Leo Fitz to Jemma Simmons

Fitz and Simmons were recruited by Agent Phil Coulson to be the science crew for a new team he was putting together. Stationed on the Bus, the pair have designed specialized equipment and compounds on the fly in emergency situations.

Their first foray into the field involved the case of Michael Peterson, a man in danger of exploding due to his use of the volatile Centipede Serum. Peterson was saved in part by Fitz's invention, the Night-Night Gun, which contained specially designed bullets that delivered a Centipede counter-agent to Peterson.

Fitz first faced danger in the field in Peru, where the team was investigating an 0-8-4. Facing Peruvian rebels and an armed takeover of the Bus, Fitz found it hard to concentrate at first, but later came through for the team, using his D.W.A.R.F.s to activate the old HYDRA weapon in order to regain control of the Bus. The team received a call that a S.H.I.E.L.D. truck was attacked. They arrived to investigate, and it was discovered that a mysterious new element was distorting gravity and throwing the vehicles in the air. The team learned that the cargo in the truck was in fact Fitz' and Simmons' former professor Franklin Hall, who had been captured by Ian Quinn. Coulson, Ward, and Skye infiltrated the billionaire's home in an attempt to rescue Hall, but despite Fitz' and Simmons' attempts to convince Coulson that Hall was a good man, Coulson was forced to kill Hall when he tried to destroy the entire island and kill every person on it. Their next mission had them investigating mysterious dead bodies which floated in the air. As a team they discovered that the cause was an virus passed along from a Chitauri Helmet. On the way back on the Bus, it was discovered that Simmons was infected and would be killed in a matter of hours unless they found a cure. Fitz risked contamination and death in order to help save his friend and they successfully found a cure.

However Simmons, not realizing the cure worked, chose to jump from the plane to save the rest of the crew. Fitz took the cure and prepared to jump out after her, but instead Grant Ward jumped and saved her life. Later, they sat together and Simmons expressed her gratitude to her friend.

Operation: Overkill
"I am every bit the S.H.I.E.L.D. agent you are!"

- Leo Fitz to Grant Ward

Sometime later, Fitz and Agent Grant Ward were assigned by Agent Victoria Hand to infiltrate the border of South Ossetia and destroy an enemy weapon known as the "Overkill Device". Despite his inexperience (and a few missteps), Fitz showed quick thinking, ingenuity and courage during the assignment and was essential to the successful completion of the mission.

Agent Fitz' noteworthy actions include the timely activation of a Localized EMP Device when his and Agent Ward's lives were in jeopardy, gaining the trust of the locals (specifically Marta and Vladimi) and the modification of the Overkill Device's core, which allowed him to neutralize the enemy soldiers weapons.

Among his missteps were the vastly overpaying the locals for safe transit across the border and bringing a sandwich (prosciutto and buffalo mozzarella with a hint of pesto aioli) into the field while being tracked by dogs.

The Berserker Staff
In Trillemarka National Park, Fitz assisted Simmons in creating a 3D model of the recently discovered fragment of the Berserker Staff. Simmons scanned the imprint of the staff in the tree where it was previously embedded, while Fitz worked to create a replica back in the lab.

After Grant Ward came into contact with the Berserker Staff, he became unnaturally aggressive toward his teammates, with Fitz being one of them. Ward delivered a harsh rebuttal to the suggestion of sedation by mocking Fitz, reminding Fitz that he had been the one to save Simmons after she contracted the Chitauri Virus. Fitz seemingly ignored the comment.

Later, in a church in Oslo, Elliot Randolph was brutally stabbed with a fragment of the staff. While Simmons realized she couldn't help save his Asgardian life, Fitz supported her by reminding Coulson that she didn't understand Randolph's anatomy. After Simmons saved Randolph with the help of Coulson, Fitz comforted her when she was disappointed in herself for not being brave enough. Relenting in his comfort, Simmons spoke with her parents on the phone, a task she had been procrastinating.

Hunting a Ghost
Fitz and Jemma Simmons traveled to the StatiCorp company to gather information concerning the tragic accident that had occurred there. While on the job, the two reminisced on being victims of freshman pranks back at the S.H.I.E.L.D. Academy. Realizing Skye was a "freshman" to S.H.I.E.L.D., they decided to "give her the full S.H.I.E.L.D. experience". This commenced to a series of pranks they planned to pull on Skye. Later, Coulson's Team took possession of Hannah Hutchins, the young woman being held responsible for the accident. As Fitz entered a closet for prank supplies and couplings, he was mysteriously locked inside and the plane lost power and went down, courtesy of Tobias Ford. Fitz soon escaped the closet and met up with the rest of the team, and went to repair the damage that had been done to the plane's wiring system. He successfully got them up and running again.

Late that night, Fitz had been sleeping peacefully while Coulson, Ward, Skye, and Simmons played "Upwords" in the lounge. He silently entered the room, with shaving cream smeared across his face. He became irritated as the team laughed at his misfortune, and he demanded to know who was responsible, completely unaware of Melinda May's guilt in the prank.

Coulson's Capture
"Bet there aren't any flowered dresses where she's going." "Amen to that, sister."

- jemma Simmons and Leo Fitz

Fitz watched helplessly with the rest of the team as Phil Coulson was captured by Raina and the Centipede Project. He and Simmons had created a tech-free method of tracking Mike Peterson, but never thought to do the same for Coulson.

Once the team had returned to the Bus, Fitz witnessed Victoria Hand kick Skye off the plane. In any and all assistance he could provide, he and Simmons hid supplies for Skye in a paper lunch sack, including a SAT phone for her to reach them. In the lab, Fitz designed a new weapon using Night-Night Gun technology, which he called the Night-Night Bracelet. The bracelet later proved to be impractical in a fight. Later, in the desert where Coulson was being tortured by Edison Po, Fitz fought alongside his team to find Coulson and keep each other safe. They managed to get Coulson out, and they all reached the Bus; not unscathed, but alive. Fitz shared a warm moment with Coulson, a sign of appreciation for rescuing him.

Bad Seeds
Coulson's Team received a report of a mysterious attack at the S.H.I.E.L.D. Academy of Science and Technology. The incident involved an indoor pool instantly being frozen, with young cadets in it. The team made a visit, and Leo Fitz and Jemma Simmons, being very well known in the academy, prepared a speech to share their experiences in the field with the students. However, in the middle of their speech, a student began to cry in panic, as his body was being slowly frozen over. Fitz and Simmons rushed to the cadet, with Grant Ward and Skye alongside them. Simmons administered a drug to keep the boy alive, and Ward located a machine that was the source of the ice. Upon Fitz's orders, the machine was smashed, and the student, later revealed to be Donnie Gill, was saved. Gill briefly thanked Fitz and Simmons for saving him, and apologized for ruining their speech. He was then escorted back to his dorm to recover.

On Ward's suggestion, Fitz visited Gill in his dorm, and the two instantly connected. Fitz admired Gill's inventions and designs and he shared stories of himself at the academy and how he did not like it there at first either. He and Gill bonded over common experiences. Eventually, Fitz took note of a power problem Gill was having. He suggested to him a solution and Gill immediately realized his problem was solved.

Fitz bid goodbye to Gill and began to head to the Boiler Room of the Academy at Simmons' request. Simmons told him distressing news over the phone, that everything was not as it seemed, and Fitz rushed back to Gill's dorm. There, he discovered an upscale version of the freezing device found earlier, and frantically warned Gill of the danger. Since Fitz had seen too much, Seth Dormer, a friend of Gill's, shot the engineer unconscious. Fitz was removed from the situation, and received news that Gill's weather machine had gone haywire, causing a massive storm. The team located the source, along with Gill and Dormer, and brought them on board the Bus, seeing as Dormer was injured. He had been struck by lightning, and despite Simmons' efforts, he did not survive. Fitz tried to comfort the grieving Gill, but was pushed away.

The Chase
Fitz was captured in France and taken to Antarctica. The team rescued him and destroyed the outpost that held him.

The Italian Mission
Fitz was forced out of his niche and into field work when the team got separated during a mission in Italy where they were chasing a Cybertek Prosthetic Leg bought by Ian Quinn. He and Skye were the only ones left who could continue the chase. As Fitz waited for the others after he sent a tracking beacon, Skye went inside Quinn's mansion and was shot twice in the stomach.

Fitz blamed himself for this as the team went to S.H.I.E.L.D. Trauma Zentrum in Switzerland, and learned that Skye's wounds were fatal. Phil Coulson refused to accept this diagnosis and gave him and Jemma Simmons Level 10 access to files on his resurrection. Fitz figured out the location of the Guest House and went with Coulson, Grant Ward and John Garrett to find GH.325. After a successful Raid of the Guest House, Fitz took the serum to Skye for Simmons to inject her with it, fully healing his teammate.

Secrets
"You really are quite clever."

- Sif to Leo Fitz

Unfortunately, that was the only sample he retrieved and Jemma Simmons berated him for it because the Guest House was destroyed. He and Simmons continuously monitored Skye and took blood samples in hopes of duplicating the miracle drug, but the Bus did not have equipment sufficient enough for the job. Also, Phil Coulson ordered the research must stay in house. Meanwhile, Lorelei and Grant Ward hijacked the Bus and enthralled Fitz, who was freed of the Asgardian's control when Lady Sif eventually managed to recapture Lorelei. After that, Simmons began to look at him differently.

Fitz witnessed as Skye became an official S.H.I.E.L.D. agent and watched as Ward killed Thomas Nash. He became upset though as Simmons was called to the Hub to be a consultant on Deathlok. So they could communicate secretly about her findings on GH.325, Fitz put in a secret phone line. However, he found that Melinda May already had one. He told Skye about this just as it was realized that the Clairvoyant was a S.H.I.E.L.D. agent. May chased Fitz hoping to shoot him with an I.C.E.R. before he could reveal her secret, but he locked himself away before she found him. While Phil Coulson, May, Skye, and Fitz had a four-way argument about secrets, Victoria Hand redirected the Bus to kill Coulson's Team.

HYDRA Uprising
"You're going to suffer for what you've done. And I- I plan to be a very big part of that."

- Leo Fitz to John Garrett

Fitz watched Phil Coulson and John Garrett battle the S.H.I.E.L.D. UAVs chasing Garrett as it became assumed that Victoria Hand was the Clairvoyant. When they reached the Hub, Fitz's invention, the Mouse Hole, kept them from being captured. Garrett accidentally revealed he was the Clairvoyant and an agent of HYDRA, greatly upsetting Fitz for his betrayal. Garrett offered Fitz a place in HYDRA while Fitz swore vengeance. During the Battle at the Hub, Fitz hid but his contributions saved his teammates' lives when it was needed.

Fitz began to notice the attraction Jemma Simmons had for Antoine Triplett, but he distrusted him since he worked under Garrett. When the team and Triplett left the Hub to go to Providence, Fitz talked with Simmons, but she let him know that things have changed.

Fitz went with Phil Coulson, Triplett and Simmons to Portland to apprehend Blackout. He discovered Coulson's past relationship with Audrey Nathan, and talked Coulson into using her as bait to stop the Fridge escapee. Fitz modified the stage lights of the building using the Gamma Power Reserve designed by Bruce Banner causing Blackout to explode. When the group returned to Providence, they found the Bus and half the team gone.

Betrayed
"Ward look at me, Ward just turn around. I know that you care about us Ward!" "You're right, I do, it's a weakness."

- Leo Fitz and Grant Ward

Fitz helped Coulson research their whereabouts, but he questioned Coulson's leadership after their experiences in Portland. Looking for a skillet to help Simmons make pancakes, Fitz found a message left by Skye, "Ward is HYDRA," just as Simmons found Agent Eric Koenig's body. When Simmons' autopsy report proved Ward was the killer, Fitz had a tantrum that had to be calmed by Coulson. Meanwhile, Maria Hill led Colonel Glenn Talbot to Providence, causing Fitz and the team to relocate to Los Angeles. During this time, he refused to believe that Ward was evil, claiming that he did not think that people were born evil. He even suggested the possibility that Ward was like Deathlok and was forced to do what he did, but his teammates dismissed the idea. Eventually, Coulson's Team found John Garrett and Grant Ward in Havana, Cuba. Fitz and Simmons were able to locate the Bus, and Coulson ordered them to leave the area immediately. As they were about to, Fitz and Simmons decided to plant a tracking device on the Bus. Just then, Ward found the two as Centipede Project prepared to leave for New Mexico. He brought Fitz and Simmons aboard the Bus where Fitz activated an EMP Joy Buzzer that critically injured Garrett. Fitz begged Ward to let Garrett die, telling him that he did not have to follow Garrett. Garrett then told Ward to kill Fitz and Simmons. As they were being escorted away by guards, Fitz and Simmons managed to escape their guards, but Ward found them, resulting in a chase. Cornered, Fitz and Simmons then locked themselves into a Medical Pod. Ward demanded that the two come out, but they refused. Fitz reminded Ward of their friendship and told Ward that he knew that Ward still cared about his team. Ward finally admitted that he still did, but he called it "a weakness" and ejected the pod off the bus into the Atlantic Ocean.

Best Friends Forever
"Why would you make me do this? You're my best friend in the world!" "You're more than that, Jemma."

- Jemma Simmons and Leo Fitz

Now trapped with Simmons on the seabed 90 feet down, Fitz jury-rigged a beacon transmitting a distress signal on an unmonitored S.H.I.E.L.D. frequency, all with a broken arm. When Simmons woke up, he explained the situation to her: there was no way out of the container, and they were going to die.

However, some time later, Simmons devised a way to break the glass keeping out the water. With some hope of escape, the pair worked out the problem further. Eventually, with the detonation ready to go, Fitz handed Simmons a one-time use air supply and explained that there wouldn't be enough for the both of them. After a tearful display of affection from Simmons, Fitz hit the trigger for the explosion. Not willing to give up her closest friend, Simmons dragged Fitz with her to the surface where they were rescued by the timely arrival of Nick Fury, responding to their makeshift distress signal. While Simmons was placed in a Hyperbaric Chamber to recover from the pressure sickness, Fitz was examined by a medical team. His brain went without oxygen for an extended period of time, although his heart was still beating.

Fitz ultimately survived the ordeal. However, when asked about him later, the fully recovered Simmons would only say "he's alive" with no further context, implying that Fitz suffered brain damage from oxygen deprivation.

Brain Damage
"What's the word again? Gimme the word."

- Leo Fitz

It took nine days for Fitz to awaken from his coma, but months later Fitz still experienced damage to parts of his brain that still had not healed. The brain injury made it difficult for Fitz to complete tasks that used to come easy to him and gave him, which made communicating to other members of the team much more difficult for him. Jemma Simmons left Fitz and the rest of the team to go undercover within HYDRA for S.H.I.E.L.D. After Simmons had left, he started to imagine she was still with him and had conversations with his hallucination of her. Eventually, Fitz realized that Simmons had left but continued to have the hallucinations.

Phil Coulson tasked him with building cloaking technology for the Bus so that he and his agents could travel unimpeded by Glenn Talbot and the United States government. Ultimately, Coulson sent Melinda May, Antoine Triplett, and Skye to steal a Quinjet when he deemed that Fitz was incapable of the job. However, Fitz was able to recognize the designs he had previously done on the Overkill Device as a way to disrupt Carl Creel's powers and cause him to overload. With the help of Alphonso Mackenzie, who took his time to help Fitz explain his thoughts, he was able to modify it in order to stop Creel, who was turned to stone and arrested. This cooperation started a friendship and strong trust between the two as Mackenzie was the only person who was really able to listen and took the time to speak to Fitz.

Meeting Ward
"I - I have trouble with words, so it might be best I show you." "Show me what?" "Hypoxia, that's what you did to me."

- Fitz and Grant Ward

Phil Coulson had a meeting with the field agents, included Leo Fitz, after he spoke with Jemma Simmons, who was undercover, infiltrating HYDRA. Fitz knew Donnie Gill from the mission at the S.H.I.E.L.D. Academy and Coulson sought his input. Fitz became upset that he was not leaving for Morocco with the others. He went to the Vault D and discovered that it held Grant Ward, who was happy to see Fitz again. Ward attempted to convince Fitz that he did not want to kill Fitz and Simmons, so he instead ejected their pod into the ocean to give them "a fighting chance" at survival. Fitz then revealed to Ward how brain damaged he was and that he now felt useless to his team, who he revealed were now in Morocco to look for Donnie Gill. Fitz slowly lowered the oxygen level of the cell to show Ward what he experienced. Suffocating, Ward told Fitz of how HYDRA brainwashed some of its members, including Gill, who had taken over the Sandbox while brainwashed. Fitz, with extreme difficulty due to his aphasia, was able to communicate this knowledge to Mack, and the two informed Coulson about this. When Coulson asked how Fitz knew this, Fitz admitted that Ward told him.

Coulson met with Fitz privately after this incident and expressed his regrets that he still had Ward at the base. Fitz asked if Coulson was hiding any other secrets from him, to which Coulson replied that as director of S.H.I.E.L.D., there were a lot of things that he was not telling Fitz, but he added that this was not just to Fitz. He also let Fitz know that Simmons left S.H.I.E.L.D. upon Coulson's request.

Bonding with the Others
"Fitz, this team wouldn't be here if it weren't for you. This is big. Let me buy you a beer, mate."

- Lance Hunter

The S.H.I.E.L.D. agents took the Bus to Florida because Phil Coulson wanted a painting that had the Words of Creation inscribed on its back. While the others were bonding, discussing past relationships and love interests, Fitz was hesitant because he felt that the others did not want to be around him since he had trouble speaking. His hallucination of Jemma Simmons kept trying to encourage him, but he refused. He also believed that the others talked to Ward more than they did to him, feeling that the others found Ward more useful.

Agent 33, disguised as Melinda May, entered the Bus and planted a virus which disrupted the electrical systems. Fitz warned the others that if the virus continued the plane would explode. He and Lance Hunter went to a section of the plane that was not yet affected. Fitz explained that he needed Hunter's hands, since his were not steady, to halt the cascading effect. Together, they rewired the section and stopped the virus.

Later, Hunter brought some alcohol to celebrate a successful mission. After prodding from Hunter, who wanted to thank Fitz for saving their lives, Fitz decided to participate and began talking about a girl, without saying that it was Simmons, not returning his feelings and leaving him. Alphonso Mackenzie and Hunter said he was better off without her and toasted to "moving on."

Soon after, Fitz let go of the imaginary Jemma, when the real Jemma Simmons returned from her undercover mission. Fitz greeted her with hesitancy.

Reunion with Simmons
"I'm trying not to treat you any differently than..." "I know, but I am different. And I... And I'm... I'm trying not to be, but I am. And if for some reason you can't accept it..." "Oh, that's not fair. Fitz, I'm only trying to help." "You left. I needed help. I needed help with the cloaking. I needed help with... Um... With lots of other things, and someone to talk through, at least. You gave up on me."

- Jemma Simmons and Leo Fitz

Fitz and Simmons discussed the specifics of the HYDRA Splinter Bombs as well as Fitz's situation which led to a brief argument between them. Mack then came to discuss the specifics with Fitz which led to the discovery that Vincent Beckers, the grandfather of the Belgian Foreign Minister, was in fact a HYDRA agent in the 1940s who developed the weapon. Fitz later had a brief amiable conversation with Simmons. When Mackenzie and Simmons spoke of Fitz's predicament, he pointed to her as the cause of his trouble to which she cited as the reason why she had left.

Mental Back-Up
"Brains never delete files. They just lose connections. But there's always a backup. Just a matter of digging and finding them." "So, you've got backup files, too?"

- Leo Fitz and Alphonso Mackenzie

Fitz went with Alphonso Mackenzie and they retrieved the body of Janice Robbins so Jemma Simmons could perform an autopsy. She disagreed with the words of bravado that Mackenzie told Fitz. Fitz and Mackenzie were told by Skye to come to the secret room containing the Theta Brain-Wave Frequency Machine; their strength might be needed in case Phil Coulson acted erratically during or after the session. As predicted, Coulson had to be held down after the session ended.

As Mackenzie and Fitz played video games, because, according to Mackenzie, playing helped Fitz's brain. Mackenzie complained about how Coulson's brain was erased. Fitz explained that memories cannot truly be erased, as the brain makes back-up files that Coulson was accessing. During their conversation, Simmons entered and showed them Skye locked in Vault D.

Later, Fitz was among the senior agents that were assembled as Director Coulson gave the new mission: find the city that matched the Words of Creation before HYDRA can.

Muscle Memory
"Fitz, how you coming with the transceiver patch?" "I've got it down to 7 minutes, 20 seconds." "That's not good enough." "No, that's with my bad hand. With both, I can do it, definitely."

- Phil Coulson and Leo Fitz

Wanting to return to field work, Fitz accompanied Skye and Antoine Triplett when Director Coulson took them to Hawaii. Coulson ordered Fitz to practice on the Bus rebuilding a transceiver repetitively until he can do it under six minutes. Fitz admitted that he had only one fully functional hand. Coulson told him to rely on muscle memory.

When the Bus got to Laura Creek, Australia, Coulson took Fitz and Triplett with him to infiltrate a laboratory that housed a powerful satellite receiving station. Fitz's job was to install the transceiver so that the city matching the Words of Creation could be found. Fitz admitted that he was able to do the job in under seven and half minutes, not six, when using one hand. He then revealed that with both his hands, he would be able to do the job within the time limit, signifying his progress. The team entered the station. There they were attacked by HYDRA and Triplett got shot.

Calvin Zabo helped Triplett but used that firefight as a way to meet Coulson. As he fled, Coulson and Fitz gave Triplett the blood clotting agents needed to stop him from bleeding to death. Before they could tell Skye about meeting her father, a match was found.

Relinquishing Leadership
When he returned to the Playground, Fitz saw Mack driving a radio-controlled miniature version of Lola through the halls. Fitz, wondering if the toy could fly, asked Mack to talk to Jemma Simmons for him. Mack told him that he needed to confront her sooner or later. Fitz was chosen to accompany Phil Coulson to Puerto Rico to destroy the city that matched the Words of Creation. The team also included Bobbi Morse, Mack, and Simmons. Upon arrival, the silence between the two scientists caused Mack to leave them alone so they could talk. As Simmons tearfully tried to tell Fitz why she left and went undercover months ago, Fitz interrupted her by saying that he could not work with her anymore. She misinterpreted his statement and asked if he was quitting S.H.I.E.L.D. He told her that he thought it best for him to work for her, making her leader of the science team.

Inside Castillo San Cristóbal, Fitz and Simmons prepared the D.W.A.R.F.s to test the structural integrity of the city, so when it was destroyed, it would not affect the residents of San Juan. When the drones lost power after entering a hundred foot shaft, Mack went down to investigate. Hearing his screams, the others hoisted him up and watched as he slapped Coulson across the room. Fitz gave Coulson an I.C.E.R. to stop the attack of the super-strong mechanic, but it was ineffective. Fitz, holding a gun, pleaded with his friend to stop his assault, while Coulson, attempting to keep Simmons from falling into the shaft, ordered him to fire. He did not because Morse electrocuted Mackenzie and he fell stunned into the shaft.

Kree City
Fitz and Simmons brainstormed on how to save Alphonso Mackenzie and destroy the city when they entered the Bus. Together, they decided that the city was like a living organism that co-opted Mack to have him defend it and that hazmat suits would keep the city from detecting their presence.

Antoine Triplett was partnered with them to destroy the city with the four mechanical bombs he had. Inside the Kree City, Fitz decided that for expediency, they needed to separate to set the charges. After the charges were set, Fitz witnessed as Triplett reported to Melinda May that their task was complete. Triplett immediately returned to the city to defuse the bombs when they learned that Skye and Phil Coulson entered.

As Fitz waited with Simmons, an earthquake occurred; this caused them to hug in panic as the island shook.

Empathy
"You're just different now and there's nothing wrong with that."

- Leo Fitz

Upon return from Kree City, the senior agents dealt with the experiences differently. Fitz helped Alphonso Mackenzie with his work. Soon, Fitz found work for himself; he decided to repair and analyze Skye's heart monitor to get a biological replay of what happened to her. While working, Fitz asked Mackenzie to share his feeling about his experiences as a thrall of the Kree City. Mack shouted at Fitz, claiming that he could not understand the feeling of having his body betray him. Fitz calmly stated that he could due to his own brain damage.

Later, Fitz approached Skye in her quarantine. He began questioning the data he learned from the heart monitor, which he called "inhuman", as well as how she was unaffected by the earthquake. When he realized that she was the epicenter, Skye panicked and caused the overhead lamp to explode. Fitz ran away quickly. Fitz returned when Melinda May and Jemma Simmons saw Skye cut and bleeding. As Skye was about to admit that she was changed, Fitz interrupted her and showed the women Skye's blood test; he had changed the results to have it show that Skye was normal. When the women left, Fitz cleaned Skye's wound, explaining that until everyone has calmed down from their traumatic experiences, especially Simmons, who wanted to destroy all things alien, it was best to keep her secret between them. Skye cried and hugged Fitz. He told her that there was nothing wrong with being different.

Fitz attended the vigil the senior agents had for Antoine Triplett.

Secrets Exposed
"Can you blame me, the way you were going on about Raina, that she's a-a-a plague to be eradicated?" "Skye is my friend! She's different." "Oh, yeah. Like I was your friend, and then I changed. How did you handle that?" "Uh, t-the point is, secrets don't help any of us."

- Leo Fitz and Jemma Simmons

While continuing the search for Raina, S.H.I.E.L.D. took notice of Lady Sif, who had appeared in Portugal with no recollection of her past or why she was on Earth. They discovered that Sif had fought an unknown man who wiped her memory with a hammer-like device. Following a confrontation with the man, Skye began to fear more that control over her abilities was wavering. She confided in Fitz, thinking that telling Phil Coulson about her new ability would be best; Fitz revealed that he was talking to hallucinations of Jemma Simmons for months. When Skye stared at Fitz, he told her that that feeling would be how the others would treat her. He then attempted to ease her mind, though they were interrupted by Lance Hunter.

Upon locating the man, who was revealed to be a Kree by the name of Vin-Tak, and bringing him in for questioning, the Kree restored Sif's memory and explained that he had come to Earth after being alerted to Raina's activation of a Diviner. Fitz and Jemma Simmons opened a crate Vin-Tak unearthed that supposedly had more Diviners; during which Fitz had inadvertently left his test results of Skye's blood out for Simmons to see. He attempted to explain that they were just fake results he created; however, Simmons was not completely convinced. Meanwhile, Vin-Tak explained the purpose of the Diviners, and the Kree's role in the creation of the Inhumans. Realizing that she was in fact one of these people, Skye began to panic and lost control of her powers, exposing them to her friends. Both Sif and Vin-Tak were ready to strike down Skye in order to stop her supposed threat, but Fitz, having overheard, was quick to come to Skye's defense, furious at their suggestion of murdering her. Both Coulson and May defended Skye as well and attempted to get her to safety. Coulson told Fitz to get "Bambino." While running, he came across Alphonso Mackenzie and Bobbi Morse, and urged them to help stop the Kree. Mack, and later Hunter, were quickly defeated; but Morse managed to keep Vin-Tak busy enough for Fitz to locate the Destroyer Armor Prototype Gun. The blast stunned Vin-Tak long enough for Morse to erase his memory with his own weapon.

Later, Fitz somewhat apologized to Simmons for not telling the truth, though, at the same time, he defended his choice, due to his belief that the others would have turned against Skye. The others, furious that he lied to them, essentially proved to him that his fears were correct, with Mackenzie stating they needed to be kept safe from Skye. Skye overheard the exchange, but would not stop to talk when Fitz chased after her; instead she retreated to the Bus.

Admiration
"You know, it could be just growing pains from your new powers." "That's alright, Fitz; you don't have to put a positive spin on this." "I'm not doing that. I would never patronize you."

- Leo Fitz and Skye

As Melinda May trained Skye, Fitz interrupted the session to check on her well-being. May became frustrated with his presence; so when he asked if it was worthwhile, May challenged Fitz to spar with her. Skye politely asked him to leave since she was doing well.

Jemma Simmons continued to give Fitz the silent treatment, telling Bobbi Morse that he violated the almost sacred respect they had for science by making false test results for Skye. She further explained that she was even more hurt that their relationship had deteriorated to the point where he lied to her.

When Andrew Garner arrived to give Skye a psychological assessment, Fitz learned that he was May's ex-husband.

Sometime later, Fitz wanted to microwave some food; when he went to the kitchen area of the Playground, he saw May laughing and smiling with Garner. He chose not to interrupt and traveled to where Simmons was working to heat his food. He told Simmons why he was there and how May was acting. This sparked a friendly conversation between them, speculating on Garner's and May's relationship.

Jemma Simmons checked Skye's casts; Fitz listened as Skye complained about how she internalized her power to show she had control. Fitz told Skye that he admired her for having a power, sparking an argument between Simmons and himself as they compared her to the Hulk and Captain America, respectively. The Bus started to shake; the two both apologized to Skye for arguing around and about her.

Fitz started spending a lot of time with Skye talking to her; so much so, Skye commented on it to Phil Coulson when he took her from active duty.

When he realized that Skye was gone, Fitz asked Simmons what she gave Coulson and how it was related to Skye. Simmons said that her efforts were for helping Skye's change. Fitz argued that Simmons was the one who had changed because she became closed-minded.

Feeling Betrayed Again
Fitz sarcastically asked Jemma Simmons how her science experiment was going after she communicated with Skye at the Retreat. Fitz was asked by Phil Coulson to determine what the extra mechanism was that Alphonso Mackenzie had within the toy replica of Lola that Coulson had kept in his office.

During the blackout caused from Bobbi Morse's EMP, Fitz was found by Melinda May. The two found Coulson and all compared notes; Morse stole the Toolbox and Mackenzie was on the run. Fitz told Coulson that Mackenzie had to be found as he went to secure the Playground.

Inside a maintenance closet, Fitz found a strange gadget. As he was investigating, he was approached by Mackenzie. Mackenzie told Fitz that he was not there to hurt him and would never do so, but he wanted Fitz to leave that closet. Fitz managed to grab a weapon to defend himself. However, he did not realize that Mackenzie was trying to protect Fitz from the gadget. Mackenzie quickly grabbed Fitz and fell upon him as the gadget exploded, allowing agents loyal to Robert Gonzales to enter.

As Gonzales agents stormed the base, Fitz and Simmons silently reconciled with each other, held hands, and tried to comfort one another when Anne Weaver approached Simmons to help to diagnose Mackenzie's wounds. Simmons did not comply until Fitz approved.

Non-Compliance
"There are no prisoners here, we are all S.H.I.E.L.D. Agents. Exit protocols have not changed." "Once you're cleared and debriefed you're free to go if that's what you really want." "Okay, I'll start packing my things."

- Robert Gonzales, Bobbi Morse and Leo Fitz

Robert Gonzales personally approached Fitz and Jemma Simmons as they stared at the Toolbox. He told them that he wanted them as his field agents, but Phil Coulson approached them first. Gonzales wanted Fitz to access the Toolbox. Simmons asked what would happen if he refused. Bobbi Morse explained that he could leave after he was evaluated and debriefed. Fitz told her that he was leaving to pack his belongings.

As he was packing, Alphonso Mackenzie approached him, calling Fitz by his nickname "Turbo." Fitz pointed out only his friend Mack would call him that, meaning that he no longer considered Mackenzie to be his friend since the betrayal. Mackenzie told Fitz that he would always be his friend and asked him not to leave, but Fitz continued to refuse. As they were talking, Mackenzie revealed that Simmons was working on accessing the Toolbox using Phil Coulson's DNA. Horrified that Simmons might have began working for Robert Gonzales, Fitz decided to investigate.

Fitz went to the Holocom and learned what Simmons was doing. He ran to Simmons' laboratory, asking why she was betraying Coulson and forcing him to leave. He grabbed the Toolbox and agents drew their weapons to have him release it. Fitz pitied them for their betrayal and their lack of trust in Coulson. Fitz then realized that Simmons wanted him to leave, and Simmons admitted that he felt that if they could not work together to unlock the Toolbox, it would probably best that he do so. He then left with Simmons giving him one of his bags.

Catching a taxi cab to the airport, Fitz looked inside his bag and pulled out the real Toolbox from the sandwich bag Jemma Simmons had given him, along with his favorite sandwich which he smelt with delight as he now knew that Simmons had not betrayed him and Coulson but was instead distracting Robert Gonzales with a fact Toolbox. However, he soon found out that Gonzales sent agents to track him under the hopes that he would lead them to Coulson. Fitz took the Toolbox to a diner, where he opened it in the diner's restroom, ignoring the knocks on the door from other customers. He accessed Phil Coulson's tablet from the box and contacted him and Lance Hunter, who were both shocked and surprised to see him. However, other patrons, who were in fact Robert Gonzales' agents in disguise, began to become impatient and continued to bang on the door. Fitz asked Hunter for advice on finding a way out, and Hunter began describing an escape method.

Seeing Ward Again
"Desperate times, desperate measures. Count me in." "I'm relieved to hear you say that, we're making a deal, with Ward"

- Leo Fitz and Phil Coulson

Fitz ran to the roof of a building and was picked up by Phil Coulson, Lance Hunter, and Michael Peterson, whom Fitz asked about his upgrades. He then gave Coulson the Toolbox and was briefed on their mission. Coulson explained that Skye had been taken by a teleporter and their only chance of finding her was to question HYDRA's current leader Baron Wolfgang von Strucker and Doctor List. When finding out that they would have to work with an enemy, Fitz agreed to it right away. However, upon hearing that they would be working with Grant Ward, Fitz was horrified.

Hunter pointed out that their jobs sometimes required them to work with people whom they despised, comparing the situation to his own frustration with working with Bobbi Morse again. When Coulson and Deathlok brought in Grant Ward and Agent 33, whom Ward had started dating, Fitz sat on an opposing side of the Quinjet, fingering his gun while Hunter tried to keep him calm. When Ward asked how Fitz was doing, Fitz lost his temper and leaped from his seat at him only to be held back by Coulson and Hunter. Once he had expressed his belief that Ward would betray them the first chance he got, Fitz calmed down, but still refused to answer Ward's question. When a brainwashed Sunil Bakshi set up a meeting with List, Fitz watched through Deathlok's eyes with the others. Bakshi offered up Deathlok as incentive, causing the Quinjet to erupt into violence, and Agent 33 held a knife to Fitz's throat. As the standoff continued, Fitz was the only one who noticed that Deathlok was targeting everyone in the HYDRA meeting. He told the others, and the standoff ended. Fitz told Deathlok to play along. Later, when the rest of the team followed List to a building in Milwaukee, Fitz stayed behind in the Quinjet as backup while everyone else entered the building. The mission failed, resulting in Skye and Calvin Zabo once again disappearing with the teleporter, during the battle Deathlok was captured by HYDRA and Lance Hunter was wounded. As a result Coulson turned himself into Robert Gonzales and the two worked out an arrangement to stop HYDRA. Coulson had Fitz, Hunter, Ward, and Agent 33 board the plane and fly back to the Playground. As they were doing so, Fitz talked briefly with Hunter, asking him about his wounds. Hunter replied that he was in more pain from seeing Ward and Agent 33 talking to each other like a couple.

Attack on the Arctic HYDRA Research Facility
"Can we just address the elephant on the plane? I know. This is weird. Mistakes were made." "By you." "And people got hurt." "By you."

- Grant Ward and Leo Fitz

After they returned to the Playground, Fitz and Jemma Simmons spoke about Grant Ward. Fitz told her about his attempt to kill him, and she seemed to be impressed. Simmons told him how she could kill him with a Splinter Bomb, but Fitz was worried about her because he realized she was serious. Phil Coulson decided to take Fitz, Melinda May, Simmons, and Ward on the mission to save Deathlok and Lincoln Campbell, who were imprisoned at List's base.

Preparing for the mission, Fitz and Simmons both expressed their mistrust toward Ward. Fitz expressed his wish to kill Ward, and Simmons suggested that they could, revealing that she planned to kill Ward with a Splinter Bomb.

As they got on the plane, Gordon teleported Skye onto it, reuniting her with her old team, much to Fitz and Simmons' pleasure. Fitz and Simmons eagerly asked her lots of questions about where she had been and about her powers, but Skye was reluctant to answer them with Ward around, but she promised that she would tell them everything soon.

Ward prepared to update the team about their mission; Fitz stood and watched him. Ward sensed the team's hostility towards him, so he tried to apologize for betraying the team, admitting that that was what he regretted most, not even ejecting Fitz and Simmons' pod into the ocean. He tried to remind the team of the good times that they had, but everyone, including Fitz, remained unmoved by what he said and expressed their anger towards him.

After the team sacrificed the Bus to get into List's base, Fitz went with Coulson and May to break into the missiles system and gather information about HYDRA, while Simmons went with Skye, Ward, and Sunil Bakshi to save Deathlok and Campbell. After Fitz succeed in his mission and the abducted were saved, the team returned to the Playground and the base was destroyed. He and Simmons talked with Deathlok and said to him that there was facility which had the equipment to repair his dismantled leg.

At the Playground
"What if the council is wrong? I mean, Gonzales is never..." "It's not the council verses us, Fitz. Not anymore."

- Leo Fitz and Phil Coulson

Fitz and Jemma Simmons looked at Skye, as she sat near the anesthetized Lincoln Campbell. Then, they informed Kara Palamas that the brainwashing of HYDRA was not affecting her reactions anymore. Palamas thanked them but then the light of the building turned on and off, as Campbell awoke from his coma. After S.H.I.E.L.D. located the Inhumans' base, Afterlife, Fitz and Simmons were with Skye and said their goodbyes before she returned to the base as a part of S.H.I.E.L.D.'s plan reaching an agreement with the Inhumans with their leader, Jiaying, who was also Skye's mother, and putting them in the Index. Before Simmons went to Afterlife as the agent-in-charge of the Index process, Fitz talked with her and admitted that he had wanted to kill Grant Ward but was unable to do it and was glad that he did not become a murderer. He was also glad that Simmons did not kill Ward either, but Simmons admitted that she had indeed tried to kill him.

Fitz was in Coulson's office along with Coulson and Lance Hunter while S.H.I.E.L.D. was on the way to meet the Inhumans. Hunter doubted Coulson's decision of sending Robert Gonzales to meet Jiaying and not him. Even Fitz questioned the council's decision, but Coulson said to him that it was not the council versus them anymore and they were right about their decision. He said that he had not always made the right call, especially where it had came to Skye, and if they did not trust the council, S.H.I.E.L.D. would fall again. Hunter joked that S.H.I.E.L.D. would fall again if a dozen enhanced people will bring terror on them, to which Fitz agreed. Coulson then said that he thought that they had spent too much time together. Just then, Melinda May informed them that the Inhumans turned over Calvin Zabo, to which Coulson said that they will deal with this when they had returned to the base.

Finding Bobbi Morse
"Figured out what happened to Agent Morse. She left on a Quinjet with... you."

- Leo Fitz

After a while, Melinda May talked with Phil Coulson, saying that Bobbi Morse had not arrived at Afterlife yet. Coulson sent Lance Hunter to check what had happened to her. Suddenly Jemma Simmons joined the conversation and said that Robert Gonzales had allegedly shot Jiaying. Fitz said that he had got what he always wanted, but Coulson said that Gonzales had not done this and ordered them to find him.

Fitz then joined Hunter in the search for Morse. He checked the flight records from the base and saw that Morse had left the base with a Quinjet before the three others left for Afterlife. Hunter told him to change access and check the security cameras to the time before she left the the base. Fitz discovered that May had left the base twice; one time with Morse and the other time with the delegation of S.H.I.E.L.D. to Afterlife. Hunter realized that it was Agent 33 who was disguised as May and took Morse on a Quinjet. Fitz asked Hunter what Agent 33 wanted with Morse. Shocked by their discovery, they went to Coulson's office and showed the footage to Coulson, Melinda May and Jemma Simmons. Hunter said they found where the Quinjet was and May volunteered to take him there.

Calvin Zabo's Transformation
"Fitz, I'm open to suggestions." "I.C.E.R.s are a good start." "Agreed."

- Leo Fitz and Phil Coulson discuss defusing Calvin Zabo

Calvin Zabo was brought to the Playground and interrogated by Phil Coulson; Zabo soon afterwards had a heart attack. He was brought to the lab where Jemma Simmons tried to revive him. Failing, she asked Fitz for an adrenaline syringe. She injected him, but it caused Zabo to transform into a powerful monster. In the moment Zabo was locked up in the medical pod, trying to get out, Coulson asked Fitz for suggestions and Fitz said that I.C.E.R.s could be a good start. As Zabo escaped from the pod, Fitz, Coulson and Simmons started shooting at him with the I.C.E.R.s, but they had no effect on him. Coulson ordered Fitz and Simmons to get out of there. Shortly after, when Zabo walked around the base, Fitz and Simmons lured him into the hangar where Coulson could reason with him.

Preparing for a Counter Strike
"Sir, good news. I've modified my field generators to act in unison as a quantum-field disrupter." "Great, you're saying you found a way to shut down Gordon's teleportation ability?" "Well, now my news sounds less good." "Oh, sorry."

- Leo Fitz and Phil Coulson

Phil Coulson convinced Calvin Zabo to assist them against Jiaying, and Zabo was put under armed guard while Jemma Simmons helped counteract the effects of his formula, resulting in the reverse of his physical changes. Fitz then informed Coulson that a distress beacon from the Iliad was expanded to all of S.H.I.E.L.D. channels. Coulson realized that the Inhumans had hijacked the ship while they were fighting Zabo. Coulson asked Fitz if he got Lance Hunter and Melinda May on the line, but he responded that he could not communicate with them. Fitz then came to Coulson's office to inform him that he had built Quantum Field Disruptors that could make Gordon stay in a single location. Fitz and Coulson visited the room where Bobbi Morse would be analyzed since she had been badly injured. Coulson asked Simmons if Zabo was stable enough to join them in their mission to retake the Iliad, but Fitz and Simmons were surprised to hear that.

While preparing himself for going with Phil Coulson, Melinda May, and Calvin Zabo to retake the Iliad, Fitz was visited by Jemma Simmons. She started to explain that after she saw Lance Hunter with Bobbi Morse, she realized that they had never spoken about what Fitz had said her in the bottom of the ocean. Fitz was surprised to hear that. He said to her that there was nothing to be said about about it, but Simmons said that maybe there was. Coulson then came and informed Fitz that they were on the move, so Fitz followed him, leaving Simmons standing alone and crying to herself.

Hijacking and Retaking of the Iliad
"I'm trapped in here! That's not possible! What did you do?!" "Science, biatch."

- Gordon and Leo Fitz

In one of the Quinjets heading to the Iliad, Fitz informed Coulson that someone had changed the S.O.S. signal. Coulson realized that it was Skye who had done that and Fitz said that she warned them that they were flying to a trap. Coulson ordered the other Quinjets to fall back while they still flew to the ship. As they landed on the the ship, Fitz got another message from Skye, which warned them about synthetic Terrigen Crystals in the HVAC room. Zabo then understood Jiaying's plan: she wanted to use the Terrigen Mist in the crystals to kill all the S.H.I.E.L.D. agents. Coulson and Fitz went to find the Crystals, while Zabo went to find Jiaying and May went to the HVAC room. The two eventually found Alphonso Mackenzie protecting a box full of Crystals from Gordon. Fitz started to put the Quantum Field Disruptors in their places. As Gordon returned, Fitz activated the devices and they succeeded in preventing Gordon from teleporting to a different location. The three continued fighting Gordon, but he managed to take one Crystal. He then teleported himself directly behind Fitz, but he was impaled by Fitz's iron pole while he was holding it. Gordon then dropped the Crystal, but Coulson caught it. Then his arm started to petrify, but Mackenzie used his axe to cut off Coulson's hand.

New Programs
"I got Fitz working on these designs. We'll need to be mobile."

- Phil Coulson

With the threat quelled, Phil Coulson asked Fitz to work on a new plane for his new program he founded. Fitz also helped Alphonso Mackenzie, who was now the head of the Alien Artifacts Department, to work on the Monolith on the Iliad. Although Jemma Simmons continued to push the idea of examining the Monolith, Mackenzie insisted that they must not open the box in a thousand years as it was too dangerous.

As Fitz and Jemma Simmons worked on the stone, Fitz awkwardly tried to ask Simmons to go to dinner with him, although Simmons at first believed he was asking her to eat generally, she soon realized what he meant and agreed to have a date with him. Fitz leaned on the Monolith's casing and stumbled, causing the lock on the case to loosen. With Simmons having finally agreed, Fitz left the room. Without knowing it however, he had caused the stone's casing to unlock allowing the Monolith to swallow her. Simmons then disappeared without a trace.

Seeking Answers
"I'll open it and give you what's inside, no problem. But only in exchange for something in your possession." "How about in exchange for your life?" "No deal."

- Leo Fitz and Yusef Hadad

Not willing to give up hope on finding Jemma Simmons again, Fitz dedicated his time and work to studying the Monolith in the hopes of finding an answer. This led him to questioning if she had been sent to a parallel dimension or lost to the Quantum Realm like Janet van Dyne. The more questions he asked, the more time he took off from S.H.I.E.L.D.. Eventually he learned of a scroll casing which was said to hold the answer to the Monolith's power; Fitz tracked the scroll to the criminal Yusef Hadad, who had stolen it. Fitz tracked Hadad to Morocco and offered him the contents of his briefcase; Hadad's men captured Fitz and only spoke to him when they discovered the briefcase could not be opened without the password. Fitz explained his reasons for coming and told Hadad that he would only open the case if Hadad gave him the scroll casing. Hadad acquiesced and handed over the casing, ordering Fitz to open the briefcase; Fitz did and handed over the Splinter Bombs inside, explaining that they were the weapons that killed Sunil Bakshi. When Hadad tried to kill Fitz with the bomb, it activated the flash grenade inside. During the ensuing chaos, Fitz escaped with the scroll casing while Hadad's men shot at him.

Never Giving Up
"Do something... Do something!... DO SOMETHING!... DO SOMETHING!"

- Leo Fitz to the Monolith

Back at the Playground, Fitz found Phil Coulson waiting for him. Coulson tried to sympathize with Fitz's feelings by comparing his loss of Melinda May to Fitz losing Jemma Simmons; Coulson attempted to convince him to move on but Fitz remained determined. He smashed open the casing and read the scroll, translating the word to "Death". Seeming to accept this as the final confirmation that Simmons had been killed by the Monolith, Coulson comforted Fitz and told him it was time to finally move on and continue with their work. Unable to accept that Jemma Simmons was dead, Fitz, after Coulson left, grabbed a shotgun and charged into the room containing the Monolith, ignoring the warning signs and kicking open the door. Without hesitation or fear, Fitz shot the locks of the Monolith's casing and stepped into its protective box. Fitz at first quietly spoke to the stone, asking it to do something and give him an answer; when nothing happened, he began to lose his temper before screaming at the stone and demanding it to do something, all while punching and kicking it to make it respond. Despite his screams, tears and strikes, the Monolith remained a stone and did not give him the answers he sought. Lance Hunter and Bobbi Morse then charged into the room followed by Phil Coulson, Alphonso Mackenzie and Daisy Johnson. They pulled Fitz away from the Monolith and locked its case seconds before it transformed into its liquid state again. Coulson berated Fitz over being so foolish, noting that he had already lost Jemma Simmons to it and could not afford to lose him too. Fitz apologized but assured him that he would never give up on finding his friend. As he sat on the ground, Fitz noticed a strange sand on his fingers which he had gained from touching the Monolith; seeing the sand gave Fitz an idea and he ran from the room. Once he had confirmed his theory, Fitz called the team into Phil Coulson's office where he pitched them the idea that the sand was impossible and should not exist; therefore, it must confirm that the Monolith is a transportation device and had sent Jemma Simmons to another point across the universe. Coulson tried to make Fitz accept that it was possible that although he could be correct, Simmons may well be dead anyway having been lost for months; this did not stop Fitz and they agreed to continue researching his theory. While Fitz confirmed what he needed, Coulson sent Lance Hunter on his mission to hunt down and assassinate Grant Ward.

Help from an Asgardian
"You'll have to go through me." "And I could. Literally."

- Leo Fitz and Elliot Randolph

Fitz joined Phil Coulson and Bobbi Morse in traveling to Norway to seek the help of the Asgardian professor Elliot Randolph, who had been arrested for getting drunk and damaging property. Although Randolph initially made it clear that he had no wish to help as he was trying to keep his Asgardian powers quiet due to the recent fears of the public, Fitz made it clear they did not have time to wait and Coulson was able to change his mind with a threat of handing him over to the ATCU. Randolph reluctantly agreed and ripped the bars off his cell and left with them. Returning to the Playground, Randolph looked at the Monolith and was fascinated, having never seen such an artifact before. As they discussed its powers, Randolph made it clear that they should destroy it; Fitz assured him that he would have to go through him first. Not wishing to kill Fitz, Randolph relented and asked for more information. The team told him about the scroll which Fitz had recently recovered and Randolph recognized the writing from a castle he had visited hundreds of years ago. Confirming his thoughts, Randolph told everyone to join him in the plane to investigate.

Further Experiments
The team traveled to England to the castle which Elliot Randolph had visited all those years earlier. Randolph confirmed that it was the same castle and described the party he had attended there where he had seen the writing on the walls of the castle. The group found the writing and before long, Phil Coulson found a secret passage leading to another room which Randolph had never seen before. The room was filled with ancient machinery and a trap door which seemed like the perfect size to hold the Monolith. Once they confirmed the room was designed to test the Monolith's power, Coulson called Alphonso Mackenzie and ordered him to bring it to them. Although reluctant, Mackenzie brought the Monolith to them in Zephyr One and they set it up for their experiment. Fitz led the team in setting up their equipment as they worked out how to work the machinery. They turned on the machine which triggered a vibration that caused the Monolith to transform into liquid; Fitz looked down at it and called out to Jemma Simmons. Demanding more light to see, Phil Coulson threw Fitz a flare gun which he fired into the liquid, making it instantly vanish. Before they could get their answers however, the machine broke and the Monolith returned to stone. The vibrations also caused Daisy Johnson to collapse as she complained of a terrible noise which nearly killed her.

Saving Simmons
"And you dove through a hole in the universe for me."

- Jemma Simmons

Despite the machinery being broken, Fitz worked out that Daisy Johnson could use her powers to trigger the same effect. Johnson agreed despite the terrible effect it would have on her and the experiment was set up for a second attempt. Johnson used her powers to create a small earthquake which caused the Monolith to turn to liquid; while Coulson and Bobbi Morse set up a video feed to drop inside, Fitz attached a rope to himself and jumped inside. Fitz fell onto a desert planet in the middle of a sandstorm. Without hesitation, he began to desperately call out for Jemma Simmons. To his shock, Simmons answered him and he saw her appear from behind a rock. The two friends called out to one another and desperately fought against the powerful winds to reach one another. However, back on Earth, Johnson struggled to control her powers and to keep the Monolith liquid, forcing Phil Coulson to order that Fitz be pulled back. Fitz was just able to grab Simmons' hand as he was pulled back into the portal. The moment the pair were sucked back to Earth, Johnson collapsed and the Monolith exploded. Fitz hugged his friend and smiled to the team as they celebrated their victory. Once she had gone through medical tests and deemed to be safe from infection and physically well, Simmons was allowed to go to sleep aboard Zephyr One. Fitz stayed by her bedside while she slept. Once he had fallen asleep, Simmons awoke from a nightmare and attempted to defend herself with a blade. However, once she remembered where she was, she turned to see the sleeping Fitz sitting beside her. Simmons found comfort resting on Fitz's lap and fell into a more peaceful sleep.

Caring for Simmons
"A very persistent young man here. We've been holding this reservation for months. I'm delighted you're finally here." "You kept the reservation." "Don't make a fuss. It's not a big deal. I remember when you took me out after months in the hospital. It made me feel like a human being again."

- Maître d’, Jemma Simmons and Leo Fitz

Fitz and the team discussed the physical changes Jemma Simmons had experienced in the other world. He then helped her adjust to the Earth gravity and accompanied her to the lab, where Bobbi Morse welcomed her. She then saw the remains of the Monolith. Fitz noticed that small noises diverted her attention and Simmons told him that she wanted to go to her room to relax.

He then spoke with Morse about how distanced Simmons was. Morse told him that Simmons needed a fresh start to learn how to live again on Earth. Fitz then left the room and reserved a place in a restaurant for him and Simmons.

He brought Simmons to the restaurant and told her that the reservation had been waiting for months and he planned it so that they would eat alone. Simmons said she did not know what to say for what he had done for her, so Fitz said that she did not have to say anything. But as she started to cry, Fitz sat next to her and comforted her.

Supportive Friend
"Please, Fitz, I need you to understand." "I understand everything, Jemma." "Well, then why won't you talk to me? What are you doing?" "We're gonna get him back."

- Jemma Simmons and Leo Fitz

Fitz was sent with Bobbi Morse to Hollywood, California to gather evidence from the apartment of Shane and Lori Henson, two Inhumans killed by Lash. Fitz became annoyed with Morse because she had difficulty adhering to the system that he and Jemma Simmons had developed. He asked Morse if Simmons revealed anything to her about her experiences on the other planet; Morse lied, saying that she knew nothing. Returning to the Playground to analyze the samples, Morse alerted Fitz when the hair sample of Lash began to dissolve. While discussing the strange occurrence, and if Morse had somehow contaminated the sample, Fitz found a notebook filled with research on the Monolith. Simmons ran into the lab and abruptly grabbed the notebook from Fitz, causing the paper to fall to the floor. Collecting her research, Simmons told Fitz to leave her things alone as she left.

Later, Fitz went to Simmons' room and asked her why she was researching the Monolith; Simmons decided to give him full disclosure about her experience on the other world. After telling him about her ordeal and her relationship with Will Daniels when she gave up hope of being rescued, Fitz left the room without speaking to Simmons. She, teary-eyed, begged him to understand her feelings. Fitz told her that he did understand her feelings and showed her his computer screen; it revealed the research that he had done over the past six months that she had been absent to locate her. Fitz declared that they would save Daniels and return him to Earth.

Research
"What? You don't think I should help Simmons rescue Will?" "Do you think you should? He's the competition."

- Leo Fitz and Lance Hunter

Fitz was assigned to act as technical support for Melinda May and Bobbi Morse as they went to the Cayman Islands in search of Werner von Strucker, so he allowed his computers to run simulations pertaining to the Monolith as he made cover aliases and backgrounds. Lance Hunter, having been reassigned for his actions in the Attack on Grant Ward, entered Fitz's workplace, seeking something to do. Hunter asked Fitz why he was helping Jemma Simmons to rescue Will Daniels, a man about whom he knew nothing, when Fitz had feelings for Simmons; Fitz did not answer, asking Hunter why he was there. Hunter wanted to help him, but Fitz quickly asked him to leave when he began touching the computers.

During their undercover mission, Morse needed background information on Jerome Deschamps in an attempt to diffuse a situation; Fitz did the research and conveyed the information to the sunglasses Morse wore.

Evaluating the fake IDs and passports found in Strucker's lock box, Fitz determined that Strucker was in Lisbon, Portugal and told Morse and May. Meanwhile, Simmons was behind him, finishing her technical support for Daisy Johnson; she then asked Fitz how his research into the Monolith was progressing. He said that the simulations had not yet found a solution. After Simmons left, Fitz returned to reading background information and newspaper articles on Daniels.

Accessing Simmons' Phone
"I heard your recordings and saw your video. Didn't know you thought about settling down in Perthshire. That's in Scotland." "I know where it is, Fitz." "So when you said all those things about... I mean, you were tired and dehydrated." "I was as clearheaded then as I've ever been when I said all those things. What do you think we should do about it?" "For now let's just watch the sunrise."

- Leo Fitz and Jemma Simmons

Jemma Simmons asked Fitz to fix her phone that she had used during her survival on Maveth; Fitz uncovered some of her files, which included a video of Simmons' birthday party in 2014. Fitz watched in awe and shock as he witnessed her submitted logs and images about the groundbreaking realities of the planet and that of Will Daniels.

After he had given the fixed phone to Simmons, Fitz questioned her about her entries, wondering about her state of mind as she placed them; Simmons, knowing that he was referring to her affirmations of love and wanting a family with him, assured him that she had full clarity when she made her statements. He then too watched the sun rise. Continuing his research, Fitz noted to Bobbi Morse and Lance Hunter that Daniels had a symbol on his uniform similar to one he had seen in the English castle, weeks ago. Morse thought that NASA had sent Daniels through the Monolith, but Fitz gave a theory believing that an ancient order truly sent Daniels; Hunter dismissed Fitz's conspiracy theory as lunacy.

HYDRA's Revelation
"You think that I'm not angry? I'm sick to my stomach! I'm furious, but not at you! 'Cause we're cursed! The bloody cosmos wants us to be apart!"

- Leo Fitz to Jemma Simmons

Continuing research into his theory, Fitz had scrolls and books brought to the lab. The agent moving the books dropped them, and Fitz angrily confronted him over his carelessness. Jemma Simmons calmed him down, before becoming angry with him when he mentioned bringing back Will Daniels. She returned to the lab, and Fitz followed her, asking her why she was angry at him. Simmons replied that she was angry with herself for bringing him into her search along with being angry with him for being so willing to bring back Daniels. Fitz retaliated, saying he was incredibly angry and sick, not at Simmons but at the cosmos for keeping them apart.

Though Simmons disagreed, Fitz listed all the obstacles to their relationship, culminating with Daniels. Fitz asked Simmons if she loved Daniels, to which Simmons hesitatingly answered yes. Fitz agreed and began listing all of Daniels' character traits, saying that he had done everything for Simmons. However, Simmons cut him off and reminded Fitz that he had jumped through a portal to rescue her. Fitz stared at Simmons for a second, then kissed her. Simmons kissed him back, but Fitz broke away and mouthed 'I love you' to Simmons before whispering that they were cursed and walked away.

Fitz was called back by Simmons when she noticed that a book that had fallen off the desk had opened to a page with a symbol similar to the modern HYDRA insignia. The two realized that HYDRA was behind Distant Star Pathfinder and had been sending people through the portal for centuries. Fitz and Simmons revealed their research to the other agents, laying out paper with each insignia, beginning with the Distant Star Pathfinder logo and continuing to the HYDRA symbol. Their research showed that HYDRA was inside NASA and the Advanced Threat Containment Unit.

Kidnapped
"I'm curious which is worse for you. Those moments when Simmons screams or is it the long pauses when she doesn't?"

- Grant Ward to Leo Fitz

When Rosalind Price was killed by Grant Ward, Phil Coulson sent Fitz, Jemma Simmons Luther Banks, and a team of agents to an abandoned Project Distant Star Pathfinder facility in search of clues to the Monolith. While there, Simmons expressed her belief that it was unlikely they would find anything, but Fitz replied that they still could find something to help them bring back Will Daniels. Simmons told him that they could not bring him back, but Fitz said that they now knew exactly where the portal would open on Maveth, so they had to go there. Simmons told him that it would be selfish to potentially allow HYDRA to achieve their goal, but Fitz said that the HYDRA leader was only a legend. Suddenly, the two heard shots. Quickly turning, Fitz saw Banks shoot the other agents, then turn the gun on the two. Fitz asked Banks not to shoot them; however, Banks managed to say it was not him before the gun floated out of his hand, turned, and shot Banks in the head. Fitz and Simmons watched as Giyera entered the room and ordered them to follow him.

In the HYDRA Castle, Fitz and Simmons were brought to Ward and Gideon Malick. Fitz refused to help them open the portal, but Malick claimed that they did not need their help, so Simmons understood that they did not know how to bring someone back from there. Fitz and Simmons refused to cooperate with them, so Ward ordered to separate between the two. Fitz was tied up to a chair and heard Simmons' cries from the other room, and Ward told him that he could end this by telling them what they need.

Entering Maveth
"I lost you once. I can't lose you again. I'm just... not strong enough to live in a world that doesn't have you in it."

- Leo Fitz to Jemma Simmons

Unable to stand hearing Jemma Simmons being tortured, Fitz agreed to enter the portal and guide HYDRA's team. Entering the portal chamber, Fitz saw Simmons restrained by Giyera. She broke free from his hold and ran to Fitz; when Giyera started after her, Fitz told him that the deal was off if he touched her. Simmons begged him not to go, but Fitz assured her that the only thing he would bring back would be Will Daniels. Hugging Simmons, Fitz saw Grant Ward enter the chamber in full combat gear. Asking him what he was doing, Fitz learned that Ward was leading the HYDRA team. The portal opened and Fitz, Ward, and the other agents jumped through. Once through the portal, the team began searching for It. Hiking up a rise, Fitz tried to distract Ward by showing him the program he was using to find the exit portal, before going for Ward's gun. However, Ward realized his intent and kicked Fitz down a ridge before following him down and threatening that Simmons would die if he did not return, and it would be Fitz's fault. One of Ward's soldiers called out for him to come and he walked away. Fitz followed him to the soldier, where he saw an old structure in the shape of HYDRA's symbol. Fitz continued on with the team. Fitz realized that the area that they were walking through was familiar; looking around, he noticed a metal hatch in the ground. Knowing he had found the home of Will Daniels, Fitz entered the hatch, with a furious Ward following him. Once in the cave, Fitz found what he believed to be Daniels with an injured leg on his bed. "Daniels" sat up and questioningly recognized him; Fitz confirmed that it was him as Ward stormed in, angry that Fitz had entered the cave without permission. Fitz panicked as Ward threatened to shoot "Daniels", hastily explaining that "Daniels" was to be their guide and he was the only way to find It. Ward noticed the insignia on "Daniels"' suit and agreed to take him, first offering Fitz the chance to shoot him. Fitz told Ward to grow up and once he had confirmed that "Daniels" could walk, the group left the cave. Walking with "Daniels", Fitz explained that Ward was part of an organization dedicated to bringing back their leader, It. Fitz listened as "Daniels" informed him that they were in the 'no fly zone'. Fitz listened as Ward asked "Daniels" what the structure they had seen was; "Daniels" told him that it was a shrine to It, and that It had lived there. "Daniels" formed a plan to escape from Ward and ordered Fitz to follow his lead. As they continued, a sandstorm began to form, and the team eventually had to shelter behind some rocks. Fitz watched as "Daniels" killed the two HYDRA agents sheltering with them, and he and "Daniels" crept away before Ward realized their escape. Fitz and "Daniels" continued on towards the exit point. As they walked, Fitz saw an ancient city, and asked "Daniels" about it, asking why Simmons had not told him about it. "Daniels" replied that she had never seen it, and explained that there were nine such cities, and the inhabitants had torn each other apart. Suddenly, "Daniels"' leg gave out and he fell. Fitz ran to him and pulled the bandage away to try to assess the damage; he saw only bone and rotting flesh, and realized that what he had believed was Will Daniels was in reality It, inhabiting Daniels' corpse. It began attacking Fitz, who held It off for a time, but was beaten back. Just as It was about to crush Fitz with a rock, It was shot by Phil Coulson. Fitz got up and watched Coulson fight Ward, before realizing that It had also regained its feet and had begun walking towards the now-opened portal. Fitz found a gun and shot It again, but It continued on. Finally, Fitz discovered his flare gun and engulfed It in flames, finally stopping the dark Inhuman. Realizing that the portal was about to close, Fitz screamed for Coulson. Fitz watched Coulson kill Ward, before both entered the portal and were rescued by Alphonso Mackenzie, back on Earth as they made their hurried escape. Getting onboard the Containment Module, Fitz, Coulson, Mackenzie and Daisy Johnson managed to escape the HYDRA Castle just as it was destroyed by missiles. Reaching Zephyr One the group reunited with their friends and teammates while Fitz watched as Simmons searched for Daniels inside the empty Containment Module, before realizing he was not there and turning back to Fitz as she began to cry. Fitz hugged Simmons to comfort her over the loss of her friend and lover, and shared a look with Coulson, knowing that Coulson had killed Ward in cold blood.

Missed By Simmons
"I miss you." "I'm here. Together. We're..." "Professional. And matter of fact, and there's this chasm in the middle of the room of all these things."

- Jemma Simmons and Leo Fitz

While he was in the lab, assisting Jemma Simmons, Phil Coulson asked Fitz to come with him. He asked Fitz's opinion on Lincoln Campbell, so Fitz replied that Campbell had helped Simmons understand the Inhumans' biology. Fitz also told Coulson that he felt guilty for what he had done to Will Daniels. Coulson explained that he had made the hard choice and then ordered Fitz to set up the Theta Brain-Wave Frequency Machine. At first, Fitz refused, but Coulson said that it was for Werner von Strucker, who might know where Gideon Malick was. Coulson eventually got the information. Later, Fitz finished working on Coulson's new robotic hand, as Simmons entered the lab and said that she missed him. Fitz was confused, but Simmons explained that she missed their partnership because of the recent events. Fitz told her that maybe there had been a way to save Daniels, but Simmons said that he was extraordinary, since he had been fully supportive of her since she had returned from Maveth and killed Hive. Together they restored the moment they had met, reintroducing themselves in an attempt to start over.

Potential Cure
"Creel's blood is protecting hers." "A vaccine against Terrigenesis." "Potentially."

- Leo Fitz, Lincoln Campbell and Jemma Simmons

Fitz made a device for Phil Coulson that could replicate people's fingerprints. As he brought it to Zephyr One, he spoke with Lance Hunter about the Inhumans symposium. Later, Carl Creel was brought to the Playground and put inside a Containment Module. Fitz and Jemma Simmons asked him how he had touched the Diviner without being killed, but he did not know. They decided to test his blood samples with Terrigenesis. The two showed Lincoln Campbell that Daisy Johnson's pre-Terrigenesis blood reacted to the Terrigen, but as they mixed it with Creel's blood, it broke down the Terrigenesis. They theorized that it could be a vaccine to Inhumans that were not yet transformed. Johnson entered the lab, shocked at the idea. Fitz and Simmons left the room to let her and Campbell talk.

Losing Friends
"Fitz is here" "It's the Spy Goodbye."

- Lance Hunter and Bobbi Morse

Bobbi Morse and Lance Hunter followed Gideon Malick to Siberia and the rest of the team followed them. Fitz, on Zephyr One, helped the pair to go to a massive compound in the wood. Morse and Hunter were caught after they entered the building. Phil Coulson asked Fitz to activate an EMP in Morse and Hunter's investigation room by his signal, but no signal was made. Coulson returned from where they had been interrogated, saying that in order to keep S.H.I.E.L.D. a secret, the two had been disavowed from the agency. Later, the team went to a bar where Morse and Hunter were. Without directly contacting them, Coulson and the others all ordered shots for the two, saying goodbye in the only way they could.

Almost Imploded
"Sooner or later, this bomb is gonna go off. And then I'll implode. Which is gonna be messy."

- Leo Fitz

Following the Attack on the ATCU Headquarters by the Watchdogs, Phil Coulson sent Fitz Daisy Johnson the the scene. Fitz discovered that the Watchdogs had use Nitramene to collapse the building. Johnson sent the information to Coulson, who suspected Felix Blake had to do with the incident. Fitz heard Johnson and Alphonso Mackenzie weather they should let her using her powers to interrogate members of the Watchdogs. Ftz then helped Johnson interrogating a Watchdog member by pointing a gun at him, despite his unwillingness. After he told them the location of the Watchdogs base, they went there. Fitz sent a D.W.A.R.F. to a barn where they saw Blake. However, one of the Watchdogs shot a Niteramene at Fitz's neck. Johnson could not defect it, so Fitz realized Blake had improved it. In a Containment Module, Fitz learned from the member how to defect it. After Johnson saved him, the member told them the Watchdogs were after Mackenzie.

Spacetime Theory
"Was that Ward?" "Unfortunately, I think it was something else."

- Lincoln Campbell and Leo Fitz

Daisy Johnson saw a vision of the future from the Inhuman Charles Hinton. After she returned to the Playground, Johnson told the team she would fight HYDRA to rescue Hinton from them and Fitz and Jemma Simmons would hold hands as the snow falls. Johnson said they could change the future from happening, but Fitz explained to the team that time was an illusion of the fourth dimension, therefore the future could not be changed. Phil Coulson suggested they would send Melinda May to the mission.

Johnson gave details of the location of the battle to Fitz and Simmons, and they used S.H.I.E.L.D. services to find it. May entered the room and demeaned they would not use all of them. Simmons explained that she and May used some of the services to find Lash. Fitz joined Simmons, Lincoln Campbell and others as they began training to ensure Melinda May would undergo her mission as fast as possible in order to change the vision's outcome. Despite Fitz's doubts, Johnson made sure the room was laid out as accurately as possible to the vision she had had while Fitz and the other agents acted as the guards who needed to be taken out. Eventually May managed to beat the time limit.

They eventually found the location of the battle, which was owned by Transia Corporation. Coulson said he had heard of them so Fitz said he had used their technology for his prosthetic hand. Coulson gave his last orders to May when suddenly the alarms in the base went off, telling them that there was an intruder. Andrew Garner was brought into the base and explained that Lash was taking over and he wanted to say goodbye to May.

May was ordered to stay behind so she could say goodbye to her ex-husband while Johnson went into the mission and Fitz managed to hack into Transia Corporation's CCTV feed. In Coulson's office they watched as they managed to hack into the Transia Corporation's CCTV feed. As they spotted Giyera on the feed, suddenly the video seemed to show Grant Ward in the building. Fitz claimed it was likely to be Hive. They went to the building to save Johnson and find Ward. Fitz and Simmons stayed outside. Seeing no cloud in the sky, Fitz said that maybe Johnson had not seen the future. Suddenly, Fluorescent sparkles fell from the building's rooftop, so Fitz realized Johnson had not seen snow. Simmons said they supposed to hold hands now, so the two did it.

Studying Hive
"You were left no choice on that planet. You did the right thing, but I crossed the line. Ward deserved to be punished, but no one deserves to have the life s..." "No, he did deserve it. He did deserve to have his chest caved in no question."

- Phil Coulson and Leo Fitz

Fitz, Jemma Simmons, Daisy Johnson and Alphonso Mackenzie examined skeletons sentenced from the skin by Hive. Fitz explained that Grant Ward's body was possessed by the Inhuman from Maveth. The team was called to Phil Coulson's office for a meeting where he explained that in order to find Hive, they would go to GT Agrochemical facility which had been raided by HYDRA. On Zephyr One, Fitz and Simmons explained to Coulson that Hive had created small organisms which had consumed the victims' flesh. As the team prepared to enter to facility and to face Giyera there, Fitz explained them his powers. Melinda May asked him about a room in the facility where she could defeat him. After they kidnapped Giyera, Fitz found that the data of the facility had been moved to an oil field in Schoonebeek. Fitz found a frustrated Coulson. He asked him if he was fine, so Coulson explained that in contrast to the justified act against Hive Fitz had done on Maveth, he should not had kill Ward. Fitz tried to conform him by saying Ward had to die, but Coulson said that now he Ward was basically after him. Fitz then was near to the Containment Module where Giyera was inside it. Suddenly he noticed that one of the seat belt was missing a buckle. Giyera used it to escaped the module and Fitz set the alarm. He pointed a rifle at Giyera but the latter managed to take it. Fitz revealed it had no bullet so Giyera threw it towards Fitz but he missed. Mackenzie tried to beat Giyera but he failed and Giyera managed to bring the plane to the oil field.

Battle at Gideon Malick's Headquarters
"Sorry. I know everything about Will and starting over. Didn't mean to push too fast." "Too fast? Fitz, it's been ten years. We can't waste any more time."

- Leo Fitz and Jemma Simmons after their kiss

Fitz, Jemma Simmons, Phil Coulson and Alphonso Mackenzie helped a wounded Melinda May to get shelter in a storage room at Gideon Malick's Headquarters. The room was soon assaulted by HYDRA agents who began to ram the door. While Simmons took care of May's wound, Fitz and Mackenzie spread chlorine gas in the corridor, making the HYDRA agents cough and blinding them. The group was then rescued by Elena Rodriguez and Daisy Johnson before returning on the Zephyr One.

Back at the Playground, Fitz and Simmons noticed that the dead body of Lucio, killed by Joey Gutierrez during the battle at Gideon Malick's Headquarters, maintained a high body temperature, and thus placed the corpse in quarantine. Fitz later assisted Simmons during Lucio's autopsy, looking for a way to determine whether one of the S.H.I.E.L.D. Inhumans was infected by Hive. Fitz displayed some discomfort, both because of the autopsy and because of the fact that they could not trust the Inhumans present at the Playground. The two scientists then discovered the signs of Hive infection in Lucio's brain, and reported their discovery to Coulson.

Immediately after that, the power was cut at the Playground. Fitz and Simmons made their way to the generators room and, on their way, discovered the dead body of Malick with a grenade beside it. The grenade exploded, throwing Fitz and Simmons on the ground. They were found by Coulson who ordered them to get some rest in a calm place, with Fitz abruptly rebuking Lincoln Campbell when he offered his help since they still did not know whether he was infected by Hive or not. Fitz and Simmons went to Fitz's bedroom where they kept searching for a test for Hive's infection. Both sitting on Fitz's couch, they contemplated one of his pictures of cosmos, discussing Hive, and Fitz jokingly noted that Hive was unable to leave Maveth without the help of humans. Fitz and Simmons then shared a tender look, holding hands before slowly kissing. Fitz apologized, remembering that Simmons had proposed to start their relationship from the beginning. However, Simmons replied that they had known each other for 10 years and that, since Fitz considered that they were "cursed", they couldn't waste any more time. They kissed again and stayed in Fitz's bedroom until Johnson, who turned out to be infected by Hive, escaped from containment by generating a earthquake which damaged the Playground.

Meeting Holden Radcliffe
"You're the only one that can save my friend."

- Leo Fitz to Holden Radcliffe

Fitz ensured the rebooting of the system with the help of Lincoln Campbell. He later attended the crisis meeting held by Phil Coulson before leaving the Playground with the Zephyr One, along with the rest of his friends. He and Jemma Simmons then informed Coulson that Hive's infection on the Inhumans had the same effect than a drug addiction, making them invulnerable to I.C.E.R. shots. They suggested to make contact with Pr. Holden Radcliffe, a scientist specialized in parasitic organisms who used to work at GT Agrochemical. Radcliffe was fired from the company due to the transhumanist experiments he conducted.

Coulson sent Fitz, Simmons and Alphonso Mackenzie to Romania in order to retrieve Radcliffe. While preparing for the mission, Fitz and Simmons, acting as they were having a professional conversation due to the presence of numerous S.H.I.E.L.D. agents around them, discussed the future of their relationship after the kiss they shared the day before, especially in the perspective of having sex. However, they were interrupted by Melinda May. In Bucharest, Fitz, Simmons and Mackenzie rented a hotel room and prepared for their mission in a private club where Radcliffe was supposed to be. Fitz and Simmons posed as two high ranking geneticists willing to sell an advanced technology to Radcliffe: a variation of the eye technology implanted in Deathlok. Mackenzie stayed in the hotel room, following the progression of his colleagues through Fitz's glasses. Fitz noticed two men staring at them and supposed that they were working for Radcliffe. Approaching them, they were greeted by Anon, Radcliffe's assistant, who asked them if they had made an appointment. Upon learning that they were willing to show their technology to Radcliffe only, Anon requested that Fitz and Simmons waited at the bar until Radcliffe was ready to see them. There, they briefly cut their communications so that Mackenzie could not hear them and they resumed their interrupted conversation about moving further in their relationship. Fitz compared the fact of having sex with Simmons to a singularity, like in transhumanism or in a black hole. Simmons found the metaphor both lovely and terrifying, and the two agreed that their best option was to stop thinking about it and simply doing it. Anon came back to them and invited them to follow her in order to meet Radcliffe. Fitz and Simmons were brought to a small operation room where they were asked to surgically implant the cybernetic eye on a patient in order to demonstrate the efficiency of their technology. They discussed the matter with Mackenzie and resolved to follow Anon's instructions. However, before doing the surgery, Simmons noticed that the eye they were supposed to replace was not of human origin but was instead an avian prosthetic eye. The patient they were supposed to operate was actually Radcliffe himself. Fitz and Simmons presented their technology to Radcliffe, who recognized it as similar to the one used by Cybertek to control their soldiers through explosives implanted in the eye. Fearing that Fitz and Simmons were from HYDRA, Radcliffe ordered Anon to generate an EMP to disable their communications. Distraught, Fitz and Simmons informed Radcliffe of Hive's existence and his ability to infect Inhumans. However, before they could develop, Radcliffe's guards came across the room and tried to take them out. Fitz managed to knock one guard out and explained to Radcliffe that he was the only one who could save Daisy Johnson while Simmons was taken out.

Just as Fitz mentioned her, Johnson blew up the door of the operation room and proceeded to kidnap Radcliffe with the assistance of Alisha Whitley. Fitz tried to stop them, but Johnson used her powers to throw him against the wall. Johnson then smothered Fitz with her powers and demanded that S.H.I.E.L.D. stopped trying to rescue her, stating that she had finally found a family with Hive and that she was willing to hurt any S.H.I.E.L.D. agent who would come near her. Releasing a hardly breathing Fitz, Johnson finally threatened him to kill him if he came for her again before leaving the club. Fitz returned to the hotel room, where Simmons was awaiting him. Simmons told him that Mack was busy at the Quinjet they used to come to Romania, so they were alone in the hotel room. Fitz, putting in practice what he and Simmons had discussed in the club, kissed Simmons and the two finally had sex, taking a great leap forward in their relationship.

Searching for a Cure
Fitz and Jemma Simmons kept trying to elaborate a cure for Hive's infection. They developed an antitoxin which was shown to fight the parasites, but it was also potentially fatal to the immune system. Fitz insisted that it was worth testing. Lincoln Campbell, ready to do anything to help Daisy Johnson, offered to be their Guinea pig. However, Simmons deemed it too dangerous and they had to call for Phil Coulson in order to make a decision one way or the other. To Simmons, Campbell was only willing to try the antitoxin because he was a "lovesick fool trying to make a grand gesture". Fitz, possibly identifying with that description since he had risked his life on multiple occasions to save Simmons, thought that there was a slight chance that it could work. However, Coulson refused that Campbell received the antitoxin and ordered Fitz and Simmons to look for another solution.

Fitz went to find Simmons at the Playground's cafeteria, worried that their disagreement might affect their relationship in private. Simmons reassured him, saying that she did not want a boyfriend who agreed to anything she could say (since she already had that kind of boyfriend). Both agreed that they should not let their disagreements at work endanger their newfound love story. The pair jokingly talked about their time at the S.H.I.E.L.D. Academy on their way back to the lab, only to find Campbell who had seized a syringe and injected himself with the antitoxin. Fitz and Simmons rushed at him but Campbell, on the verge of fainting refused that Simmons gave him a drug to counter the effects of the antitoxin.

Fitz attended to an exhausted Campbell, blaming him for disobeying Coulson and for causing malfunctions in the lab's equipment, since Campbell's electric powers burst out when he injected himself with the antitoxin. Fitz then prepared Campbell so that Simmons could perform a brain biopsy to test the effects of the antitoxin. Fitz and Simmons soon had another patient to take care of : Alphonso Mackenzie had been wounded by Daisy Johnson in an attempt to bring her back to S.H.I.E.L.D. Coulson's team thus learnt of Hive's plans: turning all humans into Inhumans who would serve him while he took over the world.

Hive's Plan
Following Daisy Johnson's infection by Hive, S.H.I.E.L.D. knew that she was able to infiltrate its systems. Fitz decided to take some countermeasures in order to keep her out of the systems, though he knew that he could not repel her attacks forever. However, Melinda May suggested another course of action, and to take the initiative instead of only defending themselves.

Fitz attended a meeting with Phil Coulson and Jemma Simmons, during which they informed Glenn Talbot of the mechanism of Hive's infection. Fitz and Simmons also warned Coulson and Talbot that although Hive could not harvest the Kree blood he needed from the two Krees who had tried to kill him, he had another source of Kree blood : Daisy Johnson. Indeed, since the GH-325 she had been injected with when she was mortally wounded by Ian Quinn was of Kree origin, Hive could use her blood in order to successfully replicate the Kree experiment that he undewent and so transform humans into Inhumans, by creating a virus he just had to spread across the Earth.

Talbot recommended a preemptive strike by the U.S. Army, but Coulson, Simmons and Fitz disagreed. Indeed, Fitz informed Talbot that Hive had stolen something in an ATCU facility in Indiana. At the same time, Fitz received an alert indicating that Johnson was back into S.H.I.EL.D. systems. Fitz and Simmons discovered that she had accessed Lincoln Campbell's containment chamber by fooling them with a loop on the video feeds making them think that Lincoln was asleep while he was actually talking to Johnson.

With the help of Simmons and Alphonso Mackenzie, Fitz locked down the Playground and its systems to prevent Campbell from escaping. However, he forgot to do the same for the Quinjet systems and realized only too late that Johnson had took over on it. A Quinjet flew out of the Playground but contrary to what Fitz, Simmons and Talbot thought, Campbell was not aboard : he made Johnson believe he would join her, while actually he had no intention to do so as long as she was under Hive's influence. Campbell devised this plan with May and instead, they sent Lash to Hive. Indeed, since Lash had once spared the life of Johnson, Campbell thought that his purpose was not to kill her, but instead to kill Hive. Though they were wrong, Lash's intervention cured Johnson from her infection, allowing her to return to the Playground.

Fitz and Simmons asked Johnson about what she experienced beside Hive and she told them about the existence of the Primitives. They understood that if Hive had a way to generate a shock wave powerful enough, he could spread his virus and turn all humans into Primitives. Talbot revealed that he already had what he needed, since the device stolen in Indiana was a warhead.

Cure for the Primitives
"We'll find a cure." "Possibly. In a decade or so."

- Jemma Simmons and Leo Fitz

In order to prevent Hive from launching a missile loaded with his virus, S.H.I.E.L.D. needed to get a missile kill code from the U.S. military. While Glenn Talbot was trying to get one from General Andaz, but the latter refused, saying that it would violate the chain of command. However, Talbot kept him long enough on the line so that Fitz could find the location of the kill codes and duplicate the voice and the image of General Andaz. Fitz then used chroma key compositing and motion tracking sensors to impersonate General Andaz during a video interview with Undersecretary Walter Thomas to obtain the kill code from him. This enabled S.H.I.E.L.D. to stop the launching.

Prior to this, Fitz also helped Alphonso Mackenzie and gave him instructions for the development and the deployment of the Theta Brain-Wave Frequency Machine that Mackenzie, Melinda May, Elena Rodriguez and Lincoln Campbell used against Hive in order to bring back to his mind all the memories of his previous hosts at the same time, confusing him.

Following the success of the operation led by S.H.I.E.L.D, both from the Playground and on the field, Holden Radcliffe was taken into S.H.I.E.L.D's custody and ordered to work with Fitz and Jemma Simmons in order to find a cure for the Primitives that Hive and Radcliffe had created. However, Fitz doubted that they could easily find a cure. Discussing with Simmons, he soon realized that she was planning a romantic trip for both of them in the Seychelles Islands in order to get some rest far from S.H.I.E.L.D.'s agitated environment. Fitz later approved the transfer of the Gel Matrix box in which Hive was locked in. However, he noticed that something was wrong with a shipment of mechanical pieces that were stored next to the cell. Before he could do anything, an explosion happened, spreading a pseudo-Terrigen Mist which turned S.H.I.E.L.D. agents into Primitives. Fitz escaped the mist but was almost killed by the Primitives before leaving the hangar with the assistance of Phil Coulson and Simmons. However, Hive was released by his new Primitives slaves and planned to steal the Zephyr One in order to spread his virus.

Battle of the Playground
"Remember, we don't want to hurt you if we don't have to. People that are under sway, they're not in control of their actions. They're not bad people. Well, except you. You were a murderous wank before all this."

- Leo Fitz to Giyera

While Daisy Johnson was fighting Hive after learning that he could no longer take her under his influence, Fitz went with Melinda May to check on the malfunctioning of her Containment Module. Together, they discovered that Johnson had escaped and was trying to stop Hive. At the same time, 28 Primitives had stormed the Playground and were invading it to take down S.H.I.E.L.D., quicky followed by Giyera, Hellfire and other Primitives. Hive stole the Zephyr One with Giyera and Hellfire and put it in vertical flight in order to drop his virus on Earth, but unbeknownst to them, Fitz and May had infiltrated the plane. Fitz and May found Johnson, imprisoned in the plane's Containment Module, but she refused to be set free, thinking she was a liability. Fitz respected her decision and wet to find some weaponry for May and him. Before they could proceed on the plane, May was knocked out by Giyera, who used his telekinetic powers to steal Fitz's gun and threaten him. However, Fitz managed to play for time by telling Giyera that he had hidden a weapon on the plane to destroy them all and seized an invisible Cloaked Gun to shoot Giyera twice, killing him. He then released Johnson and took a dizzy May with them.

They soon received reinforcements as Phil Coulson, Jemma Simmons, Alphonso Mackenzie and Lincoln Campbell used a Quinjet to get on the Zephyr One. However, Campbell was badly injured fighting Hellfire, so Simmons and Fitz had to take care of him. Fitz and Simmons then let Johnson with Campbell to give them some privacy. Coulson disclosed his plan to the rest of his team: stealing the warhead containing Hive's pathogen and load it into a Quinjet to have it blown into space, where the pathogen would be harmless. However, this implied that someone had to be in the Quinjet, sacrificing himself. When they discovered that Johnson ran to the Quinjet to do it, Hive and several Primitives appeared, making Fitz and the others fight them.

To everyone's surprise, Campbell had also infiltrated the Quinjet and projected Johnson out of it, taking the Quinjet into the cosmos himself with Hive and his warhead aboard. Johnson begged her friends to bring Campbell back, but Fitz told her that it was impossible, since Campbell had suppressed the remote control and that the Quinjet could not be maneuvered in space anyway. Fitz then watched, helpless, the destruction of the Quinjet, exchanging a saddened look with Simmons at the sight of Johnson, devastated by the loss of his boyfriend.

Sokovia Accords
Six months after the battle at the Playground and Hive's death, S.H.I.E.L.D. had changed: it went public, appointed a new Director to replace Phil Coulson and recruited a lot of new agents like Nathanson. Fitz worked with Jemma Simmons and Holden Radcliffe on a simulation of a working environment known as the Framework, recreating real world spaces like S.H.I.E.L.D. laboratories with an extreme level of details. Fitz also kept working on the development of new weapons of tools for field agents like Phil Coulson or Alphonso Mackenzie, such as an exploding pen.

Yo-Yo's Vendetta
"I'm gonna need your old watch. Upgrading all S.H.I.E.L.D. tech, post-Accords." "Lucky me. Do your thing."

- Leo Fitz and Elena Rodriguez

When Elena Rodriguez came to the Playground in order to sign the Sokovia Accords, she went to the labs where she met with Fitz and Jemma Simmons, who were gently arguing about a television Fitz wanted to buy for their room. While Fitz was setting up her new tracking watch he had specifically designed to account for her Inhuman powers, Rodriguez asked them if they had been looking for a place to live together, much to Fitz's dismay, who told Rodriguez that from this moment Simmons would be obsessed by the matter. He then explained to Rodriguez how the watch worked. Unbeknownst to Fitz and Simmons, Rodriguez had used one of the lab's computer to perform a facial recognition on her target Victor Ramon.

Creation of Aida
"What the hell?!" "Well, you've already met AIDA, digital personal assistant, as a voice on the computer. So, uh, I built her a body." "Yeah, a naked body!"

- Leo Fitz and Holden Radcliffe

Over the weeks, Fitz had developed a friendship with Holden Radcliffe and frequently went at his place to watch football games. During one of these evenings, Fitz accidentally discovered the existence of Aida, a Life-Model Decoy created by Radcliffe in order to serve as his assistant. Fitz showed great discomfort with Radcliffe's project, since he was not supposed to conduct any experimentation without oversight. Radcliffe requested Fitz's help to finish conceiving Aida but Fitz refused, thinking that the best course of actions was to report the existence of Aida to S.H.I.E.L.D authorities. Fitz warned Radcliffe about the dangers that Aida could represent, remembering the mayhem caused by the creation of Ultron. However, Radcliffe and Aida replied that she was not designed as a weapon but as a decoy and a safeguard to prevent Fitz and Simmons to lose more friends after they suffered the losses of Antoine Triplett, Andrew Garner and Lincoln Campbell, for example. Fitz resolved to keep Aida's existence a secret to Simmons and Jeffrey Mace until he and Radcliffe would be sure that she was flawless.

Encountering Ghost Rider
"What are you?" "Yeah. What are you?"

- Frederick and Leo Fitz to Ghost Rider

Fitz and Jemma Simmons were asked to study a mysterious box brought back from a field mission by Phil Coulson and Melinda May. Fitz, not believing that the box was as empty as it looked like, managed to reveal that it contained extremely advanced technology. Alphonso Mackenzie then came to the lab and told them that S.H.I.E.L.D. had heard about someone suffering from the same kind of dementia than the Chinese mobsters who had been in contact with the box. When Mackenzie mentioned the vision of a ghost, Simmons deemed it as simple hallucinations, but then Mackenzie showed them footage of Lucy Bauer, who looked like a spectrum. Fitz and Simmons investigated Bauer's incorporeal nature, mentioning a possible multi-dimensional event like Tobias Ford had experienced. Fitz also studied the composition of the alloy of the box, which was manufactured by Momentum Labs. Upon learning that one Momentum Labs facility was located in Pasadena, California, Mackenzie decided to go on the field to investigate it with Fitz. Fitz and Mackenzie infiltrated the facility and arrived in a mysterious room at the center of which was a strange reactor. However, another incorporeal man, Frederick, appeared, only to vanish when Mackenzie shot at him. Fitz and Mackenzie quickly realized that they were powerless facing such an opponent. Frederick locked Mackenzie in the reactor and threatened to kill him as well as Fitz by blowing up the facility. However, while Frederick was on the verge of killing Fitz, he was stopped by Robbie Reyes, who took his Ghost Rider form to eliminate Frederick. Reyes was followed by Quake, who released Mack out of the reactor. Finally, Fitz managed to stop the reactor, preventing the whole facility to explode.

Miami Blackout
"O.K., all set. Let there be light!"

- Leo Fitz

When Miami was struck by a blackout, Fitz investigated the video sent by the so called "Inhuman Resistance" to determine its origin, seeing that the attack's high level of sophistication excluded the possibility of an opponent acting on his own. Fitz thought that the blackout was caused by an E.M.P. and not by an Inhuman, and warned that this could occur in other cities.

Fitz, Alphonso Mackenzie and Phil Coulson were sent by Jeffrey Mace to Miami in order to solve the crisis. Aboard the Zephyr One, they watched the interview of Senator Ellen Nadeer, who was fiercely hostile towards Inhumans, and were informed that London, Los Angeles and Moscow had also underwent a blackout. Fitz developed a way to track down the origin of the E.M.P. and locate its users. However, since the E.M.P. was continuous and not pulsed, all of S.H.I.E.L.D. modern equipment was out of use when the team arrived in the E.M.P. area, forcing Fitz to track down the E.M.P.'s origin the old way. Fitz, Mackenzie and Coulson then arrived at the hotel where Elena Rodriguez was previously partying with her friends in order to save her from a Watchdogs attack. Fitz, Coulson, Mackenzie and Rodriguez quickly figured out that there was no such thing as the Inhuman Resistance and that all the blackout attacks were set up by the Watchdogs in order to grow hatred towards the Inhumans, since the Watchdogs wanted their extermination. Fitz then crafted hand-made compasses in order to locate the source of the E.M.P.

Fitz, Coulson, Mackenzie and Rodriguez successfully raided the place where the E.M.P. source was located. Using Rodriguez's powers, they unarmed and knocked out all the Watchdogs before deactivating the E.M.P., ending the Miami blackout and giving the solve for other cities. Jeffrey Mace seized this S.H.I.E.L.D. victory as an opportunity to reveal S.H.I.E.L.D. to the public. Fitz watched his press conference with the other S.H.I.E.L.D. agents at the Playground, wondering if going public was such a good idea as he appreciated working in the shadows.

Admitting Aida's Nature
"She's so real. Her... Her conversational responses, her range of motion..." "Those are weird things to say about a person." "Fitz, she's an android. You do know she's an android, right?" "Yeah, of course I know that she's an android, 'cause I helped out."

- Jemma Simmons and Leo Fitz

While Jemma Simmons looked for a place where she and Fitz could live together, Fitz went to Holden Radcliffe's apartment in order to check on Melinda May and work on a chemical cure for the infection induced by Lucy Bauer and her former coworkers. However, he was upset to see that Radcliffe had Aida helping him taking care of May, thus revealing her existence to another person. However, Radcliffe dismissed his fears, stating that May did not notice Aida's android nature. However, Simmons, accompanied by Phil Coulson, came at Radcliffe's apartment as well to greet May for her return to S.H.I.E.L.D. Unlike Coulson, Simmons figured out that Aida was an android and confronted Fitz on the matter. Fitz admitted that he participated in Aida's design and that he did not tell Simmons because she had to undergo frequent lie detector tests. Simmons, distraught, informed Fitz that she had an impending test.

Conflict with Ghosts
"So they're either avoiding the cameras or they've reverted to a halituous state." "Say what?" "A hali... They've gone all ghostly!"

- Leo Fitz and Alphonso Mackenzie

After learning Aida's true nature, Jemma Simmons was mad at Fitz for keeping a secret. Fitz tried to reconcile with Simmons, offering to train her for her lie detection test, but Simmons bluntly refused and sent Fitz away.

Fitz joined Alphonso Mackenzie and Quake on the Zephyr One in order to provide them with antidote syringes for the infections caused by Lucy Bauer and her former coworkers, since they had trapped Phil Coulson and Melinda May in the prison where Eli Morrow was detained. Fitz remained on the Zephyr One to ensure the communications with the team and monitor the prison security feeds so that they could reach Morrow.

When Bauer released some of the prisoners to fight Coulson, Quake and May, Fitz was forced to hack into the prison's systems, thus opening all the doors, including the cells. Fitz then continued to guide his teammates to Morrow through a secure way, though Quake chose to stay behind in order to hold back the prisoners chasing them. Fitz then managed to find another way for Coulson and May to get back to Quake while Mackenzie and Ghost Rider released Morrow. However, the latter was kidnapped by Bauer.

Fitz then took part in other mission at Momentum Labs where they learned that Bauer had taken pieces of equipment in order to replicate the experiment which had turned her into a ghost so that she could reverse the process and abandon her incorporeal nature. Fitz figured out that she needed a more powerful power source to do so.

Fitz needed to access some classified files and needed Coulson's approval to study them. However, Jeffrey Mace, who was aboard the Zephyr One searching for Quake and Ghost Rider, dismissed his request as not being a priority. Ghost Rider, hearing that they had a lead to find his uncle Eli Morrow, forced his way out of the Containment Module, much to Fitz's surprise.

Finally able to access the files he needed, Fitz tracked down the activities of the firm Isodyne Energy, which led him to a Roxxon Corporation facility where Lucy Bauer could produce enough energy to power her experiment. After informing Alphonso Mackenzie of his findings, they flew to the facility. Meantime, Fitz was also worried because no one could tell him where his girlfriend Jemma Simmons, whom he was still having an argument with, was.

Trapped in Hell
"You handed it to a Director who betrayed Simmons! He sent her off, God knows where! We were having an argument, and then she's out there, alone. And I'm gone!"

- Leo Fitz and Phil Coulson

Fitz, Phil Coulson, Melinda May, Alphonso Mackenzie and Robbie Reyes infiltrated Roxxon's power station. However, Fitz and Mackenzie could not cut off the power from the operating room. Mackenzie went back to the Zephyr One to get an E.M.P. device while Fitz remained in the facility. Unfortunately for S.H.I.E.L.D., it turned out that Eli Morrow, who they were trying to save, was the one who was trying to replicate the experiment in order to gain an absolute power. Morrow succeeded, and the reactor he used caused a violent outburst that drove Fitz, Coulson and Ghost Rider in an inter-dimensional space between the Earthly Plane and Hell.

Watching the video footage of what happened at Roxxon's facility, Quake, Melinda May, Alphonso Mackenzie and Jeffrey Mace were puzzled when seeing that Fitz, Phil Coulson and Ghost Rider seemed to have simply vanished. However, unbeknownst to them, Fitz, Ghost Rider and Coulson could hear and see them, but were unable to interact with them.

Fitz, having returned on the Zephyr One, followed Mace after he told the others that he would call Jemma Simmons and inform her about her missing boyfriend. Fitz learnt that Simmons had been taken to an unknown place and that her phone had been confiscated, and that Jeffrey Mace had an arrangement with fiercely hostile to S.H.I.E.L.D. and Inhumans Senator Ellen Nadeer. However, Fitz was distracted by Ghost Rider, who told him that he was freezing and needed heat. Fitz and Coulson then witnessed the transfer of the Spirit of Vengeance from Robbie Reyes to Mackenzie.

Fitz and Coulson returned to the Playground, where May and Mace enlisted the help of Holden Radcliffe and Aida. They noticed that the darkness around them went closer to them, signaling that they were progressively drawn into Hell. Fitz revealed to Coulson that Aida was an android and that she could read the Darkhold in order to find a way to bring them back. Fitz and Coulson argued, since Coulson disapproved Aida's existence but Fitz explained that Aida had been built to prevent further losses like the sacrifice of Lincoln Campbell. Fitz blamed Coulson for resigning as Director of S.H.I.E.L.D, since the new Director had sent his girlfriend in an unknown place and Fitz heavily worried about her. However, Coulson promised him that they would come back and he would be reunited with Simmons. Aida successfully read the Darkhold and built an Inter-Dimensional Gate using Laser-Coupling Gloves built by Radcliffe following the Darkhold's instructions. While she was doing so, Coulson began being dragged into Hell, but Fitz hold him back and finally managed to pull Coulson back from darkness and the two eventually escaped their inter-dimension space and returned on the Earthly Plane. Fitz immediately rushed at Mace to know what had happened to Simmons, who finally returned from her mission of investigating the Terrigenesis of Vijay Nadeer. Fitz, considerably relieved to see that Simmons was safe, hugged her, finally having a tender moment with her after their argument about Aida's conception.

Battle at the Chinatown Crew Headquarters
"So what is the cause of the quake?" "Grand larceny."

- Quake and Leo Fitz

Fitz and Jemma Simmons assisted the rest of the team from the Zephyr One when an assault was launched against the Chinatown Crew Headquarters in order to stop Eli Morrow. They also monitored the numerous earthquakes that were happening across the globe. When Ghost Rider infiltrated the building, Fitz discovered that Morrow had built a giant Quantum Battery. Morrow placed a Demon Core (a subcritical mass of plutonium) inside the Battery, making him able to cause a massive nuclear explosion.

While talking with Quake, Fitz and Simmons found out that Morrow was at the epicenter of a new earthquake that Quake was feeling. Fitz then understood that Morrow was not creating matter out of nothing, but rather was harvesting energy from another dimension, which caused all the earthquakes. Fitz, Simmons, Holden Radcliffe and Aida went under the Chinatown Crew Headquarters, building a new Inter-Dimensional Gate in order to end Morrow's plans while Quake absorbed the sismic waves. They were discovered by one of Morrow's mobsters, who shot Aida before being killed by Fitz and Simmons. Despite this interruption, S.H.I.E.L.D.'s plan succeeded and Morrow was sent to another dimension along with Ghost Rider and the Quantum Battery.

Fitz and the rest of the team returned to the Playground, where they watched the news talking about the S.H.I.E.L.D. operation in Los Angeles.

Aida's Betrayal
"Fear, anger... They're powerful feelings. Feelings that make people kill, so can you imagine being bombarded with them all at once? When we've had our whole lives to process complex emotions, Aida would've had days. It would be overwhelming"

- Leo Fitz to Holden Radcliffe

While S.H.I.E.L.D. intended to dispose of the Darkhold, Fitz was sent to Holden Radcliffe's apartment with two other S.H.I.E.L.D. agents in order to erase Aida's memory, since she had read the Darkhold. However, Aida, who had secretly upgraded herself, refused to comply and rebelled, knocking out Radcliffe and the S.H.I.E.L.D. agents before assaulting Fitz, who found the dead body of Nathanson. Following Aida's departure, Fitz and Radcliffe went back to the Playground were they were bitterly greeted by Alphonso Mackenzie, who had warned them against the threats that robots and androids represent. Fitz and Simmons told Phil Coulson and Melinda May's LMD (who had replaced the real Melinda May unbeknownst to S.H.I.E.L.D.) that the Darkhold was likely responsible for Aida's rebellion. Aida, who had taken control over all of her systems, called S.H.I.E.L.D. agents at the Playground, including Fitz, and demanded to be given the Darkhold. When Coulson refused, Aida hacked into S.H.I.E.L.D. systems and cut the power. Fitz and Radcliffe went to the servers room in order to keep Aida out of the Playground. However, Aida had already entered the base and retrieved the Darkhold. Fortunately, Mackenzie beheaded her with his Shotgun-Axe before she could leave the Playground, much to Fitz's horror. Though she was destroyed, Fitz reclaimed Aida's head. Fitz visited Radcliffe and advised him to stay away from S.H.I.E.L.D. for a few days. He also intended to work on Aida's head to find the cause of her malfunctions. However, Simmons disagreed with this project, wanting the head to be destroyed, and asked Fitz to forget about it.

Conflict with the Watchdogs
"Were not idiots. We took the bad stuff out. Most of it, anyway." "Oh, O.K. So you're just mostly idiots."

- Glenn Talbot and Leo Fitz

When the Watchdogs tried to assassinate Director Jeffrey Mace, Fitz and Jemma Simmons helped S.H.I.E.L.D. to find him as well as Phil Coulson and Alphonso Mackenzie, who had gone missing as well. However, he and Simmons soon learned a disturbing truth from General Glenn Talbot : contrary to what had been announced, Mace was not an Inhuman. Instead, he was using a super strength super-serum inspired from Calvin Zabo's Formula.

Fitz and Simmons strongly disagreed with this decision, stating that despite the precautions taken, the super-serum could be dangerous for Mace's health. Since they could not locate the Quinjet used by Mace due to a jamming system, Fitz and Simmons suggested to use Aida's severed head in order to intimidate Yuri Zaikin, the Watchdog who had tried to kill Mace, to find their missing colleagues. The idea proved to be successful. Despite Simmons's disagreement, Fitz resolved to study Aida's head to find what had caused her rebellion. He downloaded her data on his phone and told Simmons that the head was locked in a S.H.I.E.L.D. vault.

Discovering Radcliffe's Betrayal
"I wanted to help you get through this obsession of yours but if you continue to..." "It's not an obsession! Jemma, it's an investigation."

- Jemma Simmons and Leo Fitz

Fitz kept looking for the cause of Aida's betrayal. Melinda May went to see him, since she was also looking for answers regarding Aida. Jemma Simmons saw that her boyfriend seemed troubled and offered to discuss, but Fitz told her that she had nothing to worry about. However, after S.H.I.E.L.D.'s failed attempt to infiltrate Senator Ellen Nadeer's office and get some information on her, Simmons and May figured out that the Senator had intel from inside S.H.I.E.L.D. Simmons understood that Fitz had been working on Aida's head all along instead of locking it for good. Simmons accused Fitz of being the source of Nadeer's intel since he could have turned on Aida's eye camera and thus leaked intel from within S.H.I.E.L.D. However, Fitz rejected Simmons' accusations and corrected her when she told him he was obsessed with Aida. Instead, Fitz told her that he had been investigating on the cause of Aida's malfunction and that he had found the answer : Holden Radcliffe, Aida's creator. Following this revelation, Fitz joined a team of S.H.I.E.L.D. agents led by Phil Coulson to Radcliffe Residence in order to arrest Radcliffe. Radcliffe was locked in a Containment Module at the Playground, where Fitz visited him. Fitz confronted Radcliffe about his betrayal and blamed him for having programmed Aida the way he had. Then, Fitz figured out that he was not talking to the real Holden Radcliffe but rather to a Life-Model Decoy. Fitz took the gun of the agent guarding Radcliffe's module and shot the android, revealing the trickery. Fitz repaired Radcliffe's LMD and interrogated him in order to find out where the real Radcliffe was and what his plans were. Since Radcliffe's LMD proved to be uncooperative, Fitz decided to hack into his systems to find the answers. However, the android's programming was incredibly complex and Fitz was unable to access it. The longer the questioning lasted, the more troubled FItz was, especially when Radcliffe's LMD mentioned Fitz's father. Indeed, the android assumed that Holden Radcliffe and Alistair Fitz were classmates and that Radcliffe knew how few consideration Alistair had for his son. Fitz, enraged when reminded of his abusive father, disconnected the android and left the labs.

Back in his bedroom, where he stared at an old picture of his mother and him, Fitz was joined by Jemma Simmons. Fitz lamented over the fact that he had been betrayed on multiple occasions, be it by his father, Grant Ward or Radcliffe. However, his girlfriend made him see the bright side by reminding him that these betrayals had not kept him from becoming a good and caring person. When Fitz noticed that this could be the reason why he kept being betrayed, Simmons replied that it was the reason she fell in love with him. Finally, when Simmons told Fitz that his personality was something more than pure programming, it clicked in Fitz's mind : if he could not crack Radcliffe's LMD's code, it was because the android was not running on pure programming as well. Instead, he was using a Quantum Brain built by Aida thanks to the knowledge of the Darkhold. While Fitz and Simmons examined his Quantum Brain, Radcliffe's LMD inadvertently revealed that Holden Radcliffe and Aida had crafted more than one Quantum Brain : the Melinda May that had been with them in the last few days was also a LMD. Fitz and Simmons thus informed Daisy Johnson, who was on the field with Melinda May's LMD, who was closer than ever to retrieve the Darkhold.

Finally, considering that they had obtained all the answers that they could get, Fitz, Simmons, Alphonso Mackenzie, Quake and Phil Coulson proceeded to the destruction of Aida's severed head and Radcliffe's LMD in a furnace.

Fighting Tucker Shockley
"Don't do that!" "What, help save the day?" "No, do that. Just don't risk your life when you're doing it! You could've been blown to bits."

- Jemma Simmons and Leo Fitz

Fitz learned the death of Senator Ellen Nadeer, whose office had been destroyed by a violent explosion. He then accompanied Director Jeffrey Mace, along with Daisy Johnson and Jemma Simmons, to the Capitol in order to investigate the remnants of the Senator's office. Together, they found out that the Watchdog Tucker Shockley visited Nadeer prior to the explosion, making him a suspect in S.H.I.E.L.D.'s eyes.

Fitz went back to the Zephyr One, where Shockley was brought following his capture by Johnson. After performing numerous analysis, he and Simmons figured out that the explosion had not been caused by a classical bomb but by an Inhuman who had underwent Terrigenesis : Shockley himself. Fitz, with the assistance of Mace and Simmons, managed to place Shockley in the Zephyr One's Containment Module and eject it out of the plane right before another deadly explosion, saving the lives of everyone on board. Fitz and Simmons understood the mechanism of Shockley's explosions and requested Johnson's help since her powers could be used to defuse Shockley's explosions. Fitz designed a containment sphere in which S.H.I.E.L.D. managed to imprison Shockley and contain his explosions. However, they lost Director Mace to the Watchdogs and their leader Anton Ivanov on the mission.

Krasnoyarsk Krai Battle
"You do need to think about the implications of the things you create. But just because someone uses your ideas for evil does not make it your fault for creating it in the first place. You make things from the genius of your mind and the goodness of your heart to help people. Don't let Radcliffe's actions corrupt that. You are not responsible for the twisted things he's done. Wrongs have been committed. Now we make them right... together."

- Jemma Simmons to Leo Fitz

Fitz introduced his version of the Framework to S.H.I.E.L.D. agents, describing it as an virtual area where they could train and practice with an extreme level of sensations and detail. Fitz and Simmons then explained to Phil Coulson, Daisy Johnson and Alphonso Mackenzie that Aida and Holden Radcliffe had built another version of the Framework in which Melinda May was trapped.

Mackenzie was very critical towards the Framework and voiced his critic to Fitz, reminding him that many of the ordeals S.H.I.E.L.D. had to overcome in the recent days was a more or less direct consequence of Fitz's designs. Fitz rejected these accusations, saying that he merely had conceived tools and that he could not be blamed if misguided people like Radcliffe were using it the wrong way.

Finding the location of Radcliffe's Framework proved to be hard. Fitz quickly figured out that thanks to the power of the Darkhold, Aida and Radcliffe had built an extremely wide version of the Framework which connected at every server around the globe, making it very difficult to track. However, Coulson ordered Fitz to carry on his efforts, since they could not afford to lose May and Mace.

Mackenzie's accusations deeply affected Fitz. Upon learning that S.H.I.E.L.D. was heading to Krasnoyarsk Krai where May and Mace were likely detained, Fitz was worried that May could suffer heavy damage due to her time spent in the Framework. However, he found comfort beside his girlfriend Jemma Simmons who reminded him that he never had bad intentions and that he had a chance to make amends for his mistakes by rescuing his friends.

Fitz, Simmons, Coulson, Mackenzie and Johnson infiltrated Krasnoyarsk Krai's naval base, where he and Simmons had to take over the communications room. Upon finding some old computer equipment, Fitz decided to copy the data and try to find some Framework hardware while Simmons went to find Aida who had been spotted in the base. However, Fitz was captured by Anton Ivanov's men. His memories were downloaded and uploaded in a Life-Modey Decoy while his real body was forcefully connected to the Framework by Aida, alongside with those of May, Coulson, Mace and Mackenzie.

The Framework
Following his connection to the Framework, Fitz's memories were replaced by a whole new virtual life. In the Framework, Fitz became a ruthless high-ranking officer of HYDRA nicknamed The Doctor, making the pride of his father who had imprinted his cruel and cold nature in his son's mind. Fitz never knew Jemma Simmons in this world, less did he fall in love with her, and was instead Aida's lover, the android being known as Madame Hydra, leader of the organization which had taken control over the world after S.H.I.E.L.D.'s demise, and whom Fitz remembered to have met during his time at the S.H.I.E.L.D. Academy.

Hunting Subversives
"You know, my father always said you have to have trust to be betrayed. Treat this mole like a cancer." "I'll cut it out myself." "Well, you failed before. Never forget how it felt at Cambridge."

- The Doctor and Melinda May

When Daisy Johnson, who had infiltrated the Framework (where she goes under the alias Skye) in order to rescue her friends, lost control of Vijay Nadeer, she encountered the Doctor. Once Nadeer was back in HYDRA's custody, The Doctor showed Skye the machine he designed in order to test the presence of Inhuman powers without inducing Terrigenesis, showing no consideration for the pain suffered by the subject, much to Skye's dismay. When Skye voiced her concerns about the fact that The Doctor's machine was completely immoral, The Doctor dismissed her critics. Their conversation was interrupted by the arrival of Melinda May, who informed him of the reporting of Jemma Simmons as a subversive by Phil Coulson. The Doctor ordered May to send a team to arrest Simmons. However, the mission failed and The Doctor learned from May that a mole was likely working from within HYDRA. The Doctor, reminding May of what happened during the Cambridge Incident, ordered May to eliminate the traitor. Later, Fitz visited Madame Hydra in her office. They discussed the presence of dangerous subversives before sharing a kiss. The Doctor visited Madame Hydra once again, asking her why she did not wanted him to take part in the chase of Jemma Simmons. Madame Hydra reluctantly showed him the picture of Simmons and The Doctor, after staring a long time at a picture of Simmons, decided to take the lead on the chase. Before leaving, The Doctor once again confessed his love for Madame Hydra, saying that he would cross the universe for her, possibly unconsciously referring to an event which occurred in the real world, and the two shared a passionate kiss. Afterwards, in order to arrest Simmons, The Doctor summoned Melinda May and Daisy Johnson and put them in charge of the mission.

Feeling that Madame Hydra had been keeping information about Simmons, The Doctor infiltrated her office and found out that the alleged subversive was officially deceased. Madame Hydra then revealed The Doctor that Simmons did not belong to their world and that she was here to destroy everything they had built inside the Framework. The Doctor learned that in this other world, S.H.I.E.L.D. had defeated HYDRA. Madame Hydra told her lover that she was a slave in this world and that she needed him to complete his Project Looking Glass so that she could defeat her enemies once and for all. When Madame Hydra left her office asking him to follow her, The Doctor stared once again at Simmons's picture, seemingly troubled.

Executing Agnes Kitsworth
"I guess you don't know me at all."

- The Doctor to Daisy Johnson

Madame Hydra took The Doctor to Ogygia, an island of the Framework designed as a residence for Holden Radcliffe and Agnes Kitsworth, since HYDRA had received an alert indicating the presence of S.H.I.E.L.D. agents. Though The Doctor could not find Grant Ward, Phil Coulson or Jemma Simmons, who where on the island, he found Kitsworth and could not help but notice her resemblance to Madame Hydra. Panicking, Radcliffe explained to The Doctor that Kitsworth was not a threat to HYDRA. The Doctor, disbelieving Radcliffe, threatened Kitsworth with the gun of a HYDRA agent. Radcliffe tried to have Fitz remember some memories of his life in the real world, mentioning his love story with Simmons and how he had risked his life to save her when they were in the bottom of the ocean and when she was trapped on Maveth. However, The Doctor chose to believe the version of his lover, who told him that everything told by Radcliffe was a lie, and shot Kitsworth, killing her. This cold-blood murder horrified Simmons, who witnessed the whole scene and screamed, and The Doctor stared at her, puzzled, while his agents exchanged bullets with Coulson and Ward. The Doctor then left Ogygia. Back at the Triskelion, The Doctor visited Daisy Johnson, who had been captured by HYDRA after having been tricked to admit her allegiance to S.H.I.E.L.D.. Ignoring her pleas about him being trapped in an alternate reality like Radcliffe had said before, The Doctor informed her that they knew she was an Inhuman and called two guards to take Johnson out for questioning and torturing her, stating that Johnson did not know him.

Countering S.H.I.E.L.D.’s Assaults
"This is my home. I’m not gonna let you destroy it. We’ll get to yours first."

- The Doctor to Daisy Johnson

The Doctor further interrogated Daisy Johnson in her cell, asking her to reveal the whereabouts of the Patriot and of Jemma Simmons. He also told her that he was aware of the existence of another world from which Johnson had come and that HYDRA considered that Johnson and Simmons had entered the Framework to conquer it. Johnson replied that she did not know where Mace and Simmons were but that she would gladly give him the location of Simmons if she knew it since she considered her to be the only person to make Fitz realize that his life in the Framework was an immense lie. Enraged, The Doctor violently slapped Johnson, calling the Framework his home.

The Doctor reported the results of his unsuccessful interrogation to Madame Hydra, who decided to carry on the questioning while The Doctor had to deal with a security breach regarding the Project Looking Glass, due to S.H.I.E.L.D. agent Antoine Triplett having placed a camera in a HYDRA facility. The Doctor then walked and discussed with his father Alistair Fitz, expressing concerns about the necessity of killing Agnes Kitsworth. However, his father dismissed this feelings as being nothing more than womanly and unworthy of him, to which The Doctor agreed.

When S.H.I.E.L.D. assaulted an HYDRA Enlightenment Cultivation Center, Melinda May informed The Doctor, who injected her with a dose of super-serum in order to lead a team of HYDRA agents. He then joined Madame Hydra in her office and ordered the destruction of the quarantine building where the Patriot had gone. Together with Alistair Fitz, they later celebrated the death of the S.H.I.E.L.D. leader.

Completing Project Looking Glass
"It’s done, Ophelia. I’ve completed the design. You won’t have to live like this for much longer. I had my doubts about the project but I finally see it. Your new body will be stronger. That’s who you were meant to be. I just have one request : take me with you."

- The Doctor to Madame Hydra

The Doctor was devastated after Melinda May and Daisy Johnson’s escape during which Madame Hydra was severely injured. Alistair Fitz told him that he was now acting leader of HYDRA. As such, The Doctor summoned Sunil Bakshi to the Triskelion and ordered him to disclose the identity of the two rebels on his T.V. show. He was later informed by his father that HYDRA had received a tip regarding the location of the S.H.I.E.L.D. agents responsible of his lover’s situation. When The Doctor decided to lead the chase himself, Madame Hydra woke up and ordered him to complete the Project Looking Glass as it was the only way of saving her, and thus let his father lead the operation. However, the HYDRA mission failed to capture the S.H.I.E.L.D. agents. The Doctor, enraged, yelled at his father for this failure but was quicky chastized in return, with Alistair Fitz considering his reaction to be only worthy of his mother. The Doctor calmed down and admitted that he could not tolerate any weakness or failure, even from his father. He later went back to Madame Hydra’s apartment and informed her that he had completed his Project Looking Glass, enabling her to get a new and stronger body. The Doctor also asked his lover to take him with her. Later, Alistair Fitz informed him that after interrogating Holden Radcliffe, he found out that the fallen scientist and Daisy Johnson had been communicating through the vent between their respective cells.

Leader of HYDRA
"Look at him. Look at him! That's my father lying there, murdered in the home that I bought for him.You're gonna lead me to Jemma Simmons, where it is my intent to put a bullet through her skull!"

- Leopold Fitz to Holden Radcliffe

The Doctor went to Holden Radcliffe's cell in order to determine what the he and Daisy Johnson discussed when they were both imprisoned in adjacent cells at the Triskelion. At first, Radcliffe refused to speak, telling that he was already dead in the real world and that living in such a horrible version of the Framework, without Agnes Kitsworth, meant nothing to him. However, The Doctor persuaded Radcliffe to change his opinion by telling him that his Project Looking Glass could enable the transhumanist scientist to achieve immortality. The Doctor thus learned of the existence of the backdoor and gathered a team of HYDRA agents to stop Jemma Simmons and Quake. However, while the Zephyr One was heading to the steel mill indicated by Radcliffe, The Doctor received a phone call from his father Alistair Fitz. Indeed, his father was threatened by Simmons who ordered him to bring Fitz, but instead he chose to ask his son to come and arrest Simmons. The Doctor heard his father being accidentally killed by Simmons and rushed at his house, only to find his dead body. Enraged, The Doctor had Radcliffe staring at the body of Alistair and swore to get revenge on Simmons. Despite Madame Hydra ordering him to get back to the Triskelion, The Doctor took the Zephyr One and the HYDRA team to the steel mill where the S.H.I.E.L.D. agents were. Accompanied by Radcliffe, The Doctor found Simmons and ordered her to kneel before him and acknowledge that she meant nothing to him in the Framework. Simmons refused, which ended up in the Doctor shooting her in the leg to force her to kneel. While he was on the verge of killing her, however, Radcliffe turned against him and disarmed him. Indeed, Radcliffe had gained The Doctor's trust to bring him to the backdoor and save Fitz, seeking to make amends for his past mistakes. Fitz was thus successfully brought back into the real world.

Escaping the Framework
"No, no, but I've... I've killed people!" "No! They weren't real!" "Agnes was real. And M-Mace. I ordered the air strike that killed Director Mace."

- Leo Fitz and Phil Coulson

Fitz woke up in Anton Ivanov's naval base, where Phil Coulson and Melinda May were already awake. However, when remembering that his actions had led to the deaths of Agnes Kitsworth and Jeffrey Mace, Fitz was horrified and started panicking, despite Coulson trying to calm him down. While Fitz was still in distress, Aida arrived, using her newly created human body. She smiled at Fitz and seemingly tried to seduce him like she did in the Framework. Fitz, puzzled, was unable to react and could not move away, keeping May from shooting Aida. Suddenly, Aida teleported, displaying an ability similar to the Inhuman Gordon and took Fitz away with her.

Aida's Madness
"You understand that my love will never fade." "No, I know. Poor thing. You're a romantic. And there's only room in your heart..." "... for her." "What?"

- Leo Fitz and Aida

Aida teleported Fitz and herself to a beach, where she experienced the pleasant sensations of the warm sand and the water on her feet. Fitz himself was not that well, torn between his real life and his memories of the Framework. He confronted Aida about manipulating him and causing pain. Aida said that she had only repaired his relationship with his father and confessed that she loved him. Afterwards, she teleported with him into an apartment. Though the apartment was made so that Fitz would find it familiar, Fitz was still highly troubled. Fitz asked Aida if she was able to feel empathy and made her realize that by carrying her plans, she had endangered the lives of the other S.H.I.E.L.D. agents by enabling Anton Ivanov to kill them. Upon understanding that and by using her newly found compassion, Aida teleported back to the naval base and tried to stop Ivanov's multiple mechanical bodies who had taken over the base. Aida successfully returned to the base with Fitz and saved Alphonso Mackenzie, who was still trapped in the Framework. They teleported on the Zephyr One, where Piper and Jemma Simmons used I.C.E.R.s on them and locked them into the plane's Containment Module. The whole team, finally reunited, headed to the destroyed Playground, where Fitz and Aida were placed in one of the remaining Containment Chamber, blocking Aida's teleporting abilities.

Fitz finally woke up and discussed with Aida. He lamented over the fact that his friends would not forgive his past actions in the Framework. Still traumatized by his behavior as The Doctor, Fitz thought that he had an evil nature implanted by a father figure, just like his former colleague and friend Grant Ward, and feared that this would drive Simmons away from him, destroying all the future he had planned for their couple. Aida tried to comfort him but mistakenly thought that after what they had experienced in the Framework, Fitz was still in love with her in the real world. When she realized that Fitz was still deeply in love with Simmons and only her, Aida went completely insane.

Aida tried to forcefully take Fitz out of the Playground to live with him, whether he wanted it or not. However, due to the Quantum Field Disruptors of the chamber, Aida could not escape. Fitz was pulled out of the chamber by Davis, Piper and Prince. Fitz warned them that Aida would easily leave the Containment Chamber: indeed, she had built a body with numerous Inhuman abilities, including Lincoln Campbell's lightning manipulation. They were later caught by soldiers sent by Glenn Talbot and immediately after, Aida attacked them. Prince was killed but Piper managed to bring Fitz to the Zephyr One, where he ordered May to take off the plane, as they were no more than easy targets for Aida. Talbot agreed to let the S.H.I.E.L.D. agents leave and they finally escaped the ruins of the Playground.

Fitz remained in the plane's Containment Module, grieving about what happened. He was joined by Simmons who, after hesitating, sat beside him and hugged him in comfort. Both of them burst into tears, traumatized but finally reunited.

Regrets and Guilt
"This is not on you. We all lost ourselves in there. And yeah, it might take you a long time to forgive yourself. But speaking on behalf of the team: you have nothing to apologize for." "If there's a price to pay, we pay it. Together." "Amen."

- Daisy Johnson, Melinda May and Jemma Simmons to Leo Fitz

Since S.H.I.E.L.D. was heavily vulnerable to Aida's assaults, Fitz and Jemma Simmons tried to figure out a way to stop her. Fitz told Simmons about the Inhumans he had been studying in the Framework, assessing their powers through painful and even lethal procedures, which included Lincoln Campbell, Vijay Nadeer and Gordon. Fitz lamented over the fact that he was unable to find an efficient solution to stop Aida and that his ideas had only brought pain and death so far. Simmons replied that this was the kind of idea they needed because Aida had to be killed, though Fitz did not seem enchanted by this perspective.

The S.H.I.E.L.D. agents soon had to deal with another part of Aida's plans. Indeed, Aida was shutting down the Framework, deleting all the elements in it and thus threatening the lives of Alphonso Mackenzie and Elena Rodriguez who were still trapped in it. Fitz and Daisy Johnson managed to find a way to postpone their deletion, but it would only last a few hours. When S.H.I.E.L.D. finally retrieved the Darkhold from Aida with assistance of Ghost Rider, Phil Coulson devised a plan to lure Aida and stop her. In order to complete this plan, he asked Fitz and Simmons to put aside their emotional troubles about what had happened in the Framework in order to work together. Fitz and Simmons silently nodded, ready to work together. Fitz returned at the Playground with the others and he and Simmons were quickly confronted by Aida, who seized Simmons and threatened to kill her. Fitz, distressed, agreed to help Aida retrieve the Darkhold and come with her, but Aida stabbed Simmons nonetheless much to Fitz's horror. However, unbeknownst to Aida, Simmons had been replaced by a Life-Model Decoy in order to lure Aida into a trap, and Fitz, though visibly shaken, had only fooled Aida by making her believe he would obey her. Fitz then rushed at the real Simmons and the two of them watched as Coulson, temporarily using the powers of the Spirit of Vengeance, destroyed Aida's body while she was staring at Fitz in despair.

With Aida gone, Fitz attended Robbie Reyes' return to Hell. Shortly after, Mackenzie and Rodriguez, who had escaped the Framework, warned them about incoming soldiers who intended to arrest all the S.H.I.E.L.D. agents. Still feeling guilty about all that happened since he had been highly involved in both Aida's and the Framework's design, Fitz offered to take the blame for all the team, remaining at the Playground while the others left. However, his friends refused, with Daisy explaining that she had tried to do something similar after Lincoln Campbell's sacrifice, only for her to lose herself and realize she needed her friends. Crying but relieved that his friends had forgiven him, Fitz joined them as Coulson took his colleagues to a diner where they happily enjoyed a meal, finally reunited. Shortly after, however, a mysterious man leading a squad cut the power and kidnapped everyone but Fitz.

Arrest and Escape
"It's good to see you."

- Fitz to Lance Hunter

Fitz had little time to cope with the fact that his friends had gone missing as the military, led by Evans and Lucas, came to arrest him and took him to the Blue Raven Ridge facility. There, Fitz was interrogated because he was suspected of having helped the other S.H.I.E.L.D. agents to escape. Fitz denied all the accusations but acknowledged that he was responsible for the death of Jeffrey Mace. He then offered to fully cooperate in order to locate the other S.H.I.E.L.D. agents, being provided books to elaborate multiple theories. However, over the course of six months, none of them proved to be relevant and General Hale grew wary of Fitz's failed attempts. While looking for his friends, Fitz had also tried to reach his friend and former S.H.I.E.L.D. coworker Lance Hunter through fan letters sent to a football magazine. Hunter eventually got Fitz's message and came to him at the facility. After an emotional reunion, Hunter helped Fitz escape the military and both started looking for their missing friends. Fitz accessed the security camera footage and identified the vehicle used by Enoch and his squad when they arrested the team. After tracking down the vehicle, Fitz and Hunter discovered where Enoch was living.

Confronting Enoch and the Hintons
"He'd like to know why he's not with his friends. Can you tell Fitz? He'd really like to know why he's not with them." "'Cause you have to save them."

- Polly Hinton and Robin Hinton to Leo Fitz

Fitz and Lance Hunter journeyed to Enoch's house and, much to their surprise, discovered that Enoch was expecting them. Enoch told them that he had sent the team to the future to help fulfilling a prophecy but as Fitz was not part of it, he was not taken with the others. Angered, Fitz seized Hunter's gun and ordered Enoch to take him to whoever had made the prophecy.

It turned out that the seer was none other than Robin Hinton, the daughter of Charles Hinton who had been involved in S.H.I.E.L.D.'s activities during the Inhuman Outbreak. Fitz, Hunter and Enoch went to find her and her mother Hinton, but before they had time to further investigate, Evans and Lucas found them, forcing everyone to flee thanks to Enoch.

Enoch led Fitz and the others to what would be later labeled as the Lighthouse. There, Fitz confessed to Hunter that he still worried about his potential evil nature and that maybe the universe was trying to protect Jemma Simmons by keeping Fitz and her from living their love story. Hunter rejected his theory, stating that Fitz and Simmons were meant to be together and that if he wanted to know why he was taken with the rest of the team, all he had to do was asking Robin. Fitz did so and Robin simply answered that Fitz had been left behind because he was meant to save his friends, handing him over a drawing with a worrying prophecy.

To the Future
"I love you." "I know."

- Lance Hunter and Leo Fitz

As Fitz was from this moment part of Robin Hinton's prophecy, Enoch agreed to help him find his friends in the future. Enoch told Fitz about the capsule he used to come to Earth which had been reclaimed by the military and stored in the very same facility Fitz was imprisoned earlier. Despite Lance Hunter's reluctance, Fitz and Hunter drove back to the facility and managed to retrieve the capsule, as well as the Zephyr One that they used to escape.

The capsule turned out to be a cryofreeze chamber that Fitz used to be put into stasis for 74 years after an emotional goodbye with Hunter.

2091
"We have a few days before we arrive at the Lighthouse, that should give me enough time to prepare you." "Prepare me for what?" "For facing off against some of the most ruthless and brutal mobsters, monsters, and mercenaries in the galaxy."

- Enoch and Fitz

After all the S.H.I.E.L.D. team but Fitz appeared in the year 2091, they retrieved an old postcard on Virgil's body, with an handwritten message from Fitz saying that he was "working on it".

Fitz eventually woke up from his cryo-sleep to Enoch, who had been waiting for him over the entire 74 years. Enoch then teased Fitz's upcoming mission to save his friends, and then said it was time to begin his training.

Later, as Kasius was on the verge of opening a demonstration of Inhumans' powers for his potential customers so that Quake could show her potential, Fitz intervened, revealing his presence on the Lighthouse, and declared that Quake should fight to the death.

Helping Friends
"I'm never leaving you again." "Then marry me, Fitz." "Absolutely."

- Leo Fitz and Jemma Simmons

After Kasius's inaugural speech, Enoch told Fitz about the other attendees and about how they all viewed him as a formidable Marauder known as Boshtok. Fitz then saw Jemma Simmons and walked over to her while she turned his back to him. After telling her to pretend she did not hear him, Fitz once again confessed his love for her and eventually proposed to her. However, Fitz figured out that Simmons could not hear him and asked Kasius about the reason, prompting Kasius to turn off Simmons' hearing implant.

Later, Fitz had dinner with Kasius and the rest of the potential bidders, where he engaged in conversation with several of the participants in the demonstration. Fitz impressed Kasius with his comments, and declined the offer of eating a Xandarian Snail. During the dinner, Fitz eyed Simmons, where she showed him discretely that she had taken a knife from the table. After the dinner, the fight began and Kasius escorted the bidders into an overlook, where Kasius and Fitz sat next to each other. Kasius then announced the first fight, which was between Ben and Melinda May. During the fight, Fitz and Kasius talked about their difficult relationships with their respective fathers. As May had trouble fighting Ben, Fitz exclaimed that he was bored and demanded to see The Destroyer of Worlds fight. Kasius assured him it would happen, and Fitz told Kasius to send May to the surface, which he complied.

After the first fight, Fitz returned to the hall, where it was assumed the bidding would begin on Ben. However, Kasius revealed that he knew Ben had previously lied to him, which was punishable by death. Despite Fitz's and Daisy Johnson's protest, Kasius had Sinara kill Ben. Later, down a hallway, Fitz saw Simmons, where she stopped to stare at him. Fitz was about to approach her, when another one of Kasius' servant girls walked over to Simmons and told her to go with her. Enoch in turn approached Fitz and told him that Kasius' brother Faulnak had come to the demonstration to bid on Johnson, which endangered their plan of purchasing her. Fitz attended the second fight: Johnson versus Sinara. Sinara was ultimately defeated and Fitz seized this opportunity to punch Gaius Ponarian in his face and disable the barrier between the arena and the gallery, then pointing the weapon and the others in the room. Simmons had launched forward during this and cut Kasius' left cheek. Daisy then launched herself up, using her powers, and prepared to attack Faulnak, when he disabled her abilities and she went crashing to the floor. Moving forward, Fitz saw this and began shooting at the bidders and jumped into the arena, reactivating the barrier in the process to keep the bidders from following him. Finally fully reunited with Simmons, the two shared a passionate kiss and Simmons asked Fitz to marry her, to which Fitz immediately and fully agreed. Fitz, Simmons and Johnson then left the Arena, after Fitz shot Sinara and another Kree guard.

To The Surface
"I don't know about you, but I could really use a drink right about now." "I'm just happy for some alone time."

- Jemma Simmons and Leo Fitz

Fitz, Jemma Simmons and Quake made their way through Kasius' Suites until Simmons had to stop due to the Kree messing with her ear implant. Fitz managed to extract it while Quake took down a Kree guard. Fitz intended to take his friends to the Chronicom Vessel he had used to come to the Lighthouse, but the spaceship was destroyed by the Kree, leaving them with no escape. They reached an elevator, hoping to find the rest of the S.H.I.E.L.D. team, but the elevator was stopped by Maston-Dar, forcing them to escape through the elevator shaft.

They arrived in the room where the artificial gravity of the Lighthouse was created with Gravitonium when Maston-Dar found them and shot Fitz with his machine gun, wounding him. They still managed to escape after Quake briefly fought Maston-Dar. Hiding elsewhere in the Lighthouse, they were found once again, this time by Deke. While Quake and Deke argued about the latter's betrayal, Simmons tended to Fitz's wounds. The S.H.I.E.L.D. agents then reluctantly agreed to follow Deke. Together, they fled to the Salvage, where Fitz was reunited with the rest of his friends, much to their enjoyment. After rescuing Flint from the Kree Watch, they were surrounded by Kree led by Maston-Dar and Sinara and figured out that the only place to go was the surface of the Earth.

Fitz and the others used Deke's Gravity Puck to create a gravity well to reach the Trawler. However, Alphonso Mackenzie, Yo-Yo Rodriguez and Flint decided to remain behind to protect the inhabitants of the Lighthouse. Thus, Fitz told them about the secret cache where he had stored some S.H.I.E.L.D. weapons before entering cryo-sleep. Fitz and Simmons sat together in the Trawler and expressed their desire to have some peaceful time alone.

Reunion with Robin Hinton
"To me, Robin was a little girl only days ago."

- Leo Fitz

After the Trawler crashed onto the surface of the Earth, Fitz and the others were rescued by the True Believers who took them to the remnants of the Zephyr One, and Fitz was amazed to see that his designs had endured time so well. Fitz and Jemma Simmons met with a now elderly Robin Hinton and tried to get answers from her, but to no avail as Robin still had a hard time distinguish the different times. They went to explore the plane further and found a strange mechanism and Samuel Voss told them that it had been built by Owen Shaw to bring the S.H.I.E.L.D. agents from the past. Fitz and Simmons remained alone in the room and finally enjoyed some privacy together. Later, while Fitz and Simmons were examining Daisy Johnson to determine whether they could remove her Inhuman Control Device, Phil Coulson and Melinda May revealed that they had found a fragment of the White Monolith. Fitz figured out that the piece fitted into the strange mechanism they had found and they decided to ask Robin about the whereabouts of other fragments. Fitz and Simmons studied the mechanism further and when Fitz tried to get out to report their findings to the others, he discovered that the door had been locked. Indeed, the True Believers had turned against them and intended to keep them from returning in the past, believing that by doing so Quake would not destroy the Earth. S.H.I.E.L.D. managed to defeat the True Believers, but Robin was killed by Voss during the fight, leaving them with less answers than ever. They mourned their loss and May told them that Robin had told her the key to their return in their time: Flint.

Upgraded Zephyr One
"That's a bad idea, right? Could that actually work?" "Assuming we don't get crushed by debris..." "...slammed back to the ground..." "...or our thrusters don't run out of power..." "...and spin out into the void, we're in!"

- Deke Shaw, Leo Fitz and Jemma Simmons

As a gravity storm was coming, Fitz and Jemma Simmons worked on repairing the Zephyr One with the intent of flying it back to the Lighthouse. However, the task proved to be difficult as the plane was damaged and had not been used for years. Fitz and Simmons discovered that the Zephyr One had been modified by Fitz's designs he never had the chance to put into practice and they found what was powering the plane: Gravitonium, an element which could have had a role in the Destruction of Earth. To Fitz, the fact that his designs had ultimately been used meant that they were trapped in a time loop paradox and that they would not succeed in saving the world, although Simmons disagreed.

The S.H.I.E.L.D. team tried to take off as the gravity storm approached, but the engines were too damaged. Simmons and Fitz suggested to use the gravity storm and the Gravitonium-based thrusters of the plane to fly anyway, to which the others agreed even if this plan was highly dangerous. Although the grounding anchors initially got stuck, Melinda May was finally able to take off the plane. Fitz signaled to May when she had to activate the thrusters and the plane stabilized into the outer space. Once in space, Fitz and Simmons requested the shard of the White Monolith from Deke Shaw so that they could split it in half and use the two fragments to return to their time.

New Monolith
"Yeah, well, still don't know how I'm supposed to build a time machine." "It's a portal, not a time machine."

- Flint and Leo Fitz

Fitz returned to the Lighthouse with the rest of his S.H.I.E.L.D. friends in the Zephyr One's Containment Module. Fitz and Jemma Simmons left with the shard of the White Monolith to find Flint ad Alphonso Mackenzie. While Simmons explained Flint how to master his powers so he could built another White Monolith, Fitz rigged the place with a trap should the Kree Watch find them. When three Kree guards arrived, Fitz activated his trap, which beheaded them instantly much to Simmons' discomfort.

Fitz, Simmons and Mackenzie reached Kasius' Suites, where Flint killed several other Kree guards, including Hek-Sel. Once the place was secure, Fitz apologized to Mackenzie for having killed the Kree guards under his eyes. When Mackenzie remarked that asking Flint to kill other guards did not help, Fitz noticed that his was his fiancée's idea, revealing their engagement to Mackenzie. The team was joined by Phil Coulson, Melinda May and an unconscious Daisy Johnson. In the end, Flint successfully built a new White Monolith. Deke Shaw called them and informed them that Enoch had decided to sacrifice himself to have the S.H.I.E.L.D. agents return to their time and that they needed to activate the machine. Fitz asked Enoch to hold on a little longer as Mackenzie, Simmons and Yo-Yo Rodriguez were still missing. Eventually, they returned just in time and the White Monolith was activated, sending Fitz and the others back into the present.

Piper and the Kree Orb
"This was installed by hand. A little sloppily, if you ask me." "I told you, I don't do science."

- Leo Fitz and Piper

Back in their time, Fitz and the other S.H.I.E.L.D. agents found themselves still in the Lighthouse, an abandoned S.H.I.E.L.D. bunker. Fitz and Melinda May searched the place for means of communication and discovered three Monoliths stored in secure boxes. They also encountered Noah, another Chronicom, who explained that the Monoliths' origin was unknown.

Noah explained to Fitz and the others that he was monitoring all of Earth activities. Upon noticing footage with beams of light seemingly coming from the sky, which was something Samuel Voss warned them about, the S.H.I.E.L.D. team decided to investigate the St. Louis Aerospace Facility. Using secret tunnels, they arrive in the city of River's End where they borrow a van. After a safe travel, albeit crowded and despite a police encounter, Fitz takes his friends to where he left the Zephyr One.

En route to the St. Louis Aerospace Facility, Fitz and Jemma Simmons reviewed the footage of the light beams and Fitz realized that if they corrected the image, the light did not come from the sky, but instead from the facility, emitting spreads identical to the Kree Orb used by Hive. Fearing that it could be used to make Kree come, Fitz and the team infiltrated the facility, where they were reunited with Piper. Piper explained that she had come to investigate and stop the Kree Orb as well. Fitz and Simmons studied the Kree artifact, but it activated once again. Fitz further examined the orb and found a man-made timer which had been implanted after the orb was reclaimed. At this moment, Piper drew her gun and pointed it at the S.H.I.E.L.D. agents, revealing she had actually struck a deal with General Hale to make the S.H.I.E.L.D. agents come as an armed squad invaded the facility.

Although Piper claimed that the squad were not there to hurt them, their leader, a masked feminine figure, ordered to kill them all. As the fight revealed that their opponents were revealed to be androids, Phil Coulson convinced Piper to help them, enabling Fitz and Simmons to take the Kree Orb. The S.H.I.E.L.D. agents managed to retreat to the Zephyr One, but Yo-Yo Rodriguez was heavily wounded, her arms being cut off by Ruby. Fitz and the rest of the team returned to the Lighthouse, where they discovered the presence of Deke Shaw. Fitz, Noah and Daisy Johnson took the Kree Orb to the Lighthouse secure storage room, where the Monoliths were kept as well. They kept studying the artifact, but Noah noticed that it was heating up. Figuring out that the Kree Orb was rigged to explode, Noah told Fitz and Johnson to leave right before the explosion, which only slightly wounded Fitz.

Discovering the Fear Dimension
"It seems that this dimension can take our deepest fears and it can manifest them physically."

- Leo Fitz

Fitz sent D.W.A.R.F.s to the floor where the Kree Orb had exploded to assess the damage caused by the blast, notably on the Monoliths. Although his drones were destroyed, Fitz managed to review the video feed on and one of them he saw an image of Lash, which was supposed to be dead. He also discovered an entire forest which had manifested on Level 27 of the Lighthouse. Further reviewing the feed, Fitz explained to his S.H.I.E.L.D. colleagues that the explosion of the Monoliths had caused a tear in spacetime which could have a role in the Destruction of Earth.

Fitz elaborated on his discovery, stating that the rift exposed their world to what he called a Fear Dimension, which generated illusions representing the S.H.I.E.L.D.'s agents greatest fears: Lash was manifested out of Melinda May's mind, the forest out of Deke Shaw's who found this vision terrifying and a Kree Warrior out of Daisy Johnson's. Fitz, who feared that the phenomenon could spread outside the Lighthouse, came up with a plan to contain it: using the Gravitonium contained in Shaw's Gravity Puck to craft a Gravity Containment Device. However, this device had to be placed right in the rift, putting the life of the one holding it in great danger.

This led to an argument between the S.H.I.E.L.D. agents. Indeed, Phil Coulson volunteered for the mission, which the others strongly disagreed. Fitz suggested sending out Piper, as she had betrayed them and was willing to do anything to make amends for it, but his idea was rejected. As Johnson and Coulson kept arguing in front of Fitz and May, Coulson suddenly had a respiratory distress which made him collapse on the ground. Fitz and the others then ran to find Jemma Simmons for help.

Fitz waited with the others S.H.I.E.L.D. agents for Simmons' diagnosis. Simmons explained that the old deadly would Coulson had suffered during the Battle of New York had festered and that the flesh went necrotic. Coulson explained that this was due to his possession by the Spirit of Vengeance when he defeated Aida, which left only one fate possible: Coulson was dying. Johnson angrily left, followed by Coulson, leaving Fitz and the others saddened by the reveal and the fact that there was nothing they could do about it.

Nonetheless, Coulson insisted on performing the mission. Fitz provided Coulson with a hazmat suit, a gas mask, a gun and the Gravity Containment Device and explained Coulson what he had to do, warning him one more time about the dangers of the Fear Dimension. Before Coulson departed, Coulson had Fitz promising that no matter what happened, he and Simmons would get married. At first, Fitz dismissed the idea, claiming that this was only a symbol and would not change anything, but upon seeing Coulson insisting as it would give hope to the others, Fitz nodded.

Fitz joined the others in the Lighthouse's control room. As Coulson seemed to be in trouble, Johnson was in favor of going and helping him, but Fitz advised her against it, claiming that they could not afford to lose two people instead of one. As they kept following Coulson's progression, they received an alarm indicating that an aircraft was incoming, and it turned out to be Shaw bringing S.H.I.E.L.D. reinforcements, including Deathlok, who went down and successfully helped Coulson to carry on the mission.

Long Expected Marriage
"I've been thinking about what to say, uh, just words don't really seem enough. I think that you are perfect and um, I don't deserve you, Jemma. I don't. I don't deserve you. And I'm well aware that I'm the luckiest man on any planet."

- Leo Fitz vows to Jemma Simmons

With the Fear Dimension momentarily contained and the S.H.I.E.L.D. agents being relatively safe in the Lighthouse, Fitz decided to keep his promise of marrying Jemma Simmons. He took the elevator down with Phil Coulson and Deke Shaw to the artificially generated forest. While in the elevator, Fitz kept discussing about the arrival of Deathlok and the other S.H.I.E.L.D. agents until Coulson asked him whether he was playing for time, as the elevator had arrived to their destination for a minute. Coulson then told Fitz that his wedding would be a great moment. Fitz got out of the elevator and joined his bride, who he said looked stunning in her wedding dress. Coulson then proceeded on celebrating the wedding, assuming that it was a long expected moment. Fitz and Simmons exchanged their vows and Fitz told Simmons that she was perfect and that he was well aware of his luck of having found such an ideal person who he thought he did not even deserve. Fitz then put a ring on Simmons' hand, officially marrying her. The two then tenderly kissed while their friends happily cheered around them.

Quest for Gravitonium
"You need to look up in the sky." "Our ships float and sink they don't fly. I'm sorry, Deke, but those are spaceships." "But what if the ship can fly? It was carrying Gravitonium during a storm. If it got hit by lightning..." "'Could have charged the Gravitonium."

- Deke Shaw and Leo Fitz

Fitz informed Phil Coulson that the Gravity Containment Device they had used on the Fear Dimension rift was not resistant enough, meaning that they needed more Gravitonium to craft an upgraded version of the device. Fitz joined a briefing held by Daisy Johnson who had investigated Cybertek, as they had previously possessed Gravitonium. During the briefing, Fitz noticed the presence of Deke Shaw, which annoyed him.

While the rest of the team left the Lighthouse in search for Dr. Joseph Getty, Fitz remained with Shaw, much to his annoyance as he had a hard time getting along with him. As Fitz struggled to find new leads for Gravitonium and Shaw unsuccessfully tried to distract him, Fitz received an alarm indicating that the Fear Dimension had become more active, meaning that illusions could be manifested. Fitz warned the people in the Lighthouse before going back to work. The team called Fitz to report the results of their interview with Getty, who mentioned the Principia, a ship which had sunk with a cargo of Gravitonium, but Fitz could not locate the ship. Once the call was ended, Jemma Simmons advised Fitz to get some rest, but he insisted on keeping working. As Shaw asked them naive questions about the sea, Fitz told him to leave, which led to an argument. Once Shaw left, Fitz remained with Simmons who asked him to act nicer towards Shaw. They then commented the fact that they were recently wed, joking about how they found it hard to believe and how they could change their first names. Shaw eventually returned to the control room, telling Fitz that he should look for the Principia in the sky and not in the abyss. As Fitz how Shaw was mistaken, he progressively realized that he might be right after all. Along with Shaw and Simmons, Fitz designed an algorithm to locate the ship which had been sent in the air when the Gravitonium was loaded with a lightning strike. Thanks to their work, S.H.I.E.L.D. was able to find the Principia.

Fitz monitored S.H.I.E.L.D.'s infiltration into the Principia, explaining to the team how the ship could fly in the air. At first, the search for Gravitonium appeared unsuccessful, but the team eventually found a small quantity which would be enough for Fitz. Fitz witnessed the team's fight against Sleeper Mechs and later welcomed them as they returned to the Lighthouse. Coulson handed over the Gravitonium to Fitz, who took it and instructed Shaw to come with him, trying to get along with the man who, unbeknownst to him, was his own grandson.

Psychic Split
"You had a psychic split. But that dark persona, that's not you." "It is me. It's not an apparition. It's not some evil doppelganger. It was me."

- Jemma Simmons and Leo Fitz

Fitz and Jemma Simmons began working on a new Gravity Containment Device to help seal the rift from the Fear Dimension. During a talk with Simmons, Fitz expressed his annoyance at the Fear Dimension, and wished for it to have been a 'wish dimension' instead. Around this time, Fitz and Alphonso Mackenzie began creating cybernetic arms for Yo-Yo Rodriguez. While talking with Simmons, an astronaut attacked her but Simmons eventually shot the astronaut until it turned to dust.

Fitz, Simmons, Daisy Johnson and Deke Shaw gathered in the control room of the Lighthouse where they brainstormed ideas to close the rift. The group decided to take a look at the old notes of Franklin Hall to better understand the properties of Gravitonium, where Fitz and Simmons went to take a look in the database. Shaw later went to see Fitz to try and bond with him, but got knocked out instead. Fitz stood and took off his helmet and jumpsuit, revealing himself to be The Doctor from the Framework. Later, while in the control room with Johnson, Fitz expressed his annoyance in not being able to find anything in Dr. Hall's notes, which resulted in a small, yet violent, outburst from him. Johnson tried to get him to calm down, but left when two cameras had gone down ten levels below control. After Johnson left, Fitz began to talk to himself until The Doctor appeared to Fitz, who believed the Doctor to be an illusion from the Fear Dimension. The Doctor claimed to be here to do what Fitz could not before Fitz heard a gunshot and Simmons calling for help. Fitz ran into the medical station where Simmons, Mackenzie and Rodriguez who had been attacked by a Sleeper Mech. Here, Fitz revealed that The Doctor was in the base. Fitz ran in search of Johnson and found her strapped to an operation table after she had been captured by another Sleeper Mech sent by The Doctor, who intended on removing her Inhuman Control Device, calling it the only way to compress the Gravitonium and thus seal the Fear Dimension. Fitz entered the room and as he and The Doctor argued over the latter's actions, Johnson asked who Fitz was talking to, just before Simmons burst into the room. Johnson, Simmons and Fitz himself discovered that The Doctor was not an illusion from the Fear Dimension: the dark personality resurfaced from times to times and took control of Fitz, making him capture and hurt Johnson. Despite Simmons' protests, Fitz stated that he had to continue what The Doctor had started. The Sleeper Mech then came into the room, holding Shaw and Simmons at gunpoint. Fitz then leaned on Johnson and painfully removed her inhibitor, despite Simmons urging him to reconsider due to the risks for both the Earth and Johnson herself. As Fitz extracted the inhibitor, Johnson told Fitz that she would never forgive him, to which Fitz replied that she would not be the only one. Once the device removed, Fitz instructed Johnson to use her powers to compress the gravitonium into the Gravity Containment Device so they could finally, once and for all, seal the rift. Fitz then allowed himself to be taken into custody.

Later, Fitz was visited by Simmons in his cell. The two began to talk, Simmons pointing out that Fitz had suffered a psychic split due to his prior brain injury, and that The Doctor was not actually him, to which Fitz replied that he was. Fitz then expressed that he believed he had done the right thing, and Simmons agreeing with him, much to his surprise. Simmons then left Fitz after talk about the uncertain future of their marriage.

Locked Up and Released
"I can't do anything while I'm locked away in this dungeon. Like a hideous, freckled stepchild."

- Leo Fitz

Fitz was visited in his cell by Melinda May, who was trying to locate Phil Coulson after he was captured by General Hale. Fitz was given all the intel gathered by May and Daisy Johnson about Hale and May asked him about any potential insight, even coming from his darker self. Fitz studied the documents and correctly inferred that Hale might have been looking for a HYDRA weapon she intended to use with Gravitonium. Knowing that S.H.I.E.L.D. needed all the help they could to find Coulson, Fitz suggested to be temporarily released so he could perform some research on the matter. However, Johnson, who had been eavesdropping all along, burst into the cell and categorically refused to let Fitz out. Fitz and Johnson began to argue about the former's actions, which he did not regret, causing Johnson to use her powers to throw Fitz against the wall. As Johnson called him a HYDRA agent and claimed that S.H.I.E.L.D. agents did not turn on each other, Fitz blatantly noticed that Johnson had effectively turned on S.H.I.E.L.D. on several occasions, which caused Johnson to angrily leave. Later, Fitz was visited by Jemma Simmons, who wanted to talk about their relationship. Fitz feared that Simmons would be driven away from him but Simmons reassured him, revealing the truth about Deke Shaw's lineage by presenting two versions of the same tool: one belonging to Fitz and the other belonging to Shaw who had obtained it through his grandfather. As Fitz, astonished, processed the reveal, Simmons explained to him that Shaw's existence proved that they would survive anything and that they were invincible.

Fitz was soon visited by his grandson, although he noticed that he did not see anything from himself in Shaw. Fitz and Shaw discussed what had happened under The Doctor's influence, and Fitz was surprised to hear that Shaw has grown some respect for him after what he did, claiming that Fitz had done exactly what Shaw had based his whole life upon: playing on the long game, which was the resemblance between Fitz and his grandson. Shaw then left Fitz after remarking that Johnson had become somehow rigid following Coulson's disappearance, something Fitz agreed to as he was still locked up in his cell.

Nevertheless, Fitz soon got an opportunity to get out of his cell. Indeed, Simmons took Yo-Yo Rodriguez to him. Much like Simmons, Rodriguez believed she could survive anything as she had seen herself in the future. Therefore, Simmons suggested that they, the "Invicible Three", left the Lighthouse to investigate the HYDRA weapon mentioned by Fitz. Although Rodriguez agreed, she warned them that Alphonso Mackenzie, who was in charge since both Coulson and Johnson were away, would never agree to let either Fitz or Rodriguez leave the base. Simmons and Rodriguez then left Fitz to work on their escape plan.

Simmons and Rodriguez came back to Fitz's cell, accompanied by Mackenzie. There, Fitz learned of Simmons' reckless plan, which consisted in filling three beakers with water and one with a toxic chemical and drinking the content of three of them without knowing what she would drink, in order to prove to Mackenzie that she was indeed invincible. Fitz rejected the plan, fearing to lose his wife, and watched in complete anxiety as Simmons drank the first two beakers, remaining unharmed. However, when she drank the third, Simmons collapsed on the ground, seemingly poisoned. Distraught, Fitz demanded to be released so he could fetch some drugs to try and save Simmons. Mackenzie agreed and unlocked the door and Fitz ran away to get the medicines. However, it soon turned out that Simmons had tricked Mackenzie so he would be locked in the cell and that she was actually safe. Upon discovering this, Fitz noticed that he would have appreciated to be warned of the trick but still expressed relief and hugged Simmons, congratulating her for her performance. However, Simmons revealed that the last beaker she had not drunk was indeed toxic and that she could have picked it, but had not thanks to her supposed invincibility.

Now free to go, Fitz, Simmons and Rodriguez left the Lighthouse with an auto-piloted Quinjet to investigate the possible locations of the HYDRA weapon sought by Hale.

Agitated Honeymoon
"I'm sorry you never got that honeymoon you dreamed of." "Nonsense. I'm protecting England from evil robots with the man I love."

- Leo Fitz and Jemma Simmons

To be added

Repairing the Chamber
"Let her go. You want this machine fixed, I need her help. Please. I'm engineering. She's biotech. We're a team."

- Leo Fitz to Ruby

To be added

Arguments and Dilemmas
"Ruby was dangerous and it got complicated, and that is just the way it was. So I'm sorry if that doesn't fit whatever narrative that you've built for yourself." "You need to look inside yourself and figure out what kind of man you want to be. 'Cause lately, what you've been, it needs fixing."

- Leo Fitz and Alphonso Mackenzie

To be added

Another Thing to Fix
"What about Glenn Talbot? You find a way to stop him? He's worse, too." "Yeah, we think so. Unfortunately, it's not a cure. It's more... It's more terminal."

- Alphonso Mackenzie and Leo Fitz

To be added

Personality
"It's like magic. But, it's– it's science."

- Leo Fitz

Like his best friend Jemma Simmons, Leo Fitz is known to be an attractive nerd on his profile for S.H.I.E.L.D., though he is somewhat socially awkward. Fitz also has a strange affinity for monkeys. He also has a great sense of humor, teasing Ward behind his back (in a mockery Southern accent), and planning to prank Skye. He is also a good actor, and easily impersonates an American tourist.

In spite of his lack of combat skills, Fitz impressed the more experienced Ward with his remarkable bravery and quick thinking during their mission together in South Ossetia. Fitz believes deeply in the friendships he creates: being upset when Skye appears to have been secretly working with Miles Lydon, actually crying when John Garrett revealed himself as HYDRA , as well as having a rare angry fit and emotional breakdown when Ward was revealed to be a murderer and a HYDRA mole. In return, Fitz is very loyal to his friends, is miserable when he was unable to save Skye from Quinn, and trusts Simmons with his life. Another instance of his loyalty was his refusal to serve Gonzales, deciding to leave rather than betray Coulson.

"Yes, they betrayed you. And after all you've been through, no one would blame you if you put up your own firewall. But you didn't. Instead you became the most open, loyal, caring person I've ever met."

- Jemma Simmons to Leo Fitz

While Fitz is devastated at Ward's betrayal, he is the only one on the team that still insists that Ward is redeemable, as Fitz believes that people are never "born evil." He is the only one who still tries to reason with Ward and implores him to let Garrett die and abandon HYDRA. Despite that, Fitz later on became very bitter against Ward after he dropped him and Simmons into the ocean to die and for betraying the team, even going on to torture him by suffocating him inside a cell as he did him, and later, attack him. However, Fitz is also very forgiving and understanding of others' problems, shown when he quickly forgives Skye for being so secretive about Miles Lydon, claiming that everyone "makes mistakes." He also instantly forgives Coulson for knocking him out with a punch, understanding the situation. As Simmons grows closer to Triplett, Fitz remains suspicious of him, though he does learn to trust him later on.

Fitz also tends to go through with his promises and threats: he promised Garrett that he would suffer for what he had done, and he (Fitz) plans to be a "very big part of that." By electrocuting and nearly assassinating Garrett shortly thereafter, Fitz manages to keep his word.

The brain damage Fitz suffered has caused him to become withdrawn after Simmons opted to be a part of an undercover mission. Fitz had hallucinations of Simmons and talked to her, claiming that those conversations calmed him. Billy Koenig had replaced him in many aspects, raising Fitz's jealousy. No one other than Skye and May interacted with him until Alphonso Mackenzie approached him, creating a new friendship between the two.

Since nearly losing Simmons to the Kree Monolith, Fitz has exhibited a tougher and more determined personality. His actions often put himself directly in harm's way, in order to protect those he loves. In order to find a way to get Simmons back, Fitz traveled to Morocco and negotiated with terrorists, risking his own life for a piece of parchment with the secret of the Monolith written on it. Once he returned to the Playground, he found out that the only word on the parchment is "Death". In his desperation, Fitz blasted the Monolith's container open with a shotgun and started beating on the rock furiously demanding that it swallow him. "I think that I'm a bad person."

- Leo Fitz after escaping the Framework

Whilst inside the Framework Fitz's personality was radically different to the point where he was the polar opposite from who he was in the real world. Ruthless, cruel, cold and sadistic and claiming to enjoy torturing people who HYDRA would capture. "The Doctor", as he was nicknamed, was willing to use his intelligence and scientific ability to further promote HYDRA's ideals, developing an agonizing experiment to find out an Inhuman's powers without triggering Terrigenesis. According to Fitz, victims of this experiment never survived, yet The Doctor had no qualms about carrying it out. This radical change was achieved when Aida removed Fitz's greatest regret, which was never having made amends with his father. In the Framework, Fitz's personality was deeply influenced by the education provided by his cold and ruthless father, who in turn was proud of his son's achievements within HYDRA. However Fitz still had doubts about doing the things he was doing like the killing of Agnes Kitsworth, even if his father dismissed these doubts as ""womanly sentiment". After escaping the Framework, Fitz was horrified by his behavior inside the alternate reality since it had led to the deaths of Kitsworth and Jeffrey Mace, and was afraid that his profound nature could be evil. Fitz was so wracked with guilt that he was unable to look at Simmons once he was out of the Framework without breaking down into tears. He also offered to sacrifice himself for the team by taking full responsibility for what had happened since the creation of Aida and the Framework. Moreover, being responsible for Mace's and Kitsworth's deaths was such a trauma to Fitz that he was unwilling to kill Aida and thus causing him to have another death on his mind, even if Aida had become a crazed, lethal enemy to S.H.I.E.L.D. Instead, Fitz tried to stop her by attempting to reason her and to have her express her pain by means other than violence, but his attempts failed as Aida was keen on making him suffer. "I know you're not a cold-blooded killer. Every light needs a shadow. You just have to learn how to control it, use it when you need it."

- Lance Hunter to Leo Fitz

Despite his expressed guilt and shame toward his actions in the Framework, minor traits of his alternate dark personality stayed with him, with an example being when Fitz forcefully threatened Enoch by holding him at direct gunpoint. Fitz initially rejected these remnants, stating that he could not accept it and was trying to bury it within him. However, after his friend Lance Hunter told him that all he had to do was do his best to control it, Fitz learned to use these traits to his advantage, thus allowing him to pose as a much more formidable and cruel individual than he actually is to blend in when dealing with dangerous individuals whenever the situation required it. As a result, Fitz sometimes displayed harsh pragmatism such as, for example, when he designed a trap which beheaded three Kree guards, so that others would be too frightened to chase the S.H.I.E.L.D. agents, which initially shocked Simmons. However, Fitz later apologized to Alphonso Mackenzie for having exposed the young Flint to such a vision. "I don't deserve forgiveness, Jemma." "Just like you don't deserve me?" "Mack's injured. Daisy's traumatized. Do you know what the worst part about all of this is? I still believe that it was the right thing to do."

- Leo Fitz and Jemma Simmons

Eventually, due to the combined trauma of his brain damage, his experiences in the Framework, a lack of sleep, and general stress, Fitz developed a major case of, becoming split between himself and his Framework personality. Fitz not only heard The Doctor, but also hallucinated his presence, which led Fitz to hurt Daisy Johnson as his subconscious knew the only way to achieve Fitz's goals was using her powers by painfully removing her Inhuman Control Device. Once it was done and Fitz returned to his normal self, he isolated himself from his friends once again, claiming that he did not deserve their forgiveness and struggling between his regrets of having hurt them and the feeling that he had nonetheless done the right thing.

Abilities
"I'm trapped in here! That's not possible! What did you do?!" "Science, biatch."

- Gordon and Leo Fitz


 * Genius Level Intellect: Fitz has become a very well known agent in the S.H.I.E.L.D. tech community for his technological expertise. Grant Ward's attempt to kill him damaged his temporal lobe, and he temporarily displayed as a result, a difficulty remembering or explaining words. However, this condition did not affect his intelligence, and Fitz continued being a genius. Over time, Fitz recovered from his brain troubles until he was released from the Framework and his intelligence was used by The Doctor, Fitz's evil self, to devise clever but harsh plans Fitz's true self was unwilling to come by.
 * Master Engineer: Fitz has designed and created many of the equipment commonly used by S.H.I.E.L.D. agents, including the Night-Night Guns and I.C.E.R.s, the Mouse Hole, the Magic Window. He has also created many of the tools used for analysis and scientific work, especially the D.W.A.R.F.s, the Golden Retrievers, the Full-Spectrum Goggles or the Magic Window. The sensitive nature of many mission has made him to develop devices against the clock that needed to be adapted to the parameters of each mission. As such, John Garrett was willing to recruit Fitz into HYDRA to benefit from his engineering abilities. Fitz's expertise also extends to artifacts of Asgardian origin, as his previous experience with the Berserker Staff allowed him to fully repair Lorelei's Asgardian Collar, greatly impressing Sif who considered him "quite clever".
 * Multilingualism: Fitz is able to speak some Arabic and to read Hebrew. He spoke Arabic when he confronted gangsters in Morocco to get to Yusef Hadad. When Fitz opened the scroll casing he had taken from him, he was instantly able to identify the symbol on the scroll as the Hebrew word for "death". However, he did not know that the word also had the meaning "death by punishment".
 * Marksman: Fitz was taught how to handle a handgun, and he resorted to use them to repeatedly shot Hive while possessing Will Daniels' body on Maveth, or to kill Giyera using a Cloaked Gun. After the Framework, this and his reflexes are greatly increased, as shown when he and Hunter take back the Zephyr and when Fitz, Simmons and Daisy escape Kasius and the bidders.
 * Expert Combatant: When Fitz first joined Coulson's Team, he was not a capable fighter. However, through his years of training with the team after joining, he became an adept combatant, being able to fight against a Primitive with great skill.
 * Spy: Though not at the level of agents like Melinda May or Natasha Romanoff, Fitz was able to convincingly play off that he was 'Boshtok the Marauder', a man who had a reputation for killing many, to Kasius and the bidders from around the galaxy. During this, he used his experiences from the Framework to his advantage to convince the group. In addition, Fitz is able to speak with a perfect American accent and thus can pose as an American rather than a Scottish man.

Weapons

 * I.C.E.R. Pistol: The I.C.E.R.s are S.H.I.E.L.D. Agents weapon of choice, coming out of the Night-Night gun designs. Fitz has repeatedly used this weapon throughout the series, most recently during the fight in the warehouse where Fitz and Lance Hunter found the Zephyr, and when Fitz, Simmons and Daisy escaped Kasius.
 * : The SIG Sauer P226 pistol is the standard sidearm carried by S.H.I.E.L.D. Tactical Agents. Fitz grabbed one of these weapons from one of the HYDRA operatives infiltrated into S.H.I.E.L.D. and used it to kill another before he could kill Melinda May during the Battle at the Hub.
 * : The Smith & Wesson M&P pistol is the standard sidearm carried by S.H.I.E.L.D. agents. Fitz was issued one when he was on the run from the S.H.I.E.L.D. faction led by Robert Gonzales, together with Phil Coulson and Lance Hunter.
 * : Fitz grabbed the compact version of the Smith & Wesson M&P standard pistol inside Castillo San Cristóbal in Puerto Rico to threaten Alphonso Mackenzie, who had been possessed by the Kree City and attacked his teammates to protect the city.
 * : Fitz obtained this handgun from a backpack carried by one of the HYDRA operatives that took him to Maveth. He used it when he discovered that Will Daniels had died, and Hive had possessed his corpse. Despite Fitz shot him many times, the Inhuman managed to survive all the shots.
 * : Fitz attempted to use one of these submachine guns against Giyera when he managed to escape containment inside Zephyr One and began to took over the plane. However, before he could shoot at him, Giyera easily took the weapon out of Fitz's hands.
 * : Fitz took a Mossberg 500 Cruiser from the arsenal in the Playground to break into the sealed room where the Monolith was being kept, in a desperate attempt to understand what happened to Jemma Simmons when she was swallowed up by the artifact.
 * : Fitz shot a flare with this gun towards the portal to Maveth when it was activated inside the HYDRA Castle. Jemma Simmons saw the flare, and went towards the flare, managing to return to Earth but leaving Will Daniels behind.
 * : Fitz obtained this handgun from the backpack carried by one of the HYDRA operatives that took him to Maveth. He used it against Will Daniels' corpse, who had possessed by Hive, as shots with a Glock 17 pistol proved to be harmless. The flare made Daniels' corpse to burn, leading Fitz he had killed the creature.
 * Night-Night Pistol: Leo Fitz designed the pistol version of the Night-Night Gun for his teammates, but he also began to carry two of them during his field missions with the rest of his team. Fitz used it to repeatedly shot at the already unconscious member of the Cybertek security team that attacked Jemma Simmons in a train in Italy, leaving the gun with an unconscious Simmons to protect herself once she woke up.
 * Overkill Device: Fitz modified the Overkill Device he was sent to deactivate in South Ossetia, and used it as a handheld weapon to disarm the separatists that were about to attack him and Grant Ward.
 * Destroyer Armor Prototype Gun: Under Phil Coulson's explicit orders, Fitz procured and fired the Prototype Gun against Vin-Tak, a Kree who was fighting Bobbi Morse when he tried to kidnap Skye due to her status as an Inhuman.
 * Cloaked Gun: Fitz used this gun to kill Giyera.

Other Equipment

 * D.W.A.R.F.s: Fitz often used the D.W.A.R.F.s in order to analyze and retrieve forensic data during his field missions, such as in the Centipede laboratory in Los Angeles, the temple where an 0-8-4 was located in Peru, the StatiCorp facility in Utah and even the Kree City under Puerto Rico. He also used them to try to stop criminals Vanchat and Marcus Daniels.
 * Localized EMP Device: Fitz retrieved a Localized EMP Device from the Hub and carried it during his dangerous mission to South Ossetia, using it to force a blackout and gain a local mob's trust by fixing it.
 * MAG Pouch: Fitz carried a MAG Pouch during his dangerous mission to South Ossetia, using it to adhere to the underside of a track and enter a separatist compound with Grant Ward.
 * Magic Window: Fitz carried a Magic Window during his dangerous mission to South Ossetia, using it to see through the walls of the separatist compound.
 * Spectrographic Analyzer: Fitz resorted to the use of an Spectographic Analyzer to determine the origin of each and every piece of debris found after the Battle of Greenwich.
 * Golden Retrievers: Fitz has used his Golden Retrievers in order to track individuals over a relatively great distance, such as tracking Tobias Ford in Utah or Deathlok in Florida.
 * Tracker: Fitz intended to use a Tracker on the package that Cybertek was delivering to Ian Quinn, but he ended up using it to inform the rest of his team about his and Skye's location in Ian Quinn's Villa.
 * Mouse Hole: A device created by Fitz that was not mass-produced, but kept by S.H.I.E.L.D.'s highest agents, such as Nick Fury and Maria Hill. He kept one for himself, and used it to cut a hole through the Bus and infiltrate the Hub.
 * Cigarette Laser: Fitz tried to demonstrate that the items of the Howling Commando Gear were more than they appeared, and started to pretend he was smoking the Cigarette Lasers. However, the only thing he managed to do was to set the drapes on fire.
 * Quarter Walkie-Talkie: Fitz and Antoine Triplett shared a pair of Quarter Walkie-Talkies as they investigated John Garrett's headquarters in Cuba, leaving it in the Bus and allowing the rest of his team know that the plane had returned to the United States of America.
 * EMP Joy Buzzer: Fitz used the device against John Garrett, damaging his cybernetic prosthesis and bringing him to the brink of death.
 * Forensics Scanner: A forensics device used in the investigation of the man that battled Lady Sif in Portugal.
 * Three Dimensional Scanner: Fitz used Three Dimensional Scanner to analyze the remains of a wall that Lash had disintegrated in order to escape from Lori and Shane Henson's apartment.
 * Backscatter Glasses: Fitz used the Backscatter Glasses during the mission to find Holden Radcliffe.

Fitz-Simmons Designs
"I'm engineering, she's bio-chem."

- Leo Fitz

Family

 * Grandmother
 * Alistair Fitz - Father
 * Alistair Fitz † - Father (Framework)
 * Mother
 * Mother † (Framework)
 * Jemma Simmons - Colleague, Best Friend and Wife
 * Daughter † (alternate timeline)
 * Owen Shaw † - Son-in-Law (alternate timeline)
 * Deke Shaw - Grandson (alternate timeline)

Allies

 * S.H.I.E.L.D. (First Incarnation) (Former Relationships)
 * Nick Fury † - Director and Savior
 * Maria Hill † - Deputy Director
 * Victoria Hand † - Superior Officer
 * Felix Blake - Colleague
 * Eric Koenig † - Colleague
 * Billy Koenig - Colleague
 * Jazuat - Colleague
 * Davis - Colleague
 * Garrett's Team - Colleagues
 * John Garrett † - Friend
 * Antoine Triplett † - Rival and Friend
 * S.H.I.E.L.D. Academy of Science and Technology
 * Anne Weaver - Former Teacher and Friend
 * Franklin Hall † - Former Teacher
 * Professor Vaughn - Former Teacher
 * Sally Webber - Fellow Cadet
 * Coulson's Team - Teammates
 * Phil Coulson - Team Leader and Friend
 * Jemma Simmons - Best Friend
 * Melinda May - Friend
 * Skye - Friend
 * S.H.I.E.L.D. (Second Incarnation)
 * Phil Coulson - Colleague, Former Director and Friend
 * Jeffrey Mace † - Director
 * Melinda May - Colleague
 * Daisy Johnson - Colleague, Best Friend and Temporary Enemy
 * Antoine Triplett † - Colleague and Friend
 * Alphonso Mackenzie - Colleague, Good Friend, and Temporary Enemy
 * Yo-Yo Rodriguez - Colleague
 * Isabelle Hartley † - Colleague
 * Idaho † - Colleague
 * Billy Koenig - Colleague
 * Sam Koenig - Colleague
 * Michael Peterson/Deathlok - Enemy (while under HYDRA Coercion) turned Colleague and Friend
 * Robert Gonzales † - Enemy turned Ally
 * Anne Weaver - Former Teacher and Colleague
 * Anderson - Colleague
 * Nathanson † - Colleague
 * Burrows † - Colleague
 * Navarro - Colleague
 * Flynn - Colleague
 * Crawford - Colleague
 * Morales - Colleague
 * Wahl † - Colleague
 * Secret Warriors - Colleagues
 * Lincoln Campbell †
 * Elena Rodriguez
 * May's Team - Colleagues
 * Piper
 * Prince †
 * Davis
 * Akela Amador - Enemy (while under HYDRA Coercion) turned Ally
 * Elliot Randolph
 * Sif †
 * Lance Hunter - Former Colleague and Friend
 * Bobbi Morse - Former Colleague and Friend
 * Andrew Garner/Lash † - Ally and Temporary Enemy
 * Joey Gutierrez - Former Colleague
 * Advanced Threat Containment Unit - Situational Allies
 * Rosalind Price †
 * Luther Banks †
 * Robbie Reyes/Ghost Rider - Savior
 * HYDRA (Framework) - Former Employers under Coercion
 * Sunil Bakshi †
 * Jemma Simmons (Life-Model Decoy) †
 * Enoch † - Friend
 * Polly Hinton
 * Robin Hinton
 * Flint
 * Noah † - Savior

Enemies

 * Milton
 * HYDRA
 * Grant Ward † - Former Teammate and Friend
 * Jasper Sitwell † - Former S.H.I.E.L.D. Superior
 * Daniel Whitehall †
 * Sunil Bakshi †
 * Centipede Project
 * John Garrett † - Former S.H.I.E.L.D. Superior and Attempted Victim
 * Ian Quinn †
 * Kaminsky
 * Raina †
 * Giyera † - Victim
 * Gideon Malick †
 * Hale †
 * Ruby Hale † - Attacker
 * Werner von Strucker †
 * Sleeper Mechs
 * Camilla Reyes - Ally turned Enemy
 * Cybertek
 * Carlo Mancini †
 * Agent 33 †
 * Afterlife Inhumans
 * Jiaying †
 * Gordon † - Victim
 * Lorelei - Enemy turned Enthraller
 * Vin-Tak
 * Calvin Zabo - Enemy and Situational Ally
 * Yusef Hadad
 * Watchdogs
 * Felix Blake - Former Colleague turned Enemy
 * Anton Ivanov †
 * Dallas Wyatt
 * Watchdog Oscar - Attempted Killer
 * Briggs
 * Chinatown Crew
 * Hive †
 * Primitives †
 * O'Brien - Colleague turned Enemy (brainwashed)
 * Frederick † - Attempted Killer
 * Eli Morrow †
 * Holden Radcliffe † - Friend and Colleague turned Enemy
 * Aida † - Ally and Lover in the Framework turned Enemy
 * Life-Model Decoys
 * Holden Radcliffe (Life-Model Decoy) † - Victim
 * Melinda May (Life-Model Decoy) †
 * Inhumans † (Framework)
 * Lincoln Campbell † - Test Subject and Victim
 * Gordon † - Test Subject
 * Vijay Nadeer † - Captive and Test Subject
 * Agnes Kitsworth † (Framework) - Victim
 * S.H.I.E.L.D. (Framework)
 * Grant Ward †
 * Antoine Triplett †
 * Burrows †
 * United States Armed Forces
 * Evans † - Temporary Ally
 * Lucas †
 * Kree Watch
 * Kasius †
 * Sinara †
 * Faulnak †
 * Maston-Dar † - Attempted Killer
 * Gaius Ponarian
 * Karaba
 * True Believers - Rescuers turned Enemies
 * Sam Voss
 * Hive (Illusion) †
 * Confederacy
 * Glenn Talbot † - Ally turned Enemy and Killer
 * Remorath

Trivia

 * Fitz is apparently a fan of the long-running, British Sci-fi television show,  as he has a model of the Doctor's beside his bed.
 * Fitz has a distaste of corpses contaminating his work space after Jemma Simmons left a liver from a dead cat she was working on next to his lunch.
 * Fitz is the first and only known person that Agent Melinda May has pranked after she became grim and seemingly unemotional.
 * Fitz greatly impressed Lady Sif herself, who admitted that he was "quite clever."
 * Fitz can do a perfect American accent, due to watching a lot of American TV in his childhood. He also does a mockery Southern accent while teasing Ward behind his back.
 * Fitz is the first member of Coulson's team that almost kills the "Clairvoyant", John Garrett. Thus, Fitz becomes, quite possibly, the one Garrett hates the most, since the latter immediately ordered Ward to kill him.
 * Fitz's favorite sandwich is: prosciutto, buffalo mozzarella, and a touch of pesto aïoli on what looks like a baguette.
 * Fitz doesn't have any ex-girlfriends, which means that prior to Simmons, he has never had a romantic relationship with a woman.
 * Fitz along with Simmons took History of S.H.I.E.L.D., Neurobiology and ChemLab at Sci-Tech.
 * Fitz as part of a prank, tells Skye she needs at least 2 semesters of Holographic Engineering to be able to touch the Holotable.
 * During his Lie Detector test, the one item Fitz would choose if he was stranded on a desert island would be Simmons.
 * Fitz's favorite thing in the world is Jemma Simmons.
 * Fitz is a football fan, and a supporter of.
 * After freezing himself for 74 years, Fitz is now, canonically, the oldest human character within the MCU, after the death of the Ancient One and presumed deaths of the members of the Hand. Before this event, The Winter Soldier was the oldest, but is three years younger (in terms of years alive in any timeline, as Fitz woke up in the future before travelling back to the past. His body has still been alive for over 100 years.)

Behind the Scenes

 * The relationship between Fitz and Jemma Simmons is based on the relationship between Jed Whedon and Maurissa Tancharoen.
 * Fitz's obsession with monkeys was inspired by Iain De Caestecker's real life love of monkeys.
 * Due to his popularity, Leo Fitz was introduced into the main Marvel Comics universe.
 * Fitz also appeared on the animated show Ultimate Spider-Man.
 * Justin Gant, Josh Fried and Tim Mikulecky were stunt doubles for Iain De Caestecker in the role of Leo Fitz.