Leo Fitz

"And I should be there with them, but I can't be because of you, because of what you did to me!... I'm damaged!"

- Leo Fitz to Grant Ward Leopold "Leo" Fitz is a Scottish-born S.H.I.E.L.D. agent and scientist. A genius, 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 best friend, Jemma Simmons. He, along with Simmons, was recruited to Coulson's Team by Melinda May 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, he became jealous of Simmons' friendship with Agent Antoine Triplett. 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, resulting in several arguments with Simmons and the rest of the team. Fitz was captured by HYDRA along with Simmons, and met Ward again.

When Ward was ordered to kill them, Fitz fruitlessly begged Ward to have mercy, and was dumped into the ocean in the Bus' Medical Pod with Simmons. They survived the fall, but were trapped on the ocean floor. Fitz devised a plan using the pod's oxygen bottles to get them out of the pod and to safety, but there was only enough oxygen for one, and while confessing romantic feelings for Simmons, he saved her. However, this resulted in him spending 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. 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.

Early Life
Leopold Fitz was born in Scotland, United Kingdom on Wednesday, August 19, 1987. A genius-level engineer, whose only other relative is his mother, 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.

Fitz and 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.

First Missions for 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 inflitrated the billionare'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 inhuman 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
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 Simmon's 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 Simmon's 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. When he did, he took it to Skye for Simmons to inject her with it, fully healing his teammate.

Secrets
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. 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
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 Mack 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
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 Mack told Fitz. Fitz and Mack 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 Mack and Fitz played video games, because, according to Mack, playing helped Fitz's brain. Mack 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 City Blueprints before HYDRA can.

Muscle Memory
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 rebuilting 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 City Blueprints 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 City Blueprints. 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 Mack 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
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. She 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
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 would call him that. Mack told Fitz that he would always be his friend and asked him not to leave. As they were talking, Mack revealed that Simmons was working on accessing the Toolbox using Coulson's DNA.

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 pulled the real Toolbox from the bag Simmons gave him, along with his favorite sandwich. 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. He accessed Phil Coulson's tablet from the box and contacted him and Lance Hunter. However, other patrons (Gonzales' agents in disguise) began to become impatient and banged on the door. Fitz asked Hunter for a way out, and Hunter began describing an escape method.

Seeing Ward Again
"Desperate times, desperate measures. Count me in."

- Leo Fitz

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. 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 Ward, Fitz was not happy. Hunter pointed out that their jobs sometimes required them to work with people whom they despised. When Coulson and Deathlok brought in Ward and Agent 33, Fitz sat on an opposing side of the Quinjet, fingering his gun. Ward asked how Fitz was doing, and Fitz leaped from his seat at him only to be held back by Coulson and Hunter. Fitz calmed down, but would not answer Ward's question. When a supposedly brainwashed Sunil Bakshi set up a meeting with List, Fitz watched through Deathlok's eyes with the others. When Bakshi offered up Deathlok as incentive, the Quinjet erupted, 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. Later, after Coulson turned himself into Gonzales and the two worked out an arrangement to stop HYDRA, Coulson had Fitz, Hunter, Ward, and Agent 33 board the plane. 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
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 an 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 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 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 Coulsom 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 didn't 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 talking about how 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 there 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 realised 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 gave in 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. 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.

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.

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 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 her as an imaginary friend and frequently 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.

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 displays as a result, a difficulty remembering or explaining words. However, this condition has not affected his intelligence, and Fitz continues being a genius.
 * 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. His 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.

Weapons

 * : 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.
 * 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.

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 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.

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

- Leo Fitz

Family

 * Grandmother
 * Mother

Allies

 * S.H.I.E.L.D. (First Incarnation) (Former Relationships)
 * Nick Fury - Director
 * 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
 * Coulson's Team - Teammates
 * Phil Coulson - Team Leader and Friend
 * Jemma Simmons - Best Friend and Love Interest
 * Melinda May - Friend
 * Skye - Friend
 * Grant Ward - Friend
 * S.H.I.E.L.D. (Second Incarnation)
 * Phil Coulson - Director and Friend
 * Melinda May - Colleague
 * Daisy Johnson - Colleague and Friend
 * Jemma Simmons - Colleague, Best Friend, and Love Interest
 * Antoine Triplett † - Colleague and Friend
 * Lance Hunter - Colleague and Friend
 * Alphonso Mackenzie - Colleague and Good Friend
 * Bobbi Morse - 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
 * Akela Amador - Enemy (while under HYDRA Coercion) turned Ally
 * Elliot Randolph
 * Sif

Enemies

 * Raina †
 * 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
 * Ian Quinn
 * Kaminsky
 * 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

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 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 he never had a romantic relationship with a woman.
 * Fitz along with Simmons took History of S.H.I.E.LD, 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.

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.