With time running short, the team will have to go to hell and back to stop the end of everything. Who will survive?
In the Lighthouse, Leo Fitz, Jemma Simmons and the other S.H.I.E.L.D. agents are shocked as they witnessed Melinda May being stabbed and sent through a portal by Sarge in the Temple of the Forgotten. They alert Daisy Johnson of this situation in the Zephyr One, and Johnson blames herself for having trusted Sarge. As they decide that May's apparent death cannot be in vain, they are contacted by Deke Shaw, who is stuck in the Quinjet they previously used. Alphonso Mackenzie thus guides Shaw through the aircraft's take-off so he can join them.
In addition to the threat of Izel, Fitz and Simmons soon have to deal with another enemy: an entire squad of Chronicom Hunters led by Malachi invade the Lighthouse and wreck havoc in S.H.I.E.L.D.'s ranks. Using the memories of Fitz and Simmons the Chronicoms previously collected, the Hunters are able to predict where the agents will hide and kill many of them, including Trevor Khan, much to Fitz's and Simmons' dismay, who figure out that they are a liability.
Entrusting the lives of the other agents to Diaz, Fitz and Simmons fear that Malachi, who has already seized the Toolbox, wants to use the data collected on the S.H.I.E.L.D. agents who were connected to the Framework. They rig the room where the equipment is stored with bombs and plan to sacrifice themselves to ensure the Chronicoms will fail, but they eventually get assistance from Enoch, who had taken the appearance of Isaiah. Enoch explains that he has a way of stopping Malachi from turning Earth into the new Chronicom world, but that it will change Fitz's and Simmons' lives forever.
Meanwhile, in the Temple of the Forgotten, Sarge and Izel, despite an argument about Izel's actions, wait for their kind to invade Earth from the Fear Dimension through the portal previously opened by Izel. In this dimension, The First, The Second and The Third, prepare to open a gateway with fragments of the Space, the Time and the Creation Di'Alla. However, they are stopped in this endeavor by May, who barely survived her stab wound but is able to slay them nonetheless.
Shaw manages to take the Quinjet off to reach the Zephyr One, where Quake and Yo-Yo Rodriguez attempt to repel the Shrike hosts who have invaded the aircraft. They manage to take them down, but one Shrike survives and rushes into Rodriguez's mouth, infecting her and thus putting her life at risk. Despite this, Mackenzie, Quake, Rodriguez and Shaw take the Quinjet near the Temple of the Forgotten.
Izel figures out that something went off in her plan and suspects that Sarge purposefully spared the life of May. She goes through the portal and is confronted by May, who can survive since the concept of life and death operate differently in the Fear Dimension. The two women engage in a violent swordfight, and although Izel is defeated, she manages to open the portal so her kind can gain access before escaping through the portal.
On the other side of the portal, Quake, Mackenzie and Rodriguez go to confront Sarge while Shaw is tasked with repelling the Shrike hosts. However, Sarge turns out to be unaffected by Quake's powers. Mackenzie fights against Sarge at length, but is unable to defeat him. Moreover, the Shrike inside Rodriguez gets on the verge of bursting out of her and killing her, with Quake being unable to give Rodriguez a merciful death with a Shrike Dagger.
Quake eventually resumes the fight against Sarge, but Izel gets out of the portal behind her and nearly stabs her to death. However, May manages to follow her through the portal and strikes her down with the very sword Sarge used to stab her. She then tosses the sword to Mackenzie, who catches it and uses it to slay Sarge. With Izel's death, all the Shrike are killed, thus saving Rodriguez, while the portal to the Fear Dimension is shut down.
May loses consciousness in Quake's arms, hoping that she will be able to be reunited with Phil Coulson. Nevertheless, before she dies, Simmons arrives with a team of agents, who sample a fragment of the Time Di'Alla. Simmons brings her friends back into Zephyr One, with May being put into a Cryo-Freeze Chamber. Simmons then activates the plane's Phase Harmonic Teleportation Device, which causes the Zephyr to teleport, and the Ionizer Missiles shot by the Chronicoms thus miss them and instead destroy the Temple of the Forgotten.
Zephyr One is teleported above the skies of New York City, and the team sees the Empire State Building still under construction. They realize that the Phase Harmonic Device not only took them through space, but through time as well, and that they have traveled back in time to 1931. Indeed, Simmons explains that they need time to figure out exactly what S.H.I.E.L.D. secrets the Chronicoms are after to take over the Earth. To that end, Simmons reveal their last asset, created with Enoch to act as an expert in S.H.I.E.L.D history: a new Life-Model Decoy of Coulson, which is activated by Quake despite Mackenzie's hesitation.
- Clark Gregg as Pachakutiq/Sarge / Phil Coulson
- Ming-Na Wen as Melinda May
- Chloe Bennet as Daisy Johnson/Quake
- Iain De Caestecker as Leo Fitz
- Elizabeth Henstridge as Jemma Simmons
- Henry Simmons as Alphonso Mackenzie
- Natalia Cordova-Buckley as Yo-Yo Rodriguez
- Jeff Ward as Deke Shaw
- Joel Stoffer as Enoch
- Karolina Wydra as Izel
- Christopher James Baker as Malachi
- Jan Uddin as Enoch (disguised as Isaiah)
- Shainu Bala as Agent Trevor Khan
- Christian Ochoa as Baal-Gad
- Geri-Nikole Love as Agent Diaz
- Eric Schloesser as The First
- Kevin Stea as The Second
- Gina Gonsalves as The Third
- Unknown Actor as Hazmat Suit #1 (uncredited)
- Unknown Actor as Hazmat Suit #2 (uncredited)
- Unknown Actor as Hazmat Suit #3 (uncredited)
- Unknown Actor as Hazmat Suit #4 (uncredited)
- Lake Ontario, New York
- Yucatán, Mexico
- New York City, New York
- Izel's Campaign
- War Against the Chronicoms
- Yo-Yo Rodriguez' Prosthetic Arms
- Quake Gauntlets
- Sonic Barrier Cuffs
- Inter-Planetary Conveyance Disc
- Chronicom Rifle
- Sarge's Sword
- Theta Brain-Wave Frequency Machine
- Izel's Daggers
- Shrike Daggers
- Cryo-Freeze Chamber
- Phase Harmonic Teleportation Device
- Ionizer Missiles
- Remorath Rumble (mentioned)
- Daniel Sousa's Prosthetic Leg
- Cerebral Fusion Machine (mentioned)
- The pose Melinda May takes before fighting Izel is similar to the one Mulan adopts during her battle against Shan Yu a the end of the 1998 animated film Mulan. May's actress, Ming-Na Wen, voiced Mulan in the film.
- Wen later confirmed that the pose was done as a reference to Mulan.