Out of answers and running out of time, the agents must face the ghosts of their past in order to move forward.
In the Zephyr One, Izel, now possessing Alphonso Mackenzie after leaving Yo-Yo Rodriguez unconscious, tricks the latter into revealing the name of Marcus Benson as the only one who knows where the Temple of the Forgotten, where Izel wants to rebuild the Di'Allas, is located. Once Benson is taken into the plane, Rodriguez secretly alerts him that Mackenzie is being possessed, causing Benson to delete the data he collected. This forces Izel to kill a S.H.I.E.L.D. agent and to reveal herself, ordering Benson to give her the location of the temple.
In order to force Benson, Izel uses the energy of the Di'Allas stored in the Gravity Containment Device. This creates an illusion of Benson's late husband, which is then destroyed by Izel, thus confronting Benson with the repeated death of the love of his life. Unable to stand it, Benson agrees to give up the location of the temple. Despite this setback, Mackenzie and Rodriguez are able to trick Izel into accidentally releasing Benson from the plane, so he can be found by the rest of S.H.I.E.L.D. and lead them to the temple.
In the Lighthouse, S.H.I.E.L.D. desperately looks for a way to fight against Izel, with Leo Fitz and Jemma Simmons struggling to comprehend how her powers work. Melinda May interrogates Sarge, but her point of view is biased by the fact that she believes Phil Coulson to be buried somewhere in Sarge's body. Getting angry, Sarge begins to reveal his full might, denting the table he is sitting at. Daisy Johnson then confronts May, criticizing her way of interrogating Sarge and claiming that they should instead try to unleash whatever force is inside Sarge as it is supposedly able to destroy Izel.
Therefore, Johnson goes, in turn, to interrogate Sarge, although she makes little progress. She then returns to Fitz and Simmons, who suggest that they could build weapons against Izel, but it is not enough for Johnson as she refuses to use a weapon on a potential host used by Izel. Simmons incites Johnson to resume her interrogation of Sarge, but by actually listening to whatever he has to say, instead of focusing her attention on how he looks like Coulson, who Johnson misses more than she wants to admit. In tears, Johnson goes to her room and retrieves a letter left to her by Coulson she never read.
Johnson finally opens the letter, which gives her the strength to fully accept the truth: Coulson is gone and will never come back, no matter how things seem to be with Sarge. Johnson then returns into the room Sarge is being detained in and asks him about the memories Sarge sees more clearly after being shot by Izel. Since the thing inside him began to reveal itself after Sarge seemingly died, Johnson snaps his neck with her powers, much to the shock of Fitz, Simmons and Deke Shaw watching. Just like the previous time, Sarge's body seems to quickly recover. Piper is also reluctant to give in to such an idea after what happened when Izel was unleashed in the Lighthouse.
Sarge eventually regains consciousness, with more of his might recovered. He abruptly decides to leave the room and attacks Johnson, incapacitating her and blasting his way out of the cell. Now fully ready to kill Sarge if he does not cooperate, Johnson reclaims his sword and goes after him in the corridors of the base as Sarge attempts to leave. She threatens to slay Sarge with the sword, but as Sarge dares her to do it, he calls her "Skye", a name only Coulson could have known while Sarge could not. Acknowledging that Sarge was willing to sacrifice himself just like Coulson would have, Johnson decides to trust him and hugs him.
Shaw reviews footage of the confrontation between Johnson and Sarge and figures out how Izel's powers work: she uses harmonic frequency resonance to control hosts at an atomic level. This enables Shaw, Fitz, and Simmons to begin working on the Sonic Barrier Cuffs which will help them counter Izel. May relays the information to Piper, who in turn tells May that they have found Benson. May then visits Johnson, who voices her confidence that Sarge will help them if they are willing to trust him as well.
In the Temple of the Forgotten, Izel ties up Rodriguez and Mackenzie to a pillar. She then unleashes the energy of the Di'Allas, planning to use it to build a portal to the Fear Dimension so her kind can invade Earth. To that end, she exposes the energy of the Di'Allas to Rodriguez and Mackenzie, and their unconscious fears cause the manifestation of an illusion of Flint, the young Inhuman they met in the 2091 Lighthouse, whose geokinesis powers could be used by Izel to rebuild the Monoliths.
Meanwhile, the Chronicom Hunters have reviewed the memories of Fitz and Simmons collected in the Cerebral Fusion Machine. However, Malachi voices his objections to Atarah's plan: to him, the Chronicoms should focus on finding another planet to turn into their new homeworld instead of trying to restore Chronyca-2. Atarah rejects the initiative, but she actually already lost the leadership of the Chronicom Hunters and ends up murdered by Malachi, who takes her place and sends his hunters to their new targets.
- Clark Gregg as Pachakutiq/Sarge
- 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 / Izel
- Natalia Cordova-Buckley as Yo-Yo Rodriguez / Izel
- Jeff Ward as Deke Shaw
- Karolina Wydra as Izel
- Barry Shabaka Henley as Doctor Marcus Benson
- Briana Venskus as Agent Piper
- Robb Derringer as Tom Benson (illusion)
- Coy Stewart as Flint (illusion)
- Christian Ochoa as Baal-Gad
- Sherri Saum as Atarah
- Christopher James Baker as Malachi
- Eric Schloesser as The First (uncredited)
- Kevin Stea as The Second (uncredited)
- Gina Gonsalves as The Third (uncredited)
- Chronyca-2 (mentioned)
- Izel's Campaign
- Search for Leo Fitz
- War Against the Chronicoms
- Battle of the Playground (mentioned)
- Yo-Yo Rodriguez' Prosthetic Arms
- Quake Gauntlets
- Gravity Containment Device
- Sarge's Sword
- Shrike Daggers
- Di'Allas (picture)
- Shrike (mentioned)
- Phil Coulson
- Robbie Reyes
- Spirit of Vengeance (indirectly)
- Damon Keller
- Lincoln Campbell
- Tom Benson
- Grant Ward
- Google Maps
- Ley lines