Season synopsis
Contains spoilers for this season and earlier seasons.
After Coulson’s death, Mack leads a rebuilding S.H.I.E.L.D. while Daisy, Simmons, Piper and Davis search space for Fitz, last seen in cryosleep with Enoch. On Earth, portal-borne Shrike infect people. Another arrival, Sarge, looks like Coulson but has no clear memory of the team. His crew kidnaps May; the agents learn the Shrike spread between hosts and turn people into lethal crystal growths. Yo-Yo loses her partner Keller when a parasite infects and kills him.
Fitz and Simmons reunite after space journeys and capture by Chronicoms seeking time-travel knowledge. They return to Earth with Izel, an alien who wants the three Monoliths, or Di’Allas, because they can open a passage to her world. Sarge claims to oppose Izel, but his memories are unreliable. He and the agents clash over the Shrike tower and a bomb intended to destroy Izel; when that plan fails, Mack and Yo-Yo free the team from Izel’s ship, and Jaco sacrifices himself to detonate the bomb. Sarge survives May’s apparent killing and is revealed as a being tied to Izel, not Coulson returned.
Izel possesses people at the Lighthouse and uses Flint’s abilities to rebuild the Monoliths, opening the portal. Daisy and May try to reach the trace of Coulson inside Sarge, but Sarge stabs May and throws her through the gateway. She awakens on the other side, then returns to kill Izel with Sarge’s blade. Mack cuts Sarge in two. May’s wound becomes life-threatening back on Earth. Chronicom hunters raid the Lighthouse to claim Earth. Simmons arrives with an upgraded Zephyr and saves May, then Fitz’s jump drive carries the team to 1930s New York. Simmons reveals that she and Fitz built a Chronicom-enhanced LMD of Coulson to help defend S.H.I.E.L.D.