Stranded in New York City in 1931, L.M.D. Coulson and the S.H.I.E.L.D. team go undercover on the ground to stop the Chronicoms from changing the past and preventing S.H.I.E.L.D. from ever being formed.
Mack and Deke are tasked with protecting a young bootlegger being targeted by the Chronicoms, though he will later play a role in creating Hydra. Enoch must tangle with Agent May after she wakes up early, and not entirely herself.
The Zephyr jumps forward to New Mexico in the 1950s, where the Chronicoms have targeted a top-secret weapons project at Area 51. Simmons poses as Peggy Carter, only to come face-to-face with the S.H.I.E.L.D. agent's former partner.
In 1955 Coulson sets his mind to helping Agent Sousa make a vital delivery, knowing that history tells the story of Sousa's heroic death. Meanwhile Deke comes face-to-face with Hydra's most powerful, and May learns more about what has happened to her.
After arriving in 1970s New York the agents discover that Wilfred Malick is in league with the Chronicoms, plotting to use the launch of S.H.I.E.L.D.'s Project Insight to target future heroes.
When the Chronicoms improve their replacement technology Coulon and May track them to their ship, while Mack and Yo-Yo try to help his parents escape the facility. As Jemma struggles to repair the Zephyr, Daisy and Sousa are held captive by an ambitious and power-hungry Nathaniel Malick.
After he and Deke are stranded in 1982, a despondent Mack withdraws from human contact -- while Deke assembles a team of his own to prepare for the coming fight. Sibyl uses a vulnerable computer nerd to try and rebuild her army of killer robots.
With the Zephyr's time drive malfunctioning the team is forced to consider abandoning ship, while May takes Yo-Yo to Jiaying in hopes that their old adversary can help to restore her powers.
The time drive overloads, sending the Zephyr toward a time vortex that will erase the team from existence ... and trapping Daisy and Coulson in a repeating time loop.
Nathaniel Malick recruits a young John Garrett into his ranks, taking control of Afterlife and forcing Jiaying on the run. As S.H.I.E.L.D. tries to get her daughter Kora back, Daisy considers revealing herself to her mother.
Malick hijacks the Zephyr and kidnaps Simmons, hoping to force her to lead him to Fitz. Kora offers to join S.H.I.E.L.D. in remaking the new timeline, and Daisy goes rogue to try and beat Sibyl's algorithm.
The Chronicoms assault Earth directly, taking possession of Jemma and Deke and tasking Malick and his people with demolishing the Lighthouse and the survivors of S.H.I.E.L.D. inside.
When Fitz returns with a plan to restore the team's original timeline, one of the team must stay behind to make sure the Chronicom fleet is dragged along with them. While Simmons recovers her lost memories, Daisy finds herself in the fight of her life.
