Bizarre occurrences give Charlotte a sense of déjà vu, and she suspects Peter is hiding something. Franziska snaps when Magnus confronts her.

Hannah takes her obsession with Ulrich too far. The stranger asks Regina to deliver an important package. Martha is torn between Jonas and Bartosz.

Ulrich runs afoul of the law, Helge tries to dodge Egon Tiedemann, Claudia harnesses the cave's powers, and Katharina lashes out at Hannah.

Six months after the disappearances, the police form a task force. In 2052, Jonas learns that most of Winden perished in an apocalyptic event.

Clausen and Charlotte interview Regina. The Stranger takes Hannah to 1987, where Claudia has an unnerving encounter and Egon visits an old nemesis.

Jonas meets an ominous figure. While the kids comb the cave for answers, the adults gather in the bunker to share what they know about the travelers.

In 1987, Ulrich seizes an opportunity. The kids return to the cave with the time machine, and Jonas learns of a loophole that could change the future.

Martha meets the Stranger and learns his true identity. Claudia tries to prevent Egon's death in 1987. Hannah travels to 1954 to see Ulrich.

On the day of the apocalypse, Clausen executes a search warrant at the power plant as Jonas and Claudia use the time machine to connect past and future.

In 2019, Jonas emerges from the cave into a strange but familiar world: the town of Winden, reeling from the recent disappearance of a young boy.

Martha travels to 1888 to warn her friends about the 2020 disaster. Winden residents past and present search for their missing loved ones.

In 2020, a visitor delivers a warning to Claudia. The day before the apocalypse, Jonas begins to question Eva's motives.

Adam holds Martha captive in 2020. On the day of the apocalypse, an increasingly frantic Martha begs Bartosz for his help.

Across three centuries, Winden's residents continue their desperate quest to alter their fate and save their loved ones.