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.

In 1954, a missing Helge returns, but he'll only speak to Noah. In 1987, Claudia brings the time machine to Tannhaus, and Egon questions Ulrich again.

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.

Armed with a plan to prevent the apocalypse, Jonas travels to 2019. During the Nielsens' anniversary party, Ulrich sneaks off with Hannah.

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.

Charlotte and Ulrich try to piece together what happened in the bunker. In different times and worlds, Jonas and Martha work to gain each other's trust.

Martha and Jonas travel to 2052 and get a glimpse of a grim future. In 1954, two residents of Winden go missing, and Hannah receives surprising news.

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.

Claudia reveals to Adam how everything is connected — and how he can destroy the knot.