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.
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.
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.
Six months after the disappearances, the police form a task force. In 2052, Jonas learns that most of Winden perished in an apocalyptic event.
Ulrich runs afoul of the law, Helge tries to dodge Egon Tiedemann, Claudia harnesses the cave’s powers, and Katharina lashes out at Hannah.
Ulrich questions a frail and frightened Helge in the nursing home. Jonas searches for Mikkel, but the stranger warns him about meddling with the past.
Ulrich looks to the past for answers and dredges up disturbing family secrets. Armed with new tools, Jonas probes the cave’s murky depths.
Bizarre occurrences give Charlotte a sense of déjà vu, and she suspects Peter is hiding something. Franziska snaps when Magnus confronts her.
When a grim discovery leaves the police baffled, Ulrich seeks a search warrant for the power plant. A mysterious stranger checks into the hotel.
In 2019, a local boy’s disappearance stokes fear in the residents of Winden, a small German town with a strange and tragic history.
Claudia reveals to Adam how everything is connected — and how he can destroy the knot.