Season synopsis
Contains spoilers for this season and earlier seasons.
Jonas Kahnwald returns to school in Winden after treatment following his father Michael’s suicide. The disappearance of a local teenager has already unsettled the town when eleven-year-old Mikkel Nielsen vanishes near the caves beneath its nuclear power plant. His father Ulrich, a police officer, searches for him while another boy’s body appears in the woods. The dead child is eventually identified as Ulrich’s brother Mads, who disappeared in 1986. The investigation connects the Kahnwald, Nielsen, Doppler and Tiedemann families through secrets their parents have kept for decades.
The caves contain a passage between 2019, 1986 and 1953. Mikkel has reached 1986, where nurse Ines takes him in; he will grow up as Michael, marry Hannah and become Jonas’s father. Rescuing him could therefore erase Jonas’s own existence and changes Jonas’s understanding of his attraction to Mikkel’s sister Martha. Ulrich travels farther back, to 1953, and attacks the young Helge Doppler in an attempt to prevent the missing children’s deaths. Helge survives, and Ulrich is arrested. In 1986, the adult Helge is helping the priest Noah abduct children for a prototype time machine whose failed experiments send their bodies into other years.
The stranger guiding Jonas reveals that he is Jonas himself, thirty-three years older. He plans to destroy the passage using a device built by clockmaker H. G. Tannhaus, but refuses to release his younger self from the bunker where Noah has confined him. Meanwhile, the elderly Helge tries to stop his younger self in a car crash, killing himself instead. When the stranger activates his machine, a rift links the imprisoned Jonas with Helge as a child. Their hands touch, sending Helge to 1986 and Jonas into a devastated future Winden, where armed strangers take him captive.