Contains spoilers for this episode and earlier episodes.
In 1921, a young Noah helps excavate the cave passage before killing his fellow worker for losing faith in Adam's prophecy. His older self consoles him afterward, while Adam insists that the approaching apocalypse must happen and orders Noah to recover the missing pages of a notebook. The murdered worker's name remains unspoken. In 2020, six days remain before the disaster, and Winden is still searching for the people who vanished months earlier.
Clausen arrives to reopen the missing-person cases with Charlotte Doppler. Katharina searches the caves for Ulrich and Mikkel, while Martha begins looking through her father's files and ends her relationship with the increasingly secretive Bartosz. At the Kahnwald house, Hannah is alone with a gun when the adult Jonas arrives. He proves that he is her son through childhood memories and a scar, then explains that his younger self is trapped in the future.
In 2053, that younger Jonas lives among Winden's ruins and listens to Claudia's recordings about the catastrophe of 27 June 2020. The adult Elisabeth rules the survivors and forbids entry to the dead zone, enforcing the restriction with public executions. Jonas refuses to accept her promise of paradise. He crosses the barrier and enters the ruined power plant, where he discovers a shifting black mass matching the phenomenon described on Claudia's tapes.