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.
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.
Peter gets a shock. Jonas learns the truth about his family, but there are more surprises still to come. Helge makes a sacrifice.
Ulrich runs afoul of the law, Helge tries to dodge Egon Tiedemann, Claudia harnesses the cave’s powers, and Katharina lashes out at Hannah.
In 1953, the disfigured bodies of two boys are exhumed at a construction site, the future location of Winden’s nuclear power plant.
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.