Contains spoilers for this episode and earlier episodes.
In the original world's 1954, the cleft-lipped man meets young Tronte and gives him a bracelet belonging to Agnes. Accompanied by his younger and older selves, he also pressures an official into approving Winden's nuclear power plant. Hannah, living under Katharina's name, discovers that she is pregnant by Egon. His response exposes the limits of the future she imagined with him. Doris asks Egon for a divorce, while Hannah meets a young Helene Albers and leaves her the St Christopher necklace Egon gave her.
In the alternate world's devastated future, Jonas and teenage Martha meet her adult self in the bunker. The older Martha shows them the family names on the wall and warns that many will die in the approaching apocalypse. She urges Jonas to abandon hope of saving his own world and accept a life with Martha in hers. He refuses to settle for that answer. They return through the passage to 2019, where their growing attraction leads them to sleep together.
Meanwhile, the travelling Martha remains with Adam in the original world's future, expecting him to explain the origin he promised to reveal. Adam takes her to his former room and explains the purpose of her encounter with Jonas in the alternate world. He tells her that their son connects the two worlds and calls him the origin of the knot. The episode links this revelation to the cleft-lipped figures, whose actions have been securing the conditions needed for Winden's family history.