Hannah Kahnwald (born Krüger) is the recently widowed wife of Michael and mother of Jonas. From a young age, she had an obsession with Ulrich Nielsen and in 2019 has an affair with him. Hannah works as a masseuse, counting Aleksander Tiedemann, director of the Winden Nuclear Power Plant, among her clients.
In 1986, Hannah was a 14-year-old with an unrequited crush on Ulrich, then a student at the high school. ("Past and Present") Ulrich was already romantically involved with Katharina Nielsen, provoking jealousy in Hannah when she sees them holding hands. Agitated after seeing them having sex in the locker room, she tells her father, Sebastian Krüger (who is just named in the credits) and then police officer Egon Tiedemann, that she saw Ulrich raping Katharina, leading Egon to arrest him. ("Truths") Later, she suggests to Katharina that it was Regina Tiedemann who made the accusation, leading Katharina to attack Regina. ("Everything Is Now") A young stranger rescues Regina by brandishing a gun; he gives her the name Aleksander Köhler. Hannah later observes him burying a bag in the woods containing a gun and passport, and retrieves the bag secretly.
One night, Hannah and her father stop when they encounter Jonas Kahnwald from 2019 standing in the rain. They offer him a ride, warning about acid rain because of the Chernobyl accident, but he declines. ("Sic Mundus Creatus Est")
In 2019, Hannah, widowed by Michael Kahnwald's suicide, is carrying on an affair with Ulrich, himself married and the father of three. When Ulrich's son Mikkel goes missing, she tries to see him at the Winden Police station, but he turns her away. ("Lies") Later, she brings food to the Nielsens' house as an excuse to see him, making Katharina suspicious. Ulrich attempts to break off the affair, but Hannah refuses. ("Truths") Katharina later confronts Ulrich and forces him to admit the affair. ("Crossroads") When Ulrich fails to come home, Katharina goes to Hannah's home, thinking Ulrich must be there, and berates her. Hannah falsely tells her that she ended things with Ulrich, and that he had planned to leave Katharina because he loved her. ("Everything Is Now")
After the confrontation with Katharina, Hanna takes the bag she had taken from Aleksander, now a massage client of hers. She speaks bitterly about her unhappy life and then presents the bag to blackmail him, telling him she has secured its incriminating contents elsewhere. She does not want money; rather, she will keep quiet if Aleksander uses his resources to destroy Ulrich's life. ("Everything Is Now")