A psychological novel about a family shaken by the realization that their tenant is a dangerous criminal. Lukas Hartmann forges a sensitive link between a portrait of a woman in crisis and a psychological study of a criminal. When their son Sebastian moves out, Margret and Gerhard Sandmaier are left behind. Margret in particular finds the empty house oppressive. Gerhard has his work as a history professor, but Margret’s part-time job at a bookshop and the German lessons she gives for refugee children are not enough to satisfy her. And Sebastian, having fled the nest, maintains a painful distance. The Sandmaiers decide to rent out the annex where their son used to live. They soon find a suitable tenant: a young bicycle mechanic, unobtrusive, polite, taciturn. But Margret begins to develop suspicions when stories hit the headlines about a man attacking young women with a knife.