Alfred Walch lives in Krems with his wife Anna and his three children Alexandra (17), Daniel (19) and Sonia (6). On Alexandra's 17th birthday, the town festival takes place in Krems. Two reasons to celebrate. The usual arguments between teenagers and parents about when to be home are inevitable. She persuades her father to let her stay longer. But Alexandra doesn't come back at this time either. The parents' initial anger towards their daughter gradually turns to worry and panic when it turns out that the girl was last seen in the harbor area, a shady neighborhood, where she had a violent argument with her supposed boyfriend, Moritz. When there is still no trace of Alexandra the next evening, Inspector Lenz and his colleague Lisa are called in. A large-scale search is launched without success. Alexandra remains missing...