A young man is run over by a car at night. The Bremen commissioners Inga Lürsen (Sabine Postel) and Stedefreund (Oliver Mommsen) soon know that it wasn't an accident, but there doesn't seem to be a motive for the crime. When a short time later another young man is run over, the inspectors suspect that they are dealing with a serial offender . Traces at the crime scene lead to former drug addict Kristian Friedland (Moritz Führmann). But he has an alibi for the time of the murder. To the astonishment of the inspectors, his parents (Angela Roy and Rainer Bock) do everything they can to keep the investigation away from him. What is the family hiding?