Melanie notices a car being driven without a licence plate, and by an underage boy.  She pursues the fleeing vehicle, but the chase ends at the harbour where the escape car plunges into the Elbe. It quickly becomes clear that there’s no chance of any survivors.  Melanie has to confront the boy’s distraught parents, Angelika and Bernard, who blame her for the death of their son. Meanwhile Boje and Franzi learn that Tim had major problems at home. Was it suicide committed by a frustrated teenager? However, a surprising turn of events occurs when the car is salvaged and no-one is found inside. Tim has apparently only faked the accident to teach his parent a lesson. Shortly afterwards when a demand for ransom arrives, the police are again at square one with their investigations. Who has put Tim at the mercy of their power? The search for the boy proceeds at full speed. But the police still do not know that Tim’s life is in danger.