Spur des Blutes.

The chief inspectors Max Ballauf and Freddy Schenk are called to a canal on the outskirts of the city. A 19-year-old drug addict has been murdered. It quickly turns out that the victim, Lara Krohn, became a street prostitute because of her addiction. Her best friend, Kim, who is the same age, suspects that Lara was killed by a customer.