A small village in the Bergisches Land - after a village festival, Karla Petersen, a young woman, is murdered on the way home. Helen Dorn, whose father is still in a coma, takes on the case.

Helen Dorn herself becomes a case for the police when she is accused of the murder of her boss Mattheisen. A surveillance for illegal arms trafficking gets out of hand.

Chief Inspector Helen Dorn is still feeling the effects of the murder of her boss Mattheisen. A new case leads them from North Rhine-Westphalia to Hamburg.