When the dead body of an asian child is discovered in a lateral river channel in Duisburg, chief inspectors Schimanski and Thanner have to investigate the case. The autopsy shows that the victim had typhus, since this could lead to a dangerous epidemic, Schimanski and Thanner had to find out more information as quickly as possible, while under pressure from the press and the public.

Dr. Waldorf, a physician is found murdered in his office. Suspect is Baumgarten, the director of the waste recycling company on whose behalf several of the doctor's patients, had regularly shipped cargoes of toxic waste, is also killed. The motive seems clear: a cover-up of criminal environmental pollution on a large scale. But who were the perpetrators?

Schimanski fears for the life of a child and ends up playing a dangerous game.

Jochen Bähr, department head in a pharmaceutical company, is found shot dead in his boat early on a Sunday morning. At the crime scene is his young son Thomas, who is in shock and unable to speak. Schimanski, who needs the boy's statement, tries to break his encapsulation. He has initial success - then Thomas is kidnapped under the eyes of the inspector.

Schimanski is on a fishing holiday in an idyllic spot not far from Duisburg. There he witnesses a strange event: the veterinarian Karl-Heinz Ascher is found dead on his wedding day - hanged from a tree. Silke Faber, the bride, daughter of the richest farmer in town, is at a loss and asks Schimanski for help in solving the death.