Bruno and Katja Bassmann are on their way to the Côte d'Azur. During a stopover at a bistro, Katja disappears without a trace. Bruno is convinced that she has been kidnapped. But neither the police nor the embassy can help. Only the German-speaking taxi driver Aliya supports him in his search. They get caught up in a murderous network that leads straight to the underworld.
Lawyer Dominique Kuster can feel a professional success for herself when her underage client Stefan, the oldest of three foster children, receives mitigating circumstances. After the court hearing, however, she found out that the foster father Christian Hunziker had a fatal accident in a car. An autopsy reveals that it was murder. Someone has swapped the dead man's insulin for ineffective water. Christian's wife Martina comes under suspicion.