Just now, 17-year-old Stefan Hunziker is happy about the mild judgment that Dominique Kuster brought him out for a fight and now his father has a fatal accident with the car. The police find out that there was only water in the insulin capsule of the diabetic Hunziker - so it is murder. The victim's wife quickly becomes the main suspect. Hunziker had a mistress who was expecting a child from him. A clear motive for murder for Martina Hunziker. However, Borchert does not believe in their guilt and begins to investigate.