Dr. Jan Diffring practices as a doctor on the Reeperbahn and has the full trust of the people who work and live here. He would never give the police information and look the other way when someone is in need. As he is on the Reeperbahn in the early hours of the morning, he comes to the aid of a young woman who is being beaten up by a few men. He has no idea that this robbery is related to sex parties that are organized for a clientele of rich businessmen and in which his brother Klaus is involved. Although he is a respected gynecologist, he has high debts and is forced to make rich married ladies who want to have an unwanted pregnancy eliminated by him compliant for these parties. When the young sailor Hein turns to Jan and asks him to help him find his fiancée Margot, who has disappeared without a trace, the situation escalates...