Duca Lamberti is a medical doctor who has just been released from prison, where he has spent three years for having practised euthanasia. Duca is asked to help an acquaintance's son with alcohol addiction and discovers the issue has been brought on by guilt; some time previously he ignored the plea for help of a prostitute he had picked up and who was found murdered by the roadside. Duca will find himself helping the police and uncovering a complex ring of prostitution, pornography and crime.