A recently promoted police inspector (Gian Maria Volontè) kills his mistress (Florinda Bolkan), and then covers up his involvement in the crime. He insinuates himself into the investigation, planting clues to steer his subordinate officers toward a series of other suspects, including the woman's homosexuality husband and a student radical. He then exonerates the other suspects and leads the investigators toward him to prove that he is "above suspicion" and can get away with anything, even while being investigated. In the end, he confesses to the crime in front of his superiors - who refuse to believe him. Sure that he is safe, he recants his confession, and receives the approval of the police commissioner.