When the local police inspector was found dead in a prostitute's house, police division commissioner Stan Borowitz is sent to investigate the situation. Posing as the prostitute's long-lost brother "Antonio Cerruti," he discovers a mare's nest of police corruption. In fact, in this comedy thriller the whole town is corrupt. If they were closely examined, Stan's methods for pursuing this investigation might embarrass the police. For instance, he drives into a criminal's house in a fancy, expensive race car. In another incident, he callously blows up a casino owned by Musard , one of the town's crime bosses. On that occasion, he first forces Musard to remove his clothes, and the poor criminal watches his casino explode from across the square while standing naked in a phone booth. Meanwhile, Stan seduces the lovely Edmonde.

Campana, a commissar at the drugs bureau of Paris police gets an undercover job in Nice to catch an Italian-French mafia boss. As he slips into the identity of a gangster's brother, who was already killed, he has to play the role of a loving husband with child - something that is not so easy for a confirmed single like Campana. Unfortunately American killers chase behind the Nice mafia clan too, in order to get control of French drug trades to USA.