Stanislas Borowitz is a divisional commissioner from the IGPN (:fr:Inspection Générale de la Police Nationale) who uses particularly expeditious methods to counteract the "ripoux" (French term for "corrupt cops"). Sent to Nice to struggle against the Mafia and enquire on a murder of a notoriously corrupt commissioner, he changes his identity into a thug named Antonio Cerruti to trigger a gang war between the two biggest local sponsors, Théodore Musard ("l'Auvergnat") and Achille Volfoni ("le Corse"), and discovers a police organization with the mafia of the town. But the corrupt police inspectors Rey and Massard, on the pay of Volfini, absolutely want to harm him.