An American couple drift toward emptiness in postwar North Africa.

Good dope is becoming rare in the North of Paris. Drugstores are being raided by junkies and gangs are nervous, fighting each others: the 'Viets', the 'Blackies', the 'Arabs', the neo-nazis 'Justiciers' and some mean gays. Vincent (Daniel Auteuil) is the good cop coming from Marseilles where he was a gangster. He's a soft method guy but also kicks assses hard and throw lethal dialog lines when needed. With the precious help of 'l'Arbalète'* (Marisa Berenson**), a tox' prostitute ex-member of Vincent's former gang, he will try to put order in that mess. There's also a violent and racist cop (Marcel Bozzuffi), Algeria veteran with hard methods, whose role could be more than to protect and to serve.