Serge (Serge Gainsbourg) is sent to France by New York mobsters to secure a shipment of heroin. The supplier in France is being ripped off by a middleman who has gone into business for himself. His first order of business is to wipe out the customers of a drug house who have bought their drugs from a rival dealer. After slaying the bunch, with the help of a maniacal hippie (Paul Nicholas), he is off to Paris. Someone tips off the rival gang of Serge's arrival and he is met at the airport by two thugs. A pretty woman he met on the plane (Jane Birkin) finds him slumped in his car and takes him home with her. The two soon are entwined in a passionate embrace. Emery (Curt Jurgens) is the French drug kingpin who along with Serge is sought by the inspector (Gabriele Ferzetti).
by Dan Pavlides synopsis