Vénéneuses.

An aging gangster (Jean-Pierre Mocky) escapes from prison and is taken in by a very beautiful blonde who asks him to kill her uncle (Richard Bohringer) because he guards her money but prevents her from using it. She asks the gangster to kill him and that way she won't turn the gangster in - she knows he's escaped. The gangster prepares to kill the uncle, except that he realizes he's a very good guy. He becomes friends with the uncle. He won't kill him and will simulate the murder.