Impasse des vertus (1955)

Monique comes back home after several years in a sanitarium.Her guardian, Gilbert,who owns a small cafe, tells her that her mom,Denise,always a widow, lives with a shady man ,Eugene.The young girl realizes that her mom's partner is a selfish man who woos her assiduously.Gilbert's bar is a place where disreputable persons meet.All of them obey a mysterious guy, Fanfan.Eugène becomes part of his gang and kills a policeman.