Maurice (Michel Simon) is a married cashier who meets Lulu (Janie Marèze), a streetwalker. Their chance meeting results in Maurice falling in love with Lulu. She, however, is in love with her boyfriend-pimp, Dédé (Georges Flamant). Together, Dédé and Lulu plot ways to get Maurice to give cash to Lulu, mostly at the urging of Dédé.
Source : Wikipedia