Young Monique leaves the preventorium where Doctor Delaunay has lovingly cared for her. A painful return. Her mother Denise lives with Eugène, a handsome, disreputable young man who's easy to please and, on occasion, won't hesitate to steal. He hangs around Monique, excited by her freshness, until the day he is shot on suspicion of the disappearance of a mobster. Monique is reunited with Dr Delaunay, much to the satisfaction of her guardian Gilbert, known as Patte-en-moins, owner of the local bistro.
