Parisian Séverine is married to a young doctor and loves him deeply, but not sensually. Her fantasy life is rich in sexually masochistic daydreams and when Séverine hears that a friend devotes part of her day to working in a bordello, it stirs a desire in Séverine to do the same. She joins a group of women in a bourgeois house and encounters a number of men in imaginative situations. Since Séverine is home every day by 5 o'clock, her husband knows nothing of her secret. However, the situation turns ugly when one of Séverine's steady customers, a handsome mod gangster, falls seriously in love with her and insists that she leave her husband.