Sophie, a quiet and shy maid working for the upper-class family Lelievre, hides her illiteracy under the cloak of a perfect household and obedience. She finds a friend in the energetic and uncompromising postmaster Jeanne, who encourages her to stand up against her bourgeois employers. Things start to escalate as the Lelievres find out that Sophie can't read and has brought Jeanne into their house against their wish.