Bresson adapted this film from Georges Bernanos's Nouvelle Histoire de Mouchette. Peasant girl Mouchette (Nadine Nortier) has an extremely hard time with her life as an adolescent: her mother (Marie Cardinal) is very ill in bed, her father (Paul Hébert) is an alcoholic, she also has a baby to look after, her teacher bullies her, and her school companions aren't companions at all and ignore her. It's hardly surprising that she hides away from them, although she doesn't help that she throws clods of earth at them from her hiding place. And she has no chance in the love stakes either: even when a young guy appears to be flirting with her on the dodgems her father reins her in.
Dialogue is kept to a minimum here, and anyway of course we have the Bressonian trademark of non-actors, and words and faces without expressions. This is filmed in Vaucluse, often in a café where the server automatically serves a wine or gin to a customer, the customer drinks, the glass is filled several times, payment is made, the customer leaves: frequently without a word by anyone. Her mother's last words are to stay away from drunkards: not an easy thing to do, as she's already discovered.
Lost in the forest when the drunken poacher Arsène (Jean-Claude Guilbert) finds her, he wrongly believes he's killed Mathieu and wants to use her as an alibi. She agrees and is initially very impressed with his friendliness, although he later rapes her. After her mother's death a shopkeeper calls her a slut, an elderly woman gives her a funeral dress and a shroud, but she uses these to roll down a slope three times, the third of which brings success when she finishes in the river. Again, Mouchette's torments have been interpreted as stations of the cross.