Agnes, a lonely teenage girl, and her father befriend an escaped convict, named Joseph, who arrives at their farm in Brittany, France. When Joseph develops an attraction to Agnes, her father threatens to break up the union.
In World War II, the widow Barny sees the Italian soldiers arriving in occupied Saint Bernard while walking to her job. Barny lives with her daughter and works correcting tests and feels a great attraction toward her boss Sabine. When the Germans arrive, Barny sends her half-Jewish daughter to live on a farm in the countryside and finds that Sabine's brother has been arrested and sent to a concentration camp. The atheist Barny decides to baptize her daughter to protect her and chooses priest Léon Morin to discuss with him themes related to religion and Catholicism and Léon lends books to her. Barny converts to Catholicism and becomes closer to Léon, feeling an unrequited desire for him.
Eloi is a twenty-year-old secondhand goods dealer who does his job without particular enthusiasm. He has a girlfriend, Nénette, but immature as he is, he feels just as happy in the company of Fortunée, his young sister, whose little girl's games he shares as often as he can. The three of them live with Eloi and Fortunée's grandmother, nicknamed by all the "Queen of the Flea Market". In possession of a mirror of Venice, Eloi decides to present it to Dormoy, an antique dealer who keeps up shop in the fashionable districts of Paris. On that occasion Eloi meets and falls in love at first sight with Dormoy's rich mistress. The latter, half-moved, half-consenting, does not discourage him.
Mario di Donati, a deserter from the Italian army, lives in Paris under a false name with Germaine, his French lover. When the latter learns about his hidden past, she feels hurt by Mario's lack of trust in her and she distances herself from him. In despair, Mario surrenders to the law but, at the time of trial, he runs away to join the woman he loves.
