The life of a weak-willed man is thrust into a downward spiral by the scheming of his manipulative girlfriend and her mother.

To inherit his uncle's hotel and restaurant, a naive and simple man must pass his primary school exam.

Madeleine Lebeau, a woman who charges for her easy virtue, has a plan that has some of her customers paying more than others; she tells them she is pregnant and, to avoid complications, the men pay her money and don't hang around for the birth. Yves Furet, a shiftless gambler, who not only encourages her in her business ventures but is also her fiancée, shares the fruit of her non-labor. She latches onto a wealthy widower, Henri Vilbert, who throws her a curve-ball when, after she tells him she is pregnant, he is overjoyed as he has fallen in love with her and is looking forward to becoming a father. She plays along for a while, but becomes ashamed when she sees how Vilbert is devoting his whole life to a child that she isn't carrying. She fakes a miscarriage and his kindness makes her feel guilty and she confesses, but he doesn't believe her. So she tries another plan.

Smalltown confectioner Lespinasse, hopeful of being reelected as chief councillor, is opposed by Darcepoil, the local druggist. Darcepoil arranges for the incumbent's defeat by having Pantaflon, a nightclub singer, lure him to the nudist camp on the Isle of Levant, where Lespinasse is photographed surrounded by half-naked women. At home, he is berated by his wife and thrown out of office; but he returns to Levant with the penitent Pantaflon and is welcomed by the nudists and voted camp president. His forgiving wife follows him and herself becomes a nudist.