Because of his failing health, Monsieur Henri (Claude Brasseur) can no longer live alone. Particularly distrustful, he nevertheless ends up accepting his son Paul's suggestion to rent out a room in his Parisian apartment. But Henri has a devious plan. Choosing as his lodger the attractive Constance (vivacious newcomer Noémie Schmidt), a student who has just moved to Paris, he offers her free lodging on condition that she does everything in her power to drive apart Paul (Guillaume de Tonquedec) and his wife Valérie (the fabulous Frédérique Bel), whom Henri despises. What ensues is classic farce material with a whirlwind of uproarious misunderstandings and awkward situations. And slowly, the wry cynicism of the beginning makes place for the sweet and uplifting message at the core of the film: follow your dreams and don’t waste a minute!