The middle-aged Marquis de Sade arrives at his ancestral estate of La Coste, having escaped incarceration. In the theater at the castle, he meets his uncle, the Abbe, who persuades him to stay to watch an entertainment that has been prepared for him. The play is a parody of the Marquis' parents haggling with M. and Mme. Montreuil over the prospective marriage of their children, leading to a flashback in time to the actual negotiations.