Based on a story by Michel Linsky, "Adieu, Mascotte" revolves around an artist's model named Mascotte (Harvey) who ekes out a hand-to-mouth existence in the Parisian art colony. In dire need of money to finance a friend's operation, Mascotte auctions herself off at an artist's ball. She is "bought" by a novelist named Jean (Igo Sym), who merely wants to teach his flirtatious wife a lesson. Discreetly keeping his distance, Jean persuades Mascotte to pose as his mistress so that his wife will become jealous and return to his arms. Of course, things don't go as planned.