Based on a story by Michael 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 (Harry Halm), 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, and before long Jean and Mascotte have fallen in love.