Tongues start to wag after a famous Parisian music hall dancer is rushed to hospital after being found poisoned by arsenic at the Concert Mayol.

Charming, charming but unstable, Rudy is married to Lydia. He dreams of becoming a famous painter. His father-in-law offers him a contract: if he stays in the same job for at least two months, he can devote himself to painting. Under the name of his friend Ravot, Rudy is hired to teach gymnastics at a girls' college. Things soon get complicated. The jealous Lydia, who plays student, keeps an eye on her husband. The headmistress glares at him, and the arrival of the real Mme Ravot doesn't help matters. The contract is almost not honored, but as in the best comedies, everything works out.