In our time, in France, in an imaginary place.
José Fabri, a middle-aged gangster, is being chased by the police.
Rose, a chemist, wants to employ an elderly woman to take care of her house.
She puts an advertisement in the local paper.
Holed up in his hotel room, José spots the advertisement. He decides to dress up and become Joséphine in order to get the job which will allow him to escape Captain Popol's clutches.
It's true that the police would never go looking for an elderly woman doing housekeeping, cooking and all the rest in a bourgeois house, surrounded by two young women who are bound to be perfect little angels, with the best manners in the world...