Miss Pettigrew, an approaching-middle-age governess, was accustomed to a household of unruly English children. When her employment agency sends her to the wrong address, her life takes an unexpected turn. The alluring nightclub singer, Delysia LaFosse, becomes her new employer, and Miss Pettigrew encounters a kind of glamour that she had only met before at the movies. Over the course of a single day, both women are changed forever.