Lamenting Thebian women are waiting for the men to come back from war. God Jupiter is attracted to one of them: Alkmene. He goes to earth and tries to seduce her as himself: an old man. Failing in this, he disguises himself as Amphitryon (Alkemene's husband) and tries again. Next morning Amphitryon and his men come back from war; he suspects adultery and wants a divorce. Jupiter's wife Juno now also comes to earth and clears things up.
Charley Wyckham and Jack Chesney pressure fellow student Fancourt Babberly to pose as Charley's Brazilian Aunt Donna Lucia. Their purpose is to have a chaperone for their amorous visits with Amy and Kitty, niece and ward of crusty Stephen Spettigue. Complications begin when Fancourt, in drag, becomes the love object of old Spettigue and Sir Francis Chesney.
The operetta composer Robert Ottmar is fascinated when he discovers a picture of a young lady in a newspaper. The beauty's mere countenance inspires him to write a new operetta, which is very successful. Ottmar learns that his beloved is called Gloria and is the daughter of a general manager from Nice. In order to find out whether Gloria corresponds to his ideal image in reality, he hires himself out as a valet in her father's villa - incognito, of course.