As children, Zouzou and Jean are paired in a traveling circus as twins: she's dark, he's light. After they've grown, he treats her as if she were his sister, but she's in love with him. In Paris, he's a music hall electrician, she's a laundress who delivers clean underwear to the hall. She introduces him to Claire, her friend at work, and the couple fall in love. Jean conspires to get the show's star out of town and for the theater manager to see the high-spirited Zouzou perform. When Jean's accused of murder and Zouzou needs money to mount his defense, she pleads to go on stage. Her talents may save the show, but can anything save her dream of life with Jean?