Monsieur Dufresne, a debonair traveler from Paris, meets the singer Zaza at a train station in the provincial town in which she has come to perform. Enchanted by her beauty, Dufresne returns to the theater night after night, without ever attempting to meet her. Wildly curious about her mysterious admirer, Zaza badgers the songwriter Bussy to bring his friend Dufresne backstage. Dufresne is strangely reluctant to meet the object of his desire, however, and when he finally does come to her dressing room, he is amused by her obvious attempts to ensnare him. Zaza's charms eventually win out, and Dufresne misses his return train to Paris and spends the night with his enchantress. Falling deeply in love, Zaza abandons her career and her partner, Cascart, for the pursuit of her romance. Meanwhile, Cascart accidentally discovers that Dufresne has a wife in Paris and, concerned for Zaza's well being, informs her of her lover's secret life. Furious, Zaza determines to confront the other woman and banish her from Dufresne's life. She goes to Paris where, while waiting to speak to her rival, Zaza meets Dufresne's little daughter Toto and comes to realize that Dufresne really loves his wife and daughter. Leaving Paris without ever revealing Dufresne's duplicity to his wife, Zaza confronts her lover with the truth when he pays her a visit the next night, and he walks out of her life. Zaza then pours her energy into the stage and, three years later, has become a star of the Follies. On opening night, Dufresne comes to see her perform, but Zaza sings a song of parting, forcing him to realize that theirs is a forbidden love. Dufresne leaves the theater, never to see her again.