The ballet pupil Camilla Favier tells the author Jean Mayol that she had learned all lines of the main character in his new play. When the stage manager announces that the leading lady is sick, Jean suggests that Camilla could replace her this evening. Camilla makes a huge success, and she and Jean fall in love. Jean introduces her to his friend, the painter Paul Rich, who wants to make a painting of her. While she is in his atelier, Jean gets a love letter from Yvette Simon, the wife of a rich rentier, asking for a rendezvous in the wood. In Jean's empty apartment Camilla finds the letter and is devastated. In revenge she reveals the secret love story for Mr. Simon and his guests at a big party. Later she finds a new love message from Yvette Simon. She brings it to Mr. Simon, who gets furious, grabs a pistol and goes to Jean's apartment. Camilla repents and rushes away to warn Jean and Yvette.