In Vienna, Anna von Ziska is the beautiful daughter of an upper-class family that has lost its wealth. Prince Augusto notices her in a chance encounter and immediately falls in love with her. Anna, however, is unapproachable and would have remained so had it not been for her parents' plight. She at first suspects that the prince sees in her simply another one of his many affairs. Though she will have none of this, she does see in him an opportunity to help her parents. Consequently, she proposes to play the role of the prince's mistress in public for his esteem, but in private to remain platonic.