Beautiful Wanda Schonbern waltzes with a handsome masked stranger at her first ball. The magical sounds of the waltz carry them towards their dreams. The charm of youth and naive admiration for the light attract admiring glances to the girl. Richard Melton is ordered to portray the Russian Tsar at the Viennese costume ball. There he meets a beautiful girl in a mask. The magical sounds of the waltz captivate young people to a wonderful dream. But both have something to hide... At the Viennese court, political intrigues are intertwined with love affairs, and Wanda is inexorably drawn into their web. The attention of the highest persons brings trouble to her, and the mutual feeling that flares up between the young people causes the fierce jealousy of the influential princess, who decides to destroy the girl...