The whole city is rushing to the circus to see the deadly act of the famous masked artist, the mysterious Mr. X. Among the guests is a rich widow, Countess Palinskaya, for whom any man is ready to perform a feat. But only the mysterious X is able to ignite the flame of love in the heart of the inflexible Countess...
A mysterious man under the name Mister X performs in the circus, playing violin on a chair suspended in the air by ropes. His breathtakingly sad melodies reflect his internal turmoil - he's in love with a noble lady and this relationship is frowned upon in their society.
Karoline and her daughter Marlene do not know that their long-absent son and brother Franz has been killed in the war. Franz's soldier friend Alwin goes to tell them the news, but in the event he can't bring himself to tell them the truth.
