A comedy of confusion in aristocratic Vienna at the turn of the 19th into the 20th Century: The young Bohemian Countess Antschi Dorival trades places with her friend Martina, because she wants to become an actress and applies as such at the city theatre under a false name. And so, Martina attends the Vienna Opera Ball, posing as the countess. Because of their striking similarity to one another, Martina is confused with the impostor Sonja Lubomirska, who shortly before stole a necklace belonging to the wife of Archduke Johann Sylvester.