Author and actor Erich Remberg learns from his producer that his musical has been panned by the Viennese critics, who seem to prefer more romantic and less sexy productions these days. In order to find the inspiration to write an operetta, Erich goes with his friend Peppi to the von Keller castle in Tyrol. They are greeted by the eccentric Baron von Keller, who proudly shows them nonexistent antiques that only he can see. While investigating some strange noises he's heard in the middle of the night, Erich meets von Keller's daughter Loni, who is also curious about the room. She shows him a painting representing the Napoleonic invasion of Austria and tells him of her great-grandaunt, who scandalized the family. Erich imagines the scene with Loni playing the role of the baroness of the von Keller castle and himself as her French lover: Back in 1809, a French colonel insists on quartering at the von Keller home, and Loni dines with the invaders with reluctance.