Rosé and his opera troupe travel by ship to Monte Carlo. Mario Delmonti, the tenor, finds Carla hidden in his cabin, and helps her returning to Europe. Arriving in Monte Carlo they find the opera director hard to convince. Confident in Mario's exceptional voice they don't give up, even if they have to perform a parallel Tosca in front of the Opera house. First film Martha Eggerth and husband-to-be Jan Kiepura made together.