Die-oder Keine plot
Prince Michael of Marana falls head over heels in love with the famous singer Eva Petri, the great star in the world of operetta, in Berlin. The love is mutual, but there are pirates on the coast, such as his older cousin Prince Wenzel who also has his eye on the throne. When Prince Lothar of Marana suddenly dies, Wenzel immediately flies back to Marana from Berlin to prevent Michael from becoming his successor and seals the border hermetically. However, Eva has been invited by Wenzel, so she comes up with a plan to get Michael to Marana unseen.