The singer Giannina Belloni is found shot. Since she was seen meeting with the concert master Friedrich Burger shortly before her death, both he and his wife are under suspicion. Burger flees and leaves his wife with their child. Belloni's murder remains unsolved. Ten years later: Maria Burger has been living with her daughter Eva, who is now 18 years old and has been trained as a pianist by the conductor Mobius. Mobius courts her mother and wants to marry her. But Maria pushes away his advances, mainly because she's still waiting for her husband to return. One day, Juan Perez arrives in Berlin with his famous tango-orchestra and shows an obvious interest in the Burger family. The reason soon becomes clear: Perez is Friedrich Burger!