Observing staunch moral attitudes, professor Traugott Nägler, his wife Marianne, and their swarm of children life a happy and idyllic life in a small town. But when their oldest daughter Atlanta inherits a house in Montevideo that belonged to the deceased sister of the professor, the family′s life is about to change dramatically.

In the face of two world wars, Professor Prätorius, a philanthropist and a surgeon, wants to exterminate the one danger to mankind, the microbe of stupidity, as he states in a spontaneous lecture to his male and female students. When he tries to help a pregnant girl he gets involved more and more in her life and is forced to marry her.

English Lord Arthur Cavershoot is a passionate Napoleon scholar who badly neglects his wife Josephine for his obsession with the French emperor. When the cranky historian travels to a Napoleon conference in Paris, his smart spouse secretly follows him. Unnoticed by her, the city of love threatens to spark a romance between Arthur and a chorus girl.

The story is one of the classic operetta stories with a young princess destined to marry a king whom her mother tries to enforce while the young woman tries to escape her fate.