On the death of the famous singer Maria Malibran, Countess Merlin retraces the main lines of the unusual destiny of this young woman entirely devoted to her art.

Two country sisters are rivals for the love of the doctor. He marries one, but regrets it and is rescued by the other.

Micheline Chevassu is a young, naive woman living in an orphanage. Through classified ads, she has a date with an unknown man. She escapes from the orphanage to go to it, dreaming of the Prince Charming. But comes Nicolas Rougemont, an unattractive middle-aged man... He pretends not to be the author of the letters, who could not come...

In the elevator of two large Parisian buildings, a telegraph operator discovers the body of an elderly woman, Madame Mathieu, the owner of both buildings. Boucheron (Lucien Baroux), the local superintendent, is dispatched to investigate, along with his rival, Inspector Lambert of the "Sûreté" (Jacques Baumer). To solve the enigma, they scour staircases and corridors, visiting every floor of both buildings, courtyard and facade. Their gruff rivalry allows them to complement each other in discovering who committed the crime among a gallery of characters, humble or rich, who all have something to be ashamed of... A rare, fast-paced, picturesque comedy set against the backdrop of a police mystery.