In the postwar Paris, the accompanist pianist Maurice Martineau is a jealous man from the upper class married with the ambitious singer Marguerite Chauffournier Martineau, most known by her artistic name Jenny Lamour, a woman with past from the lower classes. When the lecher but powerful Georges Brignon harasses and invites Jenny for dinner promising a role in a film, Maurice goes to the restaurant and threatens Brignon. A couple of days later, Jenny tells Maurice that she is going to visit her grandmother in another town. However, her husband finds a piece of paper hidden in the kitchen with Brignon's address. Maurice goes to the theater to have an alibi and heads to Brignon's manor during the show with the intention of killing the old man. However, he finds Brignon's house open and the man dead on the floor. When he leaves the crime scene, his car is stolen and Maurice has to walk back to the theater. Meanwhile, Jenny arrives in the house of the lesbian photographer Dora Monnier, who is an old friend of Maurice and has a crush on Jenny, and tells Dora that she has just killed Brignon. But Jenny notes that she had forgotten her fur on the couch in the living room of Brignon's house and Dora takes a cab to retrieve the stole. Inspector Antoine is assigned to investigate the case and sooner he visits Jenny, Maurice and Dora to check their alibis for that night in the beginning of his investigation.