Louise (Danielle Darrieux) is an aristocratic woman of "Belle Époque" Paris, married to André (Charles Boyer), both a count and a high-ranking French army general. Louise is a beautiful, but spoiled and superficial woman who has amassed debts due to her lifestyle. She arranges to secretly sell her costly heart-shaped diamond earrings, a wedding present from her husband, to the original jeweler, Mr Rémy (Jean Debucourt). Relations between Louise and André are companionable, but they sleep in separate beds, have no children, and André has a secret mistress, of whom he has recently tired. Louise disguises the disappearance of the earrings by pretending to have lost them at the opera. The search for them eventually reaches the newspapers ("Theft at the Theatre") which in turn prompts Rémy to go to André and "discreetly" offer to sell them back. He accepts cheerfully and, rather than confront his wife, coolly gifts the earrings to his mistress, Lola (Lia Di Leo), whom he happens to be seeing off permanently to Constantinople.