Le diamantaire Jeffries a été assassiné dans la somptueuse demeure qu'il occupait à Auteuil. Des brillants ont disparu. Le crime a été commis alors que seuls se trouvaient dans la maison, un vieil ami de la victime, sourd et impotent, la cuisinière et la femme de chambre. La sagacité de l'inspecteur Grey permet de résoudre l'énigme.

A young man is a collector of feminine conquests. One morning, leaving one of his mistresses he is addressed by one of his past flirts. As revenge, she denounces him later to the police as the murderer of her fiance who was found dead the same morning. With the help of his mistresses and some new ones he makes on the road, the young man goes in search of the man he thinks is the killer, then his blond consort with whom he fell in love at the first sight the evening before.