Paris, 30's declared professional rivalry between two stars of the musical, Yvonne and Gaby leads to dire consequences. Yvonne's body is found in the theater. Gaby's future is threatened against the judgment to which it is subjected, with a probable prison sentence.
Lieutenant Varnière, responsible for discovering the cause of the death of two officers in Algeria, unmasks the assassin in the person of a Russian who lives with three women. He falls in love with one of them and runs away with her while the Russian is killed by a devoted servant.
