Orson Foxworth, the daring, unscrupulous president of the Great Blue Fleet, celebrates his return to New Orleans, after a long absence in Central America, by giving a dinner in the unique 1840 Room at Antoine's world famous restaurant. This dinner is ostensibly planned to present his charming niece, Ruth Avery, who has come from Washington for the Carnival festivities, to his friends in Louisiana, and to assure for her the romance which has hitherto eluded her; but it also serves as a springboard from which to renew Foxworth's own courtship of the beautiful widow, Amelie Lalande. At the dinner Amelie's daughter, Odile, spills a glass of red wine down the front of her white dress; and though the incident is passed off lightly, it is trafically recalled thirty hours later when Odile is found dead in her bedroom, with a strange pistol and an ambiguous note on the floor beside her. The first evidence points to suicide, but this verdict is challenged by Captain Theophile Murphy of the NEw Orleans police force. He insists that Odile has been murdered and that the ambiguous note is a clever forgery. His efforts to verify his suspicions become part of the pattern of an exciting tale.