An old friend asks Amory Ames to find a piece of jewelry that went missing during a dinner party. Amory agrees to help, planning to set a trap for the kidnapper during a masquerade ball, to which he is probably invited. However, during the masquerade, it is not a theft that occurs, but a murder... The nephew of Amory's friend is found shot dead. Who is the criminal? Who could stop a good-natured young man, whose only shortcomings were the inability to keep secrets and the habit of publicly asking tactless questions? Amory Ames and her husband Milo begin an investigation. All the guests who attended the masquerade on the evening of the murder are under suspicion...