Police Lieutenant McPherson investigates the brutal murder of wealthy heiress Laura Hunt, shot dead with a shotgun in her New York apartment. At first, suspicion falls on the victim's fiancé, Shelby Carpenter. However, new circumstances of the case soon become clear - and they are such that the picture of the crime changes in the most incredible way... * * *During a Christmas party in the cozy home of the spouses Charlie and Bedelia Horst, a small misunderstanding occurs - one guest was left without a gift. Charlie invites his wife to give her a ring with an artificial black pearl, which he never liked. However, Bedelia does not want to part with the ring, and then even declares that she no longer has the ring...* * *An article by a young and ambitious journalist about an old unsolved murder becomes the impetus for a whole series of new sophisticated crimes...