Whilst surgeons are fighting to save the life of a young woman, an archaeology student found in bed with gunshot wounds to the head, Wycliffe is approached by wealthy novelist David Cleeve. He has been the regular recipient of a single playing card, the Jack of Diamonds, and on the last occasion the card was torn in half, causing Cleeve to believe that someone is out to murder him. When a man walking on a beach is indeed killed Cleeve reckons that he was the intended victim and Wycliffe uncovers a whole series of crimes starting some years earlier.