The Duke of Denver, a brother of an eccentric sleuth Lord Peter Wimsey, has taken a shooting lodge at Riddlesdale in Yorkshire. One night at 3 am, Captain Denis Cathcart, the fiancé of Wimsey's sister Lady Mary, is found shot dead just outside the conservatory. Mary finds Denver kneeling over Cathcart's body and the suspicion falls on him. After it is found that Denver was seen arguing with Cathcart earlier and that the lethal bullet had come from his revolver, the case seems to be clear. Lord Peter Wimsey arrives to investigate, along with his friend Inspector Charles Parker and they discover some interesting clues which lead Wimsey all the way to New York in order to solve this mystery.