Hercule Poirot, the little Belgian detective has returned to Styles Court, the scene of his first English adventure in crime for his final case. But now the handsome country mansion is a guest house and Poirot, old and arthritic, is one of the guests. He invites Captain Hastings to join him and then reveals the reason for his request. Poirot informs his old friend that they are "here to hunt down a murderer." And to find out who is the killer, first a murder has to be committed. But who will be the victim?