Our main heroes are as always Hercule Poirot and Arthur Hastings. The story takes place in northern France, giving Poirot a hostile competitor from the Paris Sûreté.
Paul Renauld, who has requested Poirot's help, is found dead the morning of his arrival. He is stabbed in the back with a knife and left in a newly dug grave adjacent to a local golf course. His wife, Eloise Renauld testifies that several masked men broke into the villa at 2 am, tied her up, and kidnapped her husband. Poirot notes straight away some strange facts about the case: a piece of lead piping is found near the body; only three female servants were in the villa as both Renauld's son Jack and his chauffeur had been sent away; an unknown person visited the day before.