Hercule Poirot receives a desperate plea for help from a French multimillionaire and sets off on a journey with Hastings. When the two arrive in France, the wealthy Monsieur Renauld is already lying in his freshly dug grave - right in the middle of the golf course. The letter opener in his back belongs to his wife, leading the police to consider the case solved. However, Hercule Poirot knows that the search for the murderer has only just begun.