Hercule Poirot receives an urgent summons from a South American millionaire living in France. When Poirot arrives, the millionaire has been found stabbed to death.
When her husband is found murdered, all eyes turn to Jane Wilkinson, especially since she was seen entering his study only moments before the body was found.
When an emaciated stranger covered in mud stumbles into Hercule Poirot's apartment, shouting half-crazed warnings about the "Big Four" and dies, Hercule finds himself involved in a bizarre mystery.
Belgian detective Hercule Poirot, now aged and crippled, calls upon his old friend Captain Hastings to help him stop a murderer who is operating out of Styles Court, the scene of Poirot's first case.
Hercule Poirot investigates the double suicide deaths of Lord and Lady Ravenscroft that occurred twelve years ago. There are hints that it was not suicide after all.