Attending a performance by impressionist Carlotta Adams, Hercule Poirot is approached by actress Jane Wilkinson. She requests his help in asking her husband, Lord Edgware, to divorce her. Poirot agrees but is surprised to find that Edgware has already agreed to a divorce and sent a letter to his wife confirming this; Wilkinson denies receiving it. The following morning, Inspector Japp informs Poirot and his friend Arthur Hastings that Edgware was murdered at his home in Regent Gates the previous evening, stabbed in the neck. While Wilkinson was witnessed by Edgware's butler and his secretary visiting her husband that night, a morning newspaper reveals she attended a dinner party that evening, whose guests confirm this. Poirot soon becomes concerned for Adams' safety, recalling she could impersonate Wilkinson. She is found dead that same morning from an overdose of Veronal.