Everything must be taken into account. If the fact will not fit the theory-let the theory go.Emily Inglethorp, the elderly and wealthy owner of Styles Court, an Essex country manor, has been poisoned. Among the residents and guests staying at Styles are Alfred Inglethorp, a young man she recently married, her stepsons John and Lawrence Cavendish, John's wife Mary Cavendish, Cynthia Murdoch, the daughter of a deceased friend of the family, and Evelyn Howard, Emily's companion. Staying as a guest was Arthur Hastings, a soldier of The Great War on his sick leave, who travels to the nearby village of Styles St. Mary to solicit the help of his old friend, Hercule Poirot-a renowned private detective from Belgium who had been displaced to England during the war. Thus begins the chronicle of the great Hercule Poirot!