The pair pretended to be enemies, but were romantically involved. He reveals that the murder was committed by Alfred Inglethorp, with aid from his cousin Evelyn Howard. Poirot soon exonerates John of the crime.

Japp soon arrests him - the signature for the poison is in his handwriting a phial that contained the poison is found in his room a beard and a pair of pince-nez identical to Alfred's, are found within the manor. Suspicion now falls on John - he is the next to gain from Emily's will, and has no alibi for the murder. Although Japp is keen to arrest him, Poirot intervenes by proving he couldn't have purchased the poison the signature for the purchase is not in his handwriting. Poirot notes his behaviour is suspicious during the investigation - he refuses to provide an alibi, and openly denies purchasing the strychnine in the village, despite evidence to the contrary. The Cavendishes suspect him to be a fortune hunter, as he was much younger than Emily. Inspector Japp, the investigating officer, considers Alfred to be the prime suspect, as he gains the most from his wife's death. Nobody can explain how or when the poison was administered to her. Meanwhile, Emily ate little at dinner and retired early to her room, taking her document case with her when her body was found, the case had been forced open and a document removed.

Alfred left the manor early that evening, and stayed overnight in the village. She had been quite distressed after this, and apparently made a new will - no one can find any evidence that it exists. On the day of the murder, Emily had been arguing with someone, suspected to be either Alfred or John. However, the money she inherited would be distributed according to her own will, which she changed at least once per year her most recent will favours Alfred, who will inherit her fortune. Poirot learns that per Emily's will, John is the vested remainder man of the manor - he inherits the property from her, per his father's will. Her household includes: her husband Alfred Inglethorp, a younger man she recently married her stepsons (from her first husband's previous marriage) 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. Cavendish, she inherited from him both the manor and a large portion of his income. Poirot learns that Emily was a woman of wealth - upon the death of her previous husband, Mr. Mary, to enlist help from his friend staying there - Hercule Poirot. Arthur Hastings, a soldier from the Western Front staying there as a guest on his sick leave, ventures out to the nearby village of Styles St. One morning at Styles Court, an Essex country manor, its household wake to the discovery that the owner, elderly Emily Inglethorp, has died.

The mysterious affair at styles