In the village of King's Abbot, a widow's sudden suicide sparks rumors that she murdered her first husband, was being blackmailed, and was carrying on a secret affair with the wealthy Roger Ackroyd. The following evening, Ackroyd is murdered in his locked study--but not before receiving a letter identifying the widow's blackmailer. King's Abbot is crawling with suspects, including a nervous butler, Ackroyd's wayward stepson, and his sister-in-law, Mrs. Cecil Ackroyd, who has taken up residence in the victim's home.