When Father Brown hears in the confessional the penitent confess they are going to kill Bishop Talbot the next day during a shooting party the Bishop is attending. Unable to reveal what he has heard he goes to the shoot organized by a theatrical producer and in saving the Bishop Albert Davies the Bishops Assistant is killed; and Father Brown discovers a deadly pact involving a child abuse victim and the murdered man's wife to kill another man providing unbreakable alibis.