Season 1, Episode 9

Mayor William Knight is electrocuted by a microphone at the annual village fundraiser. Valentine arrests Knight's wife Eleanor after finding a screwdriver in her handbag, but there are plenty of other suspects, including his young daughter and the secretary he fired after their affair was discovered. As Father Brown works to solve the mystery, he discovers that a magician at the celebration is his housekeeper Mrs. McCarthy's husband, who was presumed dead.