Patrick O'Leary, a trusted parish benefactor, was winning Mrs. McCarthy's favor until his just-fired gardener Angelica Evans dies of cyanide poisoning while standing up in mass to reveal his dark secrets and father Brown discovers he's a bigamist secret, whose "O'Leary's house of God" included his ex Angelica, his widowed niece Maria Hardy, his docile housekeeper Francesca and her teen son George Chase. Mrs McCarthy's last date with Patrick provides Father Brown a clue to solve the murder while Inspector Mallory and mislead others act on dangerous wrong presumptions.
—KGF Vissers