Defying both civil authorities and the Mormon establishment in Salt Lake City, the renegade leaders of these Taliban-like theocracies are zealots who answer only to God; some 40,000 people still practice polygamy in these communities. At the core of Krakauer’s book are brothers Ron and Dan Lafferty, who insist they received a commandment from God to kill a blameless woman and her baby girl. Beginning with a meticulously researched account of this appalling double murder, Krakauer constructs a multi-layered, bone-chilling narrative of messianic delusion, polygamy, savage violence, and unyielding faith. Along the way he uncovers a shadowy offshoot of America’s fastest growing religion, and raises provocative questions about the nature of religious belief.