Growing up in a conservative polygamous community, Eliza Christianson was a young woman of faith who could never quite wrap her mind around the fundamentalist aspects of her religion. Thanks to her older brother Jacob, she managed to survive adolescence unmarried, even enrolling in classes at the University of Utah. Eliza always suspected God had more in store for her than just to be some man's third or fourth wife; nonetheless, she is surprised when Allison Caliari seeks her out for help. Allison's daughter Madeline has been recruited by a doomsday cult led by a cruel man known only as the Disciple, and she wants Eliza's help to get the girl back. One of the few leads Allison can offer is a fateful one: Jacob and Eliza's brother David, a "lost boy" shunned by the church. Eliza sets out to convince David to help her infiltrate the cult, and she ventures to an abandoned dumping ground in the Las Vegas desert to rescue Madeline.