The show, adapted from a book of the same name by Jon Krakauer, tells a series of events that lead to the murder of Brenda Wright Lafferty (Daisy Edgar-Jones) and her baby daughter on the outskirts of Salt Lake Valley, Utah, in 1984. When Detective Jeb Pyre (Andrew Garfield) investigates the internal affairs of Lafferty's family, he reveals some unknown secrets: the origin of the Church of Jesus Christ of latter-day Saints (also known as Mormonism) and the violent consequences of firm faith. As a devout Mormon, Pyre discovered something that made him question his beliefs.