The first two episodes of Under the Banner of Heaven premiered on April 28. The series is an adaptation of the 2003 non-fiction book, Under the Banner of Heaven: A Story of Violent Faith, by Jon Krakauer, which examines the evolution of the Church of Jesus Christ of Latter-day Saints and the 1984 murders of Brenda and Erica Lafferty. The series based on the book will star Andrew Garfield, Daisy Edgar-Jones, Sam Worthington, Wyatt Russell, Billy Howle, Rory Culkin, and Gil Birmingham.

RELATED: Pulp Fiction Co-Stars Uma Thurman And Samuel L. Jackson Reuniting For The Kill Room

Garfield will lead the series as Detective Jeb Pyre, who investigates the murders of Brenda (Edgar-Jones) and Erica. Pyre uncovers a potential connection between the murders and the LDS Church, forcing him to evaluate his own relationship with his faith. The story will follow the events of the 1984 murder case Utah v. Lafferty, which ended with the convictions of Ron (played by Garfield’s Hacksaw Ridge costar Sam Worthington) and Dan Lafferty (Wyatt Russell), who murdered the wife and daughter of their youngest brother Allen (Outlaw King’s Billy Howle).

Prior to the murders, the Laffertys had been excommunicated from the LDS Church for their extremist views, which included polygamy. After their excommunication, the Laffertys formed a group called the School of the Prophets. The brothers considered themselves prophets and claimed that they would receive orders from God and act according to his revelations. Alongside from their relationship with the church, their views also caused tension in the family. Their youngest brother Allen was barred by his wife, Brenda, from joining the School of the Prophets. The School’s extremist beliefs would drive Ron’s wife to divorce him in early 1984.

Ron blamed a handful of people for his divorce. The list included Chloe Low, the former LDS Relief Society president, who supported Ron’s wife’s decision to leave him; and Highland LDS Stake President Richard Stowe, who helped excommunicate him from the church. The other names on Ron’s list were Brenda and Erica. Ron would soon claim to receive a revelation from God that sentenced Low, Stowe, Brenda, and Erica to death. It became known as “the removal revelation,” as these four were blamed for stalling the progress of God and the prophets. Ron shared the revelation with the School of the Prophets, and eventually, Ron and Dan would set out to fulfill the missions they believed had been ordained by God.

On July 24, 1984, Dan and Ron Lafferty traveled to the home of their youngest brother, his wife, and daughter. Their vehicle contained both guns and knives to carry out the revelation, but the brothers would only use the knives. Both Brenda and Erica were found with their throats cut. Brenda was beaten and strangled with the cord from a vacuum before Ron slit her throat. Dan killed Erica in her crib. At the time of their deaths, Erica was only 15 months old, and Brenda was only 24. From there, the brothers left the home with the intent of killing Low and Stowe. After discovering Low wasn’t home, the brothers missed the turn for Stowe’s home, and continued to drive.

Dan and Ron Lafferty were arrested on August 17, 1984, at the Circus Circus casino in Reno, and charged with murder. For their crimes, Dan was able to avoid the death penalty and was instead sentenced to serve two life sentences. Ron, the credited devisor of the murder plots, received the death penalty. After his sentencing, Ron would file several appeals, and the court would struggle to evaluate Ron’s competency to stand trial. In 1996, Ron was retried and once again found guilty of his crimes. However, the state of Utah would never carry out his death sentence, and Ron would die in prison in 2019. Dan continues to serve his sentence in a maximum-security prison.

Krakauer lifted the title of his book from an 1880 address from former LDS Church President John Taylor. In it, Taylor advocated for man to take more than one wife and stated that “God is greater than the United States.” Taylor argued that when the government opposes heaven, that believers “will be ranged under the banner of heaven” against the U.S. government.

Molding Krakauer’s novel and facets of the case into a limited series is no easy feat. The use of Detective Pyre and his discoveries around the case will appear just as devastating and blood-curdling as many of the small-town citizens first found it in 1984. The real-life basis for the story only adds to its skin-crawling nature, and the series is not for the faint of heart.

The first two episodes of Under the Banner of Heaven premiere on April 28, 2022, on FX on Hulu.

MORE: This 2000s Thriller totally Embraces Its Wild Plot Twist