Under the Banner of Heaven: A Story of Violent Faith tells two parallel stories of murder and the creation of Mormonism. In the 1980s, Brenda Lafferty and her daughter are murdered due Brenda's in-laws' extremist beliefs in the practice of polygamy; in the 1840s, Joseph Smith founds Mormonism, and his followers (including Brigham Young) eventually end up in Utah. This nonfiction novel delves into themes of religion, polygamy, and persecution.