In UNDER THE BANNER OF HEAVEN, John Krakauer shifts his focus from extremes of physical adventure to extremes of religious belief within our own borders. At the core of his book is an appalling double murder committed by a pair of brothers, Ron and Dan Lafferty, who insist they were commanded to kill by God. Beginning with a meticulously researched account of this "divinely inspired" crime, Krakauer constructs a multi-layered, bone-chilling narrative of polygamy, savage violence, and unyielding faith. Weaving the story of the Lafferty brothers and their fanatical brethren with a clear-eyed look at Mormonism's violent past, Krakauer examines the underbelly of the United States' most successful homegrown faith, and finds a distinctly American brand of religious extremism.