Peter McAuslan heeded Mormon missionaries spreading the faith in his native Scotland in the mid-1840s. The uncertainty his family faced in a rapidly industrializing economy, the political turmoil erupting across Europe, the welter of competing religions-all were signs of the imminent end of time, the missionaries warned. For those who would journey to a new Zion in the American West, opportunity and spiritual redemption awaited. When McAuslan converted in 1848, he believed he had a found a faith that would give his life meaning. A few years later, McAuslan and his family left Scotland for Utah, but soon after he arrived, his doubts grew about the religious community he had joined so wholeheartedly. Historian Polly Aird tells the story of how McAuslan first embraced, then came to question, and ultimately renounced the Mormon faith and left Utah. It would be the most courageous act of his life. In Mormon Convert, Mormon Defector, Aird tells of Scottish emigrants who endured a harrowing transatlantic and transcontinental journey to join their brethren in the valley of the Great Salt Lake. But to McAuslan and others like him, the Promised Land of Salt Lake City turned out to be quite different from what was promised: droughts and plagues of locusts destroyed crops and brought on famine, and U.S. Army troops threatened on the borders. Mormon leaders responded with fiery sermons attributing their trials to divine retribution for backsliding and sin. When the leaders countenanced violence and demanded absolute obedience, Peter McAuslan decided to abandon his adopted faith. With his family, and escorted by a U.S. Army detachment for protection, he fled to California. Mormon Convert, Mormon Defector reveals the tumultuous 1850s in Utah and the West in vivid detail. Drawing on McAuslan's writings and other archival sources, Aird offers a rare interior portrait of a man in whom religious fervor warred with indignation at absolutist religious authorities and fear for the consequences of dissension. In so doing, she brings to life a dramatic but little-known period of American history.