When historian John Turner decided to write a book about Mormonism, it didn't take him long to settle on Brigham Young as his object of study. Turner says that the LDS Church's second leader was a colossal figure not just in American religion, but also in the history of politics and westward expansion. His new biography reveals a complicated man: blunt, aggressive and sometimes profane, but also charismatic and a fierce protector of his people. Thursday, Turner joins us to talk about the "Pioneer Prophet."