His books have sold millions, including classics like Mere Christianity, The Screwtape Letters and The Lion, the Witch and the Wardrobe. Yet C. S. Lewis was not always a literary giant of Christian faith. How did he leave behind a staunch atheism to become one of the most beloved and renowned Christian authors of our time? Other biographies of Lewis explore his childhood or his dramatic conversion to Christianity. But as David Downing reveals in this fascinating book, the rarely discussed period from Lewis's childhood to his early thirties took him on a tumultuous journey of spiritual and intellectual exploration before he became a "most reluctant convert." It was not despite this journey but precisely because of it that Lewis understood the search for life's ultimate meaning so well and went on to become one of the most compelling authors of the twentieth century. Weaving the people, places and events of Lewis's life together with excerpts from Lewis's own writing, Downing shows how Lewis's spiritual quest can also light the path for other seekers.