As author of the revered Narnia chronicles, C.S. Lewis is a literary legend. But the story of how this one-time atheist became an influential voice in modern Christianity is as fascinating as his fantasy world of lions, witches and wardrobes. Initially seen as a failure by friend J.R.R. Tolkien, Lewis's Narnia novels went on to sell millions of copies. This documentary traces the author's spiritual journey and the literary legacy he left behind.

• Documentary