While serving his country in the Great War, C. S. Lewis’ the great British writer, scholar, lay theologian, broadcaster, and Christian apologist–made a pact with a close friend and fellow soldier. If one of them died, the survivor would take care of his family–a promise Lewis honored. Developing a deep friendship with his fallen friend’s mother, Jane King Moore, Lewis moved into the Moore household after the war. Returning to Oxford, the twenty-three-year old Lewis–then a staunch atheist–struggled to adapt to life in post-war England. Eager to help the tormented young man, Jane encouraged him keep a diary of his day-to-day life. Those reflections are collected in this illuminating journal.