What was C.S. Lewis’s wartime book about demonic temptation called?

The Screwtape Letters was C.S. Lewis’s wartime book about demonic temptation.

Published in book form in 1942, the work consists of letters from Screwtape, a senior demon, to his inexperienced nephew Wormwood. Screwtape gives advice on how to tempt a human patient away from faith, virtue, and attention to ordinary moral duties.

Lewis wrote the letters during the Second World War, and the book first appeared in the Anglican newspaper The Guardian. Its epistolary structure lets Lewis present moral observations indirectly: readers hear the demons describe methods of distraction, pride, resentment, and self-deception while understanding that their goals are corrupt.

The book is satire rather than a literal handbook of demonology. Lewis used the demonic viewpoint to expose habits that can seem ordinary or harmless. The title is sometimes shortened informally to Screwtape, but the canonical title is The Screwtape Letters.