Which C.S. Lewis book is framed as letters from the demon Screwtape to his nephew Wormwood?

The Screwtape Letters is framed as correspondence from the senior demon Screwtape to his nephew Wormwood. C.S. Lewis published the book in 1942, presenting temptation from the viewpoint of Hell’s bureaucracy.

Each letter offers advice about distracting a human “patient” from faith and virtue. The satirical perspective allows Lewis to discuss pride, anger, social pressure, prayer, and ordinary habits without presenting the advice as a trustworthy moral guide.

The book began as a series of pieces connected with wartime broadcasting and was later published in book form. Lewis dedicated it to J.R.R. Tolkien, though Tolkien disliked the work’s format and did not consider it one of Lewis’s strongest books. The letters remain among Lewis’s most frequently read works.