What is the title of C.S. Lewis's 1942 epistolary satire about a senior demon advising a junior tempter?

C.S. Lewis's 1942 epistolary satire about a senior demon advising a junior tempter is The Screwtape Letters. The book is presented as correspondence from Screwtape to his nephew Wormwood, who is trying to influence a human subject.

Lewis uses the demonic viewpoint to examine temptation, pride, distraction, self-deception, and ordinary moral choices. The satire works by reversing the usual perspective: readers are shown human life through the strategic language of Hell, while the book's implied moral framework comes from Christian theology.

The work first appeared in serial form in the Anglican newspaper The Guardian before being published as a book. It is often confused with The Great Divorce because both are religious works using imaginative fiction, but The Screwtape Letters is specifically structured as letters from one demon to another.