What is the title of C.S. Lewis’s 1942 Christian apologetics book narrated by a senior demon?

The Screwtape Letters is C.S. Lewis’s 1942 Christian apologetics book narrated by a senior demon.

The work consists of letters from Screwtape, an experienced tempter, to his nephew Wormwood, who is learning how to influence a human “patient.” Lewis uses the demonic correspondence as an ironic device: advice intended to promote evil often exposes ordinary human weaknesses such as distraction, vanity, resentment, and self-deception.

The book first appeared in serial form in the Anglican newspaper The Guardian before being published as a volume. Its format makes it unusual among Lewis’s religious writings because the reader hears a case for spiritual corruption from the enemy’s perspective. Screwtape is not a sympathetic hero, and the satire is meant to reverse the reader’s assumptions. The sequel, Screwtape Proposes a Toast, appeared in 1959 and was published separately from the original letters.