What was the title of C.S. Lewis’s 1942 book based on correspondence between a demon and his apprentice?

The Screwtape Letters is C.S. Lewis’s 1942 book based on correspondence between a demon and his apprentice.

The work consists of letters from Screwtape, an experienced demon, to his nephew Wormwood. Screwtape offers advice on tempting a human being, allowing Lewis to present moral and theological observations through an intentionally inverted viewpoint.

Lewis wrote the letters during the Second World War, and they first appeared in the Anglican newspaper The Guardian before being collected as a book. The unusual satirical format made the work distinctive among Lewis’s Christian writings.

Mere Christianity, The Problem of Pain, and The Great Divorce are related works of Christian apologetics and imagination, but they use different structures. The Screwtape Letters is specifically defined by its fictional demonic correspondence and its epistolary form.