Over the course of his 60-year career, Norman Mailer has tackled some pretty controversial subjects—the life of Jesus Christ, the inner workings of the CIA, the final days of murderer Gary Gilmore—as part of an ongoing effort to understand the nature of good and evil. In his latest novel, The Castle in the Forest, he imagines the early life of the 20th century’s foremost representative of evil, Adolf Hitler, as narrated by one of Satan’s minions.