Book excerpt: In William Peter Blatty on The Exorcist: From Novel to Film, the New York Times bestselling author reveals the real-life incidents that inspired his famous novel and how it evolved into the groundbreaking Academy Award-winning screenplay of the 1973 groundbreaking William Friedkin film. Featuring the original, controversial ending of the novel, and both the first draft of the screenplay and the shooting script, Blatty presents his behind-the-scenes commentary on the differences between the book and screenplays, detailing the specific reasons why the changes were made for the final cut. This is the true story of the making of The Exorcist, an insider's guide to Hollywood in one of its most creative eras. Includes photographs At the Publisher's request, this title is being sold without Digital Rights Management Software (DRM) applied.