MAX VON SYDOW AND JASON MILLER: (As Father Merrin and Father Karras) The power of Christ compels you. Blatty was a producer on the film, which became a cultural landmark.

1 best-seller on The New York Times list and stayed there for 55 weeks. It wasn't until a few weeks later when a guest canceled on 'The Dick Cavett Show' that Blatty was scheduled in as a last-minute replacement and spent 40 minutes recounting the story of his book that suddenly 'The Exorcist' became a No. Blatty was terrified of screwing this up, and so he spent 10 sweaty, panicky months jacked up on amphetamines so he had to sleep less writing 'The Exorcist.' The book went to the publisher. The book was called 'The Exorcist.' The editor bought it on the spot. And one night at a New Year's Eve party in 1969, he pitched it to an editor from Bantam. HENDRIX: But there was a book that Blatty wanted to write badly. Everything I do is carefully planned, madame. PETER SELLERS: (As Jacques Clouseau) I know I fell off the sofa, madame. TRACY REED: (As Dominique Ballon) You fell off the sofa, you stupid. (SOUNDBITE OF FILM, 'A SHOT IN THE DARK') And those Jesuit priests are the ones who made that first impact on him and opened his eyes to this bigger world, and set him on a path that took him to Hollywood, where he mostly wrote Blake Edwards comedies like 'What Did You Do In The War Daddy?' and the second 'Pink Panther' film.

HENDRIX: Lebanese-American, raised by a single mother who sold jelly on the streets to put her children through school, Blatty grew up in absolute poverty. MERCEDES MCCAMBRIDGE: (As Demon) Shove it up your you. MAX VON SYDOW: (As Father Merrin) I cast you out, unclean spirit. And he spent the rest of his life trying to prove the existence of God. A world where evil ruled was not the world he saw around him. GRADY HENDRIX: If you remember Roman Polanski's 1968 film, it ends with Mia Farrow giving birth to Satan's child. Hendrix says that side was fired up after seeing another horror classic, 'Rosemary's Baby.' Grady Hendrix is an author and pulp horror fan, and he says most people will associate Blatty with demons and projectile vomiting, but there was a second, more theological side to William Peter Blatty. He terrified readers in 1971 with 'The Exorcist,' and two years later the movie version shocked and disturbed, well, pretty much everyone else. One of them was author and filmmaker William Peter Blatty. During this final week of 2017, we're remembering a few notable people who died this year.

The exorcist blatty