William Peter Blatty (January 7, 1928 – January 12, 2017) was an American writer and filmmaker best known for his 1971 novel The Exorcist and for the Academy Award-winning screenplay of its film adaptation. He also wrote and directed the sequel The Exorcist III. After the success of The Exorcist, Blatty reworked Twinkle, Twinkle, "Killer" Kane! (1960) into a new novel titled The Ninth Configuration, published in 1978. Two years later, Blatty adapted the novel into a film of the same title and won Best Screenplay at the 38th Golden Globe Awards. Some of his other notable works are the novels Elsewhere (2009), Dimiter (2010) and Crazy (2010).

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