Not only did William Peter Blatty write the second sequel to this film, he directed it as well
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and seen two sequels (Exorcist II: The Heretic, which Blatty was not involved in,... [DOC] [TLE] The Strange Saga of the EXORCIST Sequels [PAR] I'm not saying it's a good movie, mind you, just that it's far from the trashy low 
budget ...