a friend of Blatty's on whom he had based the Chris McNeil character in the novel, to the point of using some things she had said in the past as dialogue, had been interested. But Blatty refused to back down on producing, so they moved on to other projects. Paul Monash, producer of Butch Cassidy and the Sundance Kid, then expressed interest. He and Blatty reached a $400,000 ($ in modern dollars) deal that gave Monash six months to get a studio to commit to filming The Exorcist. He soon secured a deal with Warner Bros. for $641,000. Blatty recalled that studio head John Calley had been reading the book at his home, alone, in his bedroom, and found his dog unusually unwilling to join him on the bed. He tried to drag the dog onto the bed but the animal resisted vigorously. When he finally succeeded, he found the book was hot to the touch. Blatty and Monash had agreed to be co-producers. But Monash wanted changes to the story Blatty opposed, such as setting it somewhere else, making Kinderman less colorful and Chris something other than a film actress, getting rid of the prologue and even Father Merrin's character. Hearing rumors that Monash was planning something behind his back, Blatty was able to sneak into his office at Warners and surreptitiously copy some papers from Monash's files that lent credence to those rumors. When he shared those papers with the studio, he became the film's sole producer. Writing Blatty's screenplay follows the plot of his novel closely, but narrows the story's focus. Subplots like the desecration of the churches (and the relationship between Karras and Kinderman that develops from the latter's investigation), Karras's efforts to get the Church bureaucracy to approve the exorcism, and the ongoing medical investigations of Regan's condition, are acknowledged in the film but to a much lesser degree than they are in the novel. Similarly, characters such as Chris's household staff, Dennings, and Regan's father, play a much smaller role, and the overall time frame of the plot is condensed. "I compressed the first third of my book into only 33 pages" of script, Blatty wrote later. He eliminated the subplot with Karl's daughter Elvira, despite its reinforcement of Merrin's belief that some good will always eventually come of any evil since at the end of the novel she goes into treatment for her