- Directors: William Friedkin
- Producers: William Peter Blatty, Noel Marshall
- Writers: William Peter Blatty
- Genres: Drama, Horror, Thriller
- Actors: Ellen Burstyn, Linda Blair, Max von Sydow, Jason Miller, and, Mercedes McCambridge
Based on the 1971 novel by William Peter Blatty, The Exorcist marries three different scenarios into one plot.
The movie opens with Father Lankester Merrin (Max von Sydow) on an archaeological dig near Nineveh. He is then brought to a nearby hole where a small stone head is found, resembling a grimacing, animal-like creature. After talking to one of his supervisors, he then travels to a spot where a strange statue stands, specifically Pazuzu, with a head similar to the one he found earlier. He sees both an ominous figure and two dogs fight loudly nearby, setting the tone for the rest of the film.
Meanwhile, Father Damien Karras (Jason Miller), a young priest at Georgetown University, begins to doubt his faith while dealing with his mother’s terminal sickness.
In the central storyline, Chris MacNeil (Ellen Burstyn), an actress filming in Georgetown, notices dramatic and dangerous changes in the behavior and physical make-up of her twelve year-old daughter Regan MacNeil (Linda Blair). Regan exhibits strange, unnatural powers, including levitation and great strength, and often expresses vulgar language and blasphemy in a demonic male voice during these periods. At first, Chris believes that Regan’s rapid mental and physical changes are products of the trauma of Chris’s recent divorce. Regan is forced to endure a series of unpleasant medical tests as doctors try to find an explanation for her bizarre changes. When X-Rays show nothing out of the ordinary, doctors retire the belief that Regan has brain abnormalities causing her bizarre behavior. Chris is advised by a doctor that Regan should see a psychiatrist. After Regan assaults the psychiatrist, supernatural occurrences continue to surround her at the MacNeil’s household, including violently shaking beds, strange noises and unexplained movement. The director of the film Mrs. MacNeil is starring in is found brutally murdered after being asked to babysit for Regan.
At the climax of the exorcism, Father Merrin dies of a heart attack that was possibly brought on by Regan. Father Karras tries to give him CPR, but to no avail, and notices Regan giggling as he tries to save him. Karras becomes infuriated and grabs her, and begins to strike her, and finally challenges the demon to leave Regan and enter him. The demon does enter Damien, but the priest immediately throws himself through Regan’s bedroom window in order to stop the demon from murdering her. He falls down the steps outside where, at the bottom, a devastated Father Dyer, his best friend, administers the Last Rites as Father Karras dies. Regan is restored to her normal self, and according to Chris, does not remember any of the experience. The film ends as the MacNeil mother and daughter leave Georgetown to move on from their ordeal.