The Exorcist is a 1973 American horror film. It was directed by William Friedkin. The movie was rated R by the Motion Picture Association of America for strong launguage and disturbing images.
At an archaeological dig in Northern Iraq, archaeologist Father Lankester Merrin visits a site where a silver Roman Catholic medallion along with a small stone amulet resembling a grimacing monster are found buried together.
Meanwhile, Father Damien Karras, a young priest at Georgetown University in Washington, DC, begins to doubt his faith while dealing with his mother's illness. A friend, Father Joe Dyer, tries to advise and console him.
While making a film near her temporary residence in Georgetown, actress Chris MacNeil notices dramatic and dangerous changes in the behavior of her 12-year-old daughter, Regan. When X-rays show nothing out of the ordinary, a doctor advises that Regan be taken to a psychiatrist, whom she assaults. Paranormal occurrences continue, including a violently shaking bed, strange noises, and unexplained movements. A film director, Burke Dennings, visiting the MacNeil home, dies violently, found at the bottom of steps that run the full length of the house, as well as onto a nearby street, where Dennings broke his neck upon landing. Lieutenant Kinderman investigates, and confides in Karras that Dennings' head was found fully twisted around his shoulders. Kinderman also speaks with Chris and promises to return when Regan is feeling better.
Just after Kinderman leaves, Chris is brutally attacked by her daughter, leaving her with facial bruises.
When all medical explanations are exhausted, doctors recommend an exorcism. In desperation, Chris consults Karras, who is both a priest and a psychiatrist. During a period in which Karras observes Regan, she constantly refers to herself as the Devil. Despite his doubts, Karras decides to request permission from the Church to conduct an exorcism. Merrin requests that he and Karras take a break, whereby he administers to himself the viaticum, a sign of his impending doom at the hands of the demon. Merrin excuses the younger priest and begins the exorcism, once more on his own.
Karras returns to find Merrin has suffered a fatal heart attack. He attempts to perform CPR to no avail, but Regan is proud of it. Karras strikes and chokes her, challenging the demon to leave Regan and enter him.
Regan is restored to health and does not appear to remember her ordeal. Chris and Regan leave Georgetown and their trauma behind. They return Karras' silver medallion to Dyer, who takes one final look down the steps behind the house and departs.