In 1973, Lankester Merrin is a veteran Catholic priest and exorcist who is shown to be on an archaeological dig in the ancient city of Hatra in Iraq. There he finds an amulet that resembles the statue of Pazuzu, a demon of ancient origins with whose history Merrin is familiar.
In modern-day Georgetown, actress Chris MacNeil is living on location with her 12-year-old daughter Regan, where Chris has just wrapped the final scene of a film about student activism directed by her friend and associate Burke Dennings. After playing with a Ouija board and contacting a supposedly imaginary friend whom she calls Captain Howdy, Regan begins acting strangely, including making mysterious noises, stealing, constantly using obscene language, and exhibiting abnormal strength. Chris hosts a party, only for Regan to come downstairs unannounced, telling one of the guests, who is an astronaut, “You’re gonna die up there”, and then urinating on the floor. Later, Regan’s bed begins to shake violently, adding further to her mother’s horror. Chris consults a number of physicians, but Dr. Klein and his associates find nothing physiologically wrong with her daughter, despite Regan undergoing a battery of diagnostic tests.
Starring: Ellen Burstyn, Max von Sydow, Lee J. Cobb, Kitty Winn, Jack MacGowran, Jason Miller, Linda Blair,