Actress Chris MacNeil (Ellen Burstyn) has every reason to be content, having just completed a film with director Burke Dennings (Jack MacGowran). However, she becomes disturbed by the changes taking place in her 12-year-old daughter, Regan (Linda Blair). At first sullen and withdrawn, Regan becomes aggressive and blasphemous, and ugly welts appear on her face and body. No medical cure is forthcoming, and after Burke is killed by being thrown from Regan's window, Chris turns to local Jesuit priest Father Damien Karras (Jason Miller) for help. Karras then calls in exorcist Father Lankester Merrin (Max von Sydow), who confirms that Regan is possessed by the devil. William Peter Blatty's screenplay, based on his own novel inspired by actual events, won an Oscar, and the film was deemed so powerful that it was refused a BBFC certificate for fifteen years.