William Peter Blatty won a best screenplay Oscar for this adaptation of his bestselling novel about the demonic possession of an actress's young daughter, one of the most talked-about and reviled horror movies ever. Unbelievably scary when it first came out, its overall impact has been lessened by time and repeated genre duplication. But the macabre, obscene demonstrations of manifest evil still retain their power to startle and nauseate, particularly Linda Blair's "head-turning" antics as the possessed child. Aside from the graphic and revolutionary special effects, director William Friedkin dwells on the allegorical religious subtleties, making this a richly satisfying experience for horror aficionados. Max von Sydow (as the priest at the centre of the exorcism) and Ellen Burstyn (as the girl's mother) also rise to the landmark occasion, and special mention should go to Robert Knudson and Chris Newman, whose marvellous use of sound won the film's second Oscar.

When a mysterious entity possesses a young girl, her mother seeks the help of two Catholic priests to save her life.