Considerada una de las obras maestras del cine de terror y ganadora del Oscar al mejor guion adaptado, El exorcista, dirigida por William Friedkin en 1973, está basada en la novela homónima de Willam Peter Blatty, inspirada en un hecho real ocurrido en la década de los cuarenta.
Una niña de apenas once años sufre terribles transformaciones, sobre todo en su comportamiento. Ni médicos ni científicos ni psicólogos son capaces de hallar la causa, pero todo parece indicar que está poseída por un demonio; será el sacerdote Karras quien se enfrentará a esta temible fuerza del mal.
William Peter Blatty was an American writer and filmmaker. He wrote the novel The Exorcist (1971) and the subsequent screenplay version for which he won an Academy Award. Born and raised in New York City, Blatty received his bachelor's degree in English from the Georgetown University in 1950, and his master's degree in English literature from the George Washington University in 1954. He also wrote and directed the sequel "The Exorcist III". Some of his other notable works are the novels Elsewhere (2009), Dimiter (2010) and Crazy (2010). Sourced from Wikipedia