This scary, riveting screenplay, by William Blatty tells the ordeal an actress, Chris MacNeil (Ellen Burstyn) and her young daughter, Regan, which begins when young Regan (Linda Blair) develops weird symptoms. Chris MacNeil comes to believe her daughter is possessed by a powerful demon. When all else fails, Chris seeks the help of a Priest, Father Damien Karr (Jason Miller), who is experienced in the ritual of exorcism, and knows well this demon as an old foe.

William Peter Blatty, who adapted his popular novel, won an Oscar for his screenplay. Blatty's novel was supposedly based on a real life incident involving a young boy.

The marvelous direction was by William Friedkin, who has had a long and lustrous career, in acting, writing and directing films such as THE FRENCH CONNECTION, THE GUARDIAN, SORCERER, RAMPAGE, RULES OF ENGAGEMENT and THE HUNTED.

Linda Blair, in her screen debut, gives a thoroughly convincing performance. Although some of her more violent scenes were actually done by an adult actress, and her "devil voice" was done by Mercedes McCambridge, young Blair does a masterful job as the afflicted girl.

Academy Award winner, Ellen Burstyn, gives a heartbreaking performance as the mother of a possessed child. We really feel her growing frustration and consternation as the conventional medical establishment offers her little help with her daughter.

Supposedly, Friedkin pulled some cinema tricks in order to make the film more shocking. Some film experts claim that frames of skulls and other items were cut into the film, at the subliminal level, to disturb the viewer. Whether this is true or not is certainly open to debate.

During the film's theatrical run, some audience members got sick, fainted, and had other adverse reactions to the film. Whether these were real reactions, or clever studio promotions, is hard to determine.

My favorite scene involves Miller and a possessed Blair. When she speaks to him with the voice of his dead mother, it's a nightmarish, truly disturbing scene.