By all accounts, sweet-faced Regan McNeil (Blair) is a normal, healthy young girl.

But when she begins exhibiting strange and violent behavior, her alarmed mother (Burstyn) doesn't know where to turn for support...

Who could be responsible for the torment (& danger) her daughter now endures?

Could it be, the once-faithless must now have faith in order to battle the diabolical onslaught they face?

Friedkin's churning terror is both provocative and evocative. It stimulates the viewer's feelings both about faith and human nature, and then draws them forth as a shield (or explanation?) for the raw, extreme events that are showcased.

The entire cast is terrific, not surprisingly Blair, Burstyn and von Sydow especially.

A modern classic - and the progenitor of countless demon/possession ripoffs throughout the rest of the decade.

The powerful theme Tubular Bells is quite capable of permanently searing itself into your psyche.