The Exorcist III

A woman crawls by unnoticed - on the ceiling like a fly. A long-dead killer claims victim after victim. Flames erupt, snakes slither, the ground opens and reveals a writhing pit of the damned. The evil is back.
Also back is the creative force whose novel and screenplay shaped the trailblazing the Exorcist. Adapting his novel "Legion," William Peter Blatty writes and directs The Exorcist III, a jolting foray into terror that begins where the first film ended. George C. Scott plays police Lt. Kinderman, investigating mysterious murders. Kinderman doesn't believe in demons and possession. Not yet. (official distributor synopsis)