Not only is "The Exorcist III" one of my favorite horror films of all time, but I also happen to think it's far better than the original film. While it's not perfect, the moments that do work are so profoundly good that it's easy to forgive all the elements the studio stupidly shoe-horned into the final cut.
The story takes place many years after father Damien Karras took that fatal tumble down that iconic stairwell following the exorcism of Regan MacNeil. Karras's old friend Detective Kinderman, played by the phenomenal George C Scott, is the central character of this sequel. The basic plot follows Kinderman as he investigates a series of familiar serial murders which suggest that the Gemini Killer is back on the streets. However, Kinderman actually made sure the creep was dead seventeen years ago. At the same time, a patient at the local sanitarium has awoken from his vegetative state with details pertaining to the killings and demands to see Kinderman. Once in Patient X's company, the detective can't help but notice that he not only resembles the original Gemini Killer, but he also at times reminds him of his friend Father Karras.
It is no great secret that it is Brad Dourif who absolutely steals the show with his intense performance as Patient X, the man at the center of all the grizzly goings on. Initially, it was solely Brad Dourif in the role, but at the oppressive whim of the studio, scenes of Jason Miller as the Patient X character were shot in order to provide a more obvious connection to the original film. Given the actual story line and Patient X's true identity, it actually wasn't a bad idea. Unfortunately, a lot of the other changes didn't exactly help the film.
Primarily, Blatty wanted to use the "Legion" title for the film. He made many attempts to keep them from using the numeral III, mainly because he wanted to distance the picture from the abominable "Exorcist II." The studio was insistent upon the use of "Exorcist" in the title, which Blatty eventually had to relent on. Unfortunately, it provided one significant problem: the movie originally contained no exorcism. So, of course, the studio blew a bunch of money on additional scenes which built up to an exorcism. Strangely, the original story has Patient X simply dying in his sleep as I recall, which would seem anti climatic. However, I think the studio's fix is way more of a let down. It's a total crown of cheese atop an otherwise dignified brow. Beyond that, if you want to be anal about the argument, the movie was titled "The Exorcist," and considering the presence of the Karras character to some extent, they actually DID have an exorcist in the film.
Despite the tampering, this movie is otherwise brimming with atmosphere, snappy dialog, electrifying performances, and also features Patrick Ewing and Fabio as angels!
A bunch of stupid assholes have forbade embedding on their "Exorcist III" trailers on youtube, though they have no formal affiliation with the production. However, I did find this excellent teaser that was never used which features an awesome logo for the movie. Thanks to DarenDoc.