Lt. Bill Kinderman (George C. Scott) is investigating a series of gruesome murders occuring in the Georgetown area by a murderer who calls himself the 'Gemini killer'(Brad Dourif).  The only problem is the Gemini killer was executed fifteen years earlier, at the exact same moment Fr. Damian Karras threw himself out a window and down a flight of stairs after successfully commanding demons to possess him instead of twelve year old Regan (Linda Blair).  However, much to Kinderman's horror, the soul of the Gemini killer took possession of Karras's body as Karras lay dying.  Due to the extreme physical damage of Karras's body, the Gemini killer had to wait fifteen years for the body to heal enough for the Gemini to resume his killing.  Kinderman must quickly think of a way to stop the monster inside the body of his dear friend.

The movie was written and directed by William Peter Blatty and is based on his novel, entitled Legion.  He is also the author and screenplay writer of The Exorcist.

The Exorcist III is a decent movie with an interesting story line.  It's not nearly as good as the original, but it is better than the second one.  George C. Scott certainly adds credibility to an otherwise so-so movie.  As is usually the case, the book is better than the movie.  However, the movie is well worth the four dollars I spent purchasing it.