Heather O’Rourke and Zelda Rubinstein are the only players from the first two films to cross over into the light of Poltergeist III. Here, O’Rourke’s character, Carol Anne, seemingly dumped by her parents for reasons unknown, is taken care of by her Aunt Patricia (Nancy Allen), Uncle Bruce (Tom Skerritt), and teenage step-cousin, Donna (Lara Flynn Boyle), living in a high-rise building in Chicago. Carol Anne has been enrolled in a school for gifted but troubled kids, as her therapist, Dr. Seaton (Richard Fire), thinks that the young girl has the ability to hypnotize people into believing her delusions about seeing ghosts. Seaton forces Carol Anne to speak about her experiences, which brings to light her involvement with the dreaded Reverend Kane (Nate Davis), and this talk has caused the late Reverend to cross over into trying to get in contact with the girl again. For some reason, the entire building is chock full of mirrors at every turn, which is convenient to the haunting that emerges, as most of its haunting involved scaring the bejeesus out of the family and their cohorts through reflections in whatever mirrors they happen to be looking at.
Nine months after her Oz experience, Dorothy wants to return to check in with her friends. Aunt Em thinks Dorothy is mentally ill. She seeks treatment from an experimental clinic using electroshock therapy to treat maladies of the mind. Dorothy is taken to an eerie clinic run by an uncaring Dr. Worley and the stern Nurse Wilson.
During the treatment, a mysterious girl watching over Dorothy intervenes during a lightning strike that halts the experiment. Dorothy escapes down a nearby river, washing ashore in the land of Oz again. Except the Yellow Brock Road is demolished. The Emerald City is in ruins and its inhabitants, including all of her old friends, have been turned to stone by the mad Nome King. Except for the Scarecrow, who ran Emerald City in her absence, who has been imprisoned. Along with her hen Billina, a broomstick figure with a pumpkin for a head named, obviously, Jack Pumpkinhead, a robotic soldier named Tik Tok, and a flying beast of burden named The Gump, it’s up to Dorothy to stop the mad Nome King and the evil Princess Mombi from destroying the Oz that once was for good.
Fairuza Balk stars as Dorothy in her debut feature film. Walter Murch directs and co-writes this nightmarish cult adventure.