The original trilogy revolves around the members of the Freeling family, who are stalked and terrorized by a group of ghosts, led by a demon known as the Beast, that are attracted to the youngest daughter, Carol Anne.

The story focuses on the Freeling family, which consists of parents Steve (Craig T. Nelson) and Diane (JoBeth Williams); teenage daughter Dana (Dominique Dunne); eight-year-old Robbie (Oliver Robins); and five-year-old Carol Anne (Heather O'Rourke), who live in Cuesta Verde, a California housing development which comes to be haunted by ghosts.

Much of the film involves the family's efforts to rescue their daughter, aided by a group of parapsychologists (Beatrice Straight, Martin Casella, Richard Lawson) and spiritual medium Tangina Barrons (Zelda Rubinstein).

Carol Anne is eventually rescued from the other side and, following a second attack by the Beast that reveals the ghosts had originated from an improperly relocated cemetery beneath the neighborhood, the Freelings flee Cuesta Verde just before the house implodes and disappears into another dimension.

To protect Carol Anne, the Freelings have sent her to live temporarily in a Chicago skyscraper with skeptical relatives Pat and Bruce Gardner (Nancy Allen and Tom Skerritt) and their daughter Donna (Lara Flynn Boyle).

[21] The Curse of Poltergeist, a documentary film based on the mystery of the franchise, was set to begin shooting in November 2015, with Adam Ripp as director; financing and production was to be provided by his company Vega Baby, alongside Indonesia-based MD Pictures.

The documentary intended to focus on the life and experiences of actor Oliver Robins, who played Robbie Freeling in the first and second installments of the franchise, as a way to explore the tragedies that have befallen those involved with the films.