The Freeling family move in with Diane’s mother in an effort to escape the trauma and aftermath of Carol Anne’s abduction by the Beast. But the Beast is not to be put off so easily and appears in a ghostly apparition as the Reverend Kane, a religeous zealot responsible for the deaths of his many followers. His goal is simple – he wants the angelic Carol Anne; but the love of her family and the power of psychic Tangina once again unite, along with an elderly native American, to fight for her life. —IMDb
The scene where Kane arrives at the house in the summer rain is genuinely masterful and scary as hell. The best part of an otherwise mediocre movie (but one not entirely without its merits).
Somewhere in Poltergeist II there's this compelling story of Craig T. Nelson overcoming his alcoholism to become a spiritual warrior of the Carlos Castaneda variety. Sadly, that story has no place here.