High school students throw a Halloween party in a mansion haunted by a young demon.

A madman who believes he's a doctor comes to the town where his crazy father was killed, and soon begins murdering people and becoming infatuated with a teenage girl who has a heart condition.

Aliens punish one of their own by sending him to earth. The alien is very violent, and when the body he occupies is damaged, he is forced to find another.

The demonic forces in the Amityville house transfer to an ancient lamp, which finds its way to a remote California mansion where the evil manipulates a little girl by manifesting itself in the form of her dead father.