Stooge, Helen, and Roger are driving to a party thrown by outcast Angela Franklin and her friend, Suzanne, at Hull House, an abandoned local mortuary. The car passes by an elderly man who is carrying apples and razor blades.
Judy and her boyfriend, Jay, pick up their friends, Max and Frannie, for the party. Sal Romero, another teen, also comes and crashes the party. The house is rumored to be cursed with evil spirits. When Angela holds a sÃ©ance as a party game, Helen sees a demon's face in the mirror, which causes the mirror to shatter. This prompts a demon to come out of the crematorium furnace and possess Suzanne.
The possessed Suzanne kisses Angela, passing the demon to her. Moments later, Judy discovers that Jay only invited her to the party to have sex with her. She refuses him and is abandoned by him. Roger and Helen are unable to find an exit. Helen mysteriously disappears, forcing Roger to lock himself in Angela's car. Roger runs back in the house after Helen's dead body lands on top of the car. Stooge wanders off to find a bathroom with Suzanne and is irritated when she locks him out. Inside the bathroom, Suzanne ages and disappears into a mirror. Confused, Stooge goes to find Angela seductively dancing in front of the fireplace, which Sal finds to be too weird and leaves. Stooge is then turned on by her and begins to make out with Angela. She then rips his tongue out, he then is now possessed by demons. The party goers are then picked off one by one by the increasing number of demon possessed people. Max and Frannie are killed by a now-possessed Stooge. Jay wanders off from leaving Judy alone after finding he won't be having sex with her; Finds Suzanne in another room with her breasts out and lipstick all over her face and nipple. He then makes an advance on her; while having sex she exposes her self as a demon and gouges his eyes out, killing him.
Roger, Sal and Judy attempt to escape the demons after being chased by them throughout the house. When Judy is climbing down the roof, Angela tries to get her, but Sal struggles with her and both fall. Sal is killed after landing on a spike. Judy and Roger end up in the mortuary's crematorium, where they discover that the demons will go back to Hell when the night is over and then use fire to keep the demons at bay. The two attempt to escape and are instead chased by various demons throughout the house again. They manage to make it out of the house and climb the wall using the barbed wire. Judy is almost caught by the demons, but is then saved by Roger just in time to see the sun rise and banish the demons back to Hell.
Roger and Judy slowly walk home in a state of shock, passing by the elderly man from the first scene. The elderly man goes into his house and begins to eat one of his wife's homemade apple pies that she made with the apples into which he had stuck razor blades. The razor blades cut through his throat as they kill him. The woman kisses his head and says, "Happy Halloween dear."
Who is possessed first?
Suzanne