The depletion of the earth's ozone layer causes animals above the altitude of 5000 feet to run amok, which is very unfortunate for a group of hikers who get dropped off up there by helicopter just before the quarantine is announced.
An eighteen-foot grizzly bear figures out that humans make for a tasty treat. As a park ranger tries rallying his men to bring about the bear's capture or destruction, his efforts are thwarted by the introduction of dozens of drunken hunters into the area.
Jessica Barrett, wife and mother of two young children, begins to show signs of demonic possession while pregnant with her third child. As she seeks help from her husband and doctor, a mysterious man approaches her and seems to have some answers.
Nina lives a morbid relationship with her stepfather, who is serving time in prison for the murder of the girl's mother. Nina could exonerate the man - the mother actually committed suicide because she had discovered the relationship between her daughter and her husband - but she prefers to know him in prison in order to dominate and possess him. She succeeds in guaranteeing him a regime of semi-freedom, thanks to the money she obtains by organising parties based on drugs and sexual perversion. A young American man, Matthieu, falls in love with Nina and marries her, but is soon abandoned by her when she goes to live with her stepfather, who has meanwhile come out of prison old, depressed and at the complete mercy of his stepdaughter.
The hunter becomes the prey as a Vietnam veteran (Perry King) tries to ferret out the real culprit after being tagged as the prime suspect in the murders of his former Army pals.
