On a class excursion to a cave with stone age paintings the clumsy Rex gets lost. A mysterious crystal opens a gateway in time and sets him back to the stone ages, where he meets a group of prehistoric fellows and the gorgeous Eba. While teaching her English and doing some pseudo-research on her fellows, his main goal is to get her sleeping with him. However the curiosity of the clan chief disturbs his attempts.
When the door of freedom cracks open for inmate Maggie Blair at her brother's funeral, nothing stands in her way, kicking off her furious determination to unearth the gang that murdered her brother.
During the winter season, a family camping in the woods, and a group of camp counselors training in the same forest both find themselves being killed one by one by an unhinged psycho.