Over a long holiday weekend, unable to escape the confines of their sorority house, a handful of unsuspecting girls are left behind to enjoy the quiet sanctuary. The normal house staff has taken off for the weekend, leaving the girls to fend for themselves. Thankfully someone was kind enough to send them a temporary replacement chef to cook their meals.

A group of attractive young people (of course) awaken to find themselves prisoners in a mysterious house with no means of escape. They are each outfitted with new accouterments–electronic devices attached to the base of their skulls–and a recording on a television screen alerts them of their task. In order to escape, they must hurt themselves and each other. The chemicals that the brain produces when in pain are collected by the devices, and when it collects a predetermined amount, the doors will be opened. Fail to do it in time, and everybody dies.

The California coast is terrorized by two enormous prehistoric sea creatures as they battle each other for supremacy of the sea.