When her father seemingly goes missing, divorcee Laura LeCrois is forced to return home after a 20-year hiatus. However, home is not the way Laura remembers it. Her father is in major debt with the bank, her ex-boyfriend is the town sheriff, and her ex-husband has quit his job as a world-renowned professor who is now suspiciously buying up swampland in the area. In an effort to save the swamp and to pass the time, Laura decides to work the dying family business giving boat tours of the Louisiana swamp. But on her first sunset tour, deep in the swamp, Laura and her passengers witness two Bayou swamp rats toss a squirming body into a gator pit, only the gators aren't the ones that feast on the flesh. Instead it's the most terrifying creature Laura has ever seen...

在南极大陆上矗立着一座由各国政府合建，无人能脱逃戒备最森严的监狱，专门监禁来自全球最危险的犯人，而少数知道这座监狱存在的人则称之为“新恶魔岛”；当狱中的犯人意外从南极冰原挖出一只被冰冻的巨型史前蜥蜴（恐龙）时，曾当过考古学家的政治犯尤里告知典狱长（克瑞格华森）这是项空前的考古学突破，典狱长因而打破安全规定向外界告知这项发现。尤里的旧识，考古学博士罗勃（狄恩肯）因而搭机前往南极冰原察看这只前所未见的稀有恐龙，然而在博士抵达前，这只蜥蜴竟从五千万年的冬眠中苏醒，并在监狱中大开杀戒；在这座号称固若金汤的监狱中，无法脱逃的犯人和狱卒成了这只史前生物的大餐，他们能完成不可能的任务，找到逃出这座监狱的方法吗？