当已离婚的罗拉知道父亲失踪后，她便再次重返二十年没有回过的家，但可惜家乡已不再是她回忆中的那样。罗拉仍然决定接手快将没落的家族生意，就是带旅客到路易斯安那沼泽参观。这一天，当她带着旅客进入沼泽时，一条庞大的黑影，已悄悄在他们身边徘徊，究竟是谁令这史前巨物重生，还是，它们根本从来没有灭绝过？罗拉跟她的旅客们是否能逃出生天？

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...a cloned Pliosaur dinosaur, affectionately known as Predator X. An early ancestor of the alligator and called the "T-Rex of the ocean", Predator X is nearly 50 ft long, has giant, razor sharp teeth and is lightning fast in the water. Now, lost in the Louisiana wetlands, Laura must save her tour from a prehistoric predator that is supposed to be extinct!