約翰原本要在周末向女友瑟琳娜求婚,但是瑟琳娜要帶一群學生進行校外攝影寫真之旅,約翰只好跟著他們一起來到美麗的寶藍湖。然而這裡的居民一點也不美麗,這裡多年前是一個挖礦的小鎮,隨著鈾汙染了水源,這裡的居民開始產生突變,加上近親繁殖,遂成為一個食人部落。瑟琳娜的學生一個接著一個受害,男的成為食物,女的慘遭輪姦,美國海軍海豹部隊退役的約翰,要如何救出他的未婚妻呢?The film follows John Crenshaw as he accompanies his girlfriend and her students on a weekend nature-photography expedition deep into the woods. What should be an educational and fun-filled weekend turns into horror as the group is besieged by an unspeakable evil - a horde of hideously disfigured, mutated humans with an insatiable taste for blood. As things go from bad to worse, Crenshaw becomes their only hope if they are going to get out alive.