约翰上尉(盖·皮尔斯 Guy Pearce 饰)因表现懦弱而被军方调派到荒芜的内华达山脉前哨基地驻守,与一群劣等士兵过着无聊乏味的生活。这里偏远荒凉,孤立无援。突然,一个名叫艾维斯(罗伯特·卡莱尔 Robert Carlyle 饰)的苏格兰男子闯入了军营,并向鲍尔上尉述说了一个令人不寒而栗的故事。他曾与一队人前往此地,在途中遭遇了大风雪,被迫躲进山洞避寒。然而,由于饥饿和绝境的压力,这些人竟然开始相互残杀并食人肉以求生存,只有艾维斯最终逃出了这场疯狂的山洞事件。 鲍尔上尉听闻后带领部队前往山洞调查,但他们发现了一个令人震惊的秘密:艾维斯并非普通人,而是一个食人魔。这个发现让他们陷入了更大的恐慌和危险之中,不仅是面对自然环境的挑战,还要对抗一种不同寻常的恐怖存在。Captain John Boyd receives a promotion after defeating the enemy command in a battle of the Mexican-American War, but because the general realizes it was an act of cowardice that got him there, he is given a backhanded promotion to Fort Spencer, where he is third in command. The others at the fort are two Indians, George and his sister, Martha, who came with the place, Chaplain Toffler, Reich, the soldier; Cleaves, a drugged-up cook; and Knox, who is frequently drunk. When a Scottish stranger named Colquhoun appears and recovers from frostbite almost instantly after being bathed, he tells a story about his party leader, Ives, eating members of the party to survive. As part of their duty, they must go up to the cave where this occurred to see if any have survived. Only Martha, Knox, and Cleaves stay behind. George warns that since Colquhoun admits to eating human flesh, he must be a Windigo, a ravenous cannibalistic creature.