Based on actual accounts of werewolf sightings in Walworth County, Wisconsin, the film follows a local sheriff who is finally forced to accept that a string of horrifying deaths is linked to a predator which possesses DNA of both man and wolf.

When Special Agent Watts and his Investigation Unit are called to the derelict Woodburrow Prison he thinks it's business as usual. But there's nothing usual about Woodburrow. A mysterious woman is found attempting to flee the scene and things begin to spiral out of control as an evil force picks the team off one by one. Soon Agent Watts is left alone to face what might be the world's most powerful evil... The Devil.

影片讲述日籍空手道教练收了一个女徒弟，她是他的战友的孙女。她倍受同学欺负，因而要拜宫木为师，学空手道自卫，最后成为空手道比赛的冠军。

犯人和狱警都被困在一个最大的安全监狱里，当他们被一种以人肉为食的恶魔般的野兽所捕食。当生物的力量在每一次杀戮中繁殖时，它们生存的唯一机会就是揭开拥有变形者力量的古老奥秘。