Winter, 1864. William Singer and his young brother Henry, along with four other Confederate POWs, escape from a Union prison camp outside Chicago. They seek refuge in the storage car of a train but the next morning, they find the passengers brutally butchered by what appears to be a wild animal. It isn't long before they discover that "wild animal" is no animal at all, but a pack of Native American shape-shifting werewolves with an insatiable blood lust for human flesh. Hunted by werewolves, stuck in the freezing cold Illinois wilderness with no food, no water and nowhere to go, they discover the hell they left is nothing compared to the hell they will encounter.