Follows the harrowing journey of three frontiersmen who set out to seek aid at a desolate Army fort after their handcart company becomes stranded and stricken by disease. Harassed by bandits and a mysterious native figure, with one companion gravely injured, they are stalked by a dark, primal force. As the fort reveals itself to be a cursed and maddening prison, fear and hunger twist the men into something unrecognizable—something monstrous.