Under pressure from his fraternity buddies, Derek Cowley steals the keys to his abusive stepfather's secret cabin for a weekend of girls and booze. Sneaking outside for some 'private' fun, two of the guests are violently attacked by an unseen creature. The rest of the group must listen in fear as the beast hammers at the cabin door taunting them. In minutes, the cabin resembles a slaughterhouse from which Derek and his girlfriend Sam struggle to escape. Back home, Derek begins to suspect that his stepfather is the beast. Only now is the true extent of the horror unleashed.