In the winter of 1974, a group of inbred cannibalistic patients riot and escape from a sanatorium in West Virginia. Decades later, a group of college friends decide to take a snowmobiling trip during their winter break. They become lost in a storm and discover the now-abandoned sanatorium, seeking shelter from the harsh weather. However, they soon realize they are not alone, encountering the terrifying descendants of the escaped patients who have been living there since the riot.

As night falls and the storm intensifies, the friends struggle to survive and find a way out of the building. Tensions rise, alliances are tested, and their numbers dwindle as the cannibals hunt them one by one. The seemingly abandoned sanatorium turns into a deadly maze, with hidden dangers lurking around every corner. Facing grotesque traps and brutal attacks, the friends fight for their lives as they seek any means of escape from the relentless killers.