In 1974, at the Glensville Sanatorium in West Virginia, three deformed patients known as the Hillicker Brothers escape from their cells and release the other patients; together they massacre the orderlies and doctors.
Twenty-nine years later, in 2003, nine Weston University students: Kenia (Jennifer Pudavick), Jenna (Terra Vnesa), Vincent (Sean Skene), Sara (Tenika Davis), Bridget (Kaitlyn Leeb), Kyle (Victor Zinck, Jr.), Claire (Samantha Kendrick), Daniel (Dean Armstrong) and Lauren (Ali Tataryn) – are snowmobiling on their way to their friend Porter’s cabin in the mountains. However, they get lost in a snowstorm and are forced to take shelter in the Glensville Sanatorium for the night, where the Hillickers are living. Lauren remembers her brother’s stories about the sanatorium and the cannibalistic Hillickers, but her friends don’t believe her. As the group goes to bed, Vincent continues to explore the asylum, where he finds Porter’s corpse before being killed by Saw Tooth by an iron rod through the nose.
The next day, with the storm still in full effect, the teens remain trapped and go in search of Vincent. Jenna comes across the Hillickers butchering Porter’s body in the kitchen and runs back to warn the others. After Porter’s severed head is thrown at the group, Claire is hung from a balcony with barbed wire by the trio and decapitated. The group attempts to flee the building but find their snowmobiles have been sabotaged. Lauren skis down the mountain to seek help while the others barricade themselves in a doctor’s office.