In a remote, snowbound wilderness, three desperate convicts blast their way out of a maximum security prison on Christmas Eve. At the same time, Robin and Monica leave a party given by Robin's father John Adams. Driving slowly on the ice-slicked country roads, they are captured by the escapees. Randy, the young getaway driver forced into the escape by the evil Face and powerful Mungo, avoids a police roadblock by turning into the site of the long-closed "Forever Mine." Their vehicle crashes through the rotting cover over an old mine shaft, killing Mungo. The surviving four are left to seek a way out of the maze of old tunnels. They soon learn that something terrible lives in the mine.