The Severn family-Jeff and his wife Phyllis, Lynette and her new fianc , and single Andy-has gathered at the mountain home of their grandmother, Mary Agnes Severn, to celebrate Thanksgiving and hear an announcement regarding their late grandfather's will. With news of an escaped convict in the hills, everyone is barely settled in before a huge snowstorm strands them in the large old house with only gas lamps and lanterns to keep the darkness away...