Synopsis: Casey and her fellow Rockton sheriff's deputy Will chase a cabin-fevered resident into the woods, where they are stranded in a blizzard. Taking shelter in a cave, they discover a former resident who's been held captive for over a year. When the bodies of two other women turn up, Casey and her colleagues must find out if it's an outsider behind the killings or if the answer is more complicated than that... before another victim goes missing.