Cabin In The Woods

You successfully kill the creature by hitting it in the heart with the axe.. as it may be a creature that can only die from a stab to the heart. You look over and see your friend is gone, you go running upstairs and see her standing at the end of the hall, only she looks odd. You call out her name, "Amy?". No answer. "Amy why are you acting strange, come over here.". Still no answer. Just her stale cold body standing there in silence. You go a little closer and as she slightly turns around you begin to realize, that is no longer Amy..