It's Ed and Sarah's first night at their new home: an isolated farmhouse on the Scottish borders. This should be a new beginning away from their stressful London lives. And at first it is; come sunset they fall in love all over again on a wander in the woods. But as darkness falls, Sarah suspects they're not alone, Ed goes to investigate and quickly, the evening becomes a nightmare. It suddenly dawns on them: they do not belong here, and they certainly are not welcome.