"When I close my eyes to sleep at night, I can feel the devil watching me." Paranoid from experience and haunted by grief, a widowed mother devotes her life to protecting the one person she has left in the world: her young daughter, Emma. But something is trying to worm its way into their lives. Something that lives in the attic - and desperately wants out. It pretends like it's her daughter, too. At times, it's almost convincing. If she ever fails to see through the mask of innocence it wears, there will be hell to pay.