Noelle and Addie have just moved into a beautiful, though impossibly cheap apartment on Manhattan's prestigious Upper East Side. Not long after their arrival, Addie's behavior drastically changes, as she begins to sleepwalk and speak in a strange child's voice, much to the horror of her boyfriend Greg. Noelle, meanwhile, becomes intrigued by a mysterious young woman who inexplicably shows up at their apartment, who reveals that she believes the apartment...