Recently acquitted of murder, 17-year-old David has moved to Massachusetts to complete his senior year of high school. His aunt and uncle have offered him shelter—escape from the media's incessant questions and from the uncertain glances of his neighbors and ex-friends. His attic apartment doesn't feel much like a shelter, though. He sees ghostly shadows at night, his aunt is strangely cold, and his 11-year-old cousin Lily is downright hostile. And as Lily's behavior becomes more and more threatening, David can't help but wonder what ugly secrets lurk within the walls of Lily's home. There's one thing David knows with certainty. The more he learns about his cousin Lily, the harder it is to avoid thinking about his own past.