Friends Alex (Nicholas D'Agosto) and Josie (Leighton Meester) have a disturbing hobby. They like to follow strangers. One night Alex takes things too far when he sneaks into a home and gets caught...instead of calling the police, the couple, fascinated by his resemblance to their dead son Timmy, ask him to stay. As the grieving couple begins to believe that Alex really is Timmy, he finds himself trapped in a horrifying existence of desperation, despair, and insanity-and Josie, suspicious of Alex's sudden disappearance, is his only chance at escape.