Alyssa is a successful businesswoman who moves into a swanky apartment complex in order to take her mind off a breakup. However, things take a sinister turn when she realizes that Robert, her landlord, has installed hidden cameras all over the apartment and is watching her every move. Robert is a lonely and troubled man who lost his daughter in a custody battle and feels unable to connect with anyone else. He becomes obsessed with Alyssa and starts to manipulate her life in increasingly disturbing ways. Alyssa starts to suspect that she is being watched and begins to unravel Robert's dark secret. In a thrilling climax, Alyssa discovers the truth about Robert's past and must fight to survive his twisted plan to replace his daughter with her.