 In New York City, Dahlia (Jennifer Connelly) has just divorced from her husband and is disputing the custody of their daughter Cecilia (Ariel Gade). She has a very restricted budget, so she moves with Cecilia to an old small apartment in an island near Manhattan. She does not pay attention to a stain of water on the ceiling of the bedroom, but once living in the place, she realizes that there is a drip of dark water in the bedroom and she asks the landlord to repair the leakage. Meanwhile, Cecilia finds a red Hello Kitty bag on the terrace, and Dahlia returns it to the administrator. In school, the teacher tells Dahlia that Cecilia has an imaginary friend called Natasha. Along the days, Dahlia has severe migraines and nightmares, while disputing her daughter in the justice and having troubles in the apartment. Dahlia decides to investigate further, and she faces a tragic accident.