Child scientist anna Fox lives alone in Manhattan on West 121st Street once separating from her husband Edward; he lives away with their girl Olivia, however she talks to them on a usual. anna suffers from phobic disorder and her confined state leads her to look at all of her neighbors from a second-story window, together with the Russell family who recently moved in across the road. She conjointly takes an oversized range of medicines and drinks alcohol daily.
One evening, Jane Russell visits anna and that they bind each other. She conjointly meets Ethan, Jane’s immature son, who suggests his father Alistair is abusive. One night, anna witnesses Jane being injured to death within the front room. She contacts the police however they are doing not believe her, claiming everybody within the family is okay. Alistair arrives at the side of “Jane” who, to the shock of anna, may be a completely different girl from the one she met. She begins spying on the Russell family.
Anna’s tenant David, who lives in her basement, claims he didn’t hear or see something, tho’ she learns David was once in jail and stony-broke his parole conditions. She receives an anonymous e-mail with a photograph of her sleeping. She once more contacts the detectives, who area unit joined by the Russells and David in Anna’s house, and anna breaks down once it’s unconcealed by a detective that Edward and Olivia area unit dead as a results of a automotive crash that anna accidentally caused. anna is currently afraid as a result and her medication has caused her to possess hallucinations and conversations with people that aren’t there.
Anna apologizes to the Russell family and stops following her suspicions. She records a video on her telephone, reaching to kill by drug. She then discovers a photograph she took of her cat and, within the reflection of a wine glass, sees the first Jane, proving she is real. anna shows David the image and he confesses the first Jane she met may be a girl named Katie Melli, Ethan’s biological mother. Katie had been stalking the Russell family, attempting to urge on the brink of Ethan. David refuses to assist anna prove the truth; he’s then suddenly attacked and killed by Ethan, who had been lurking within the house.
Ethan reveals to anna that he dead Katie and may be a liquidator, having conjointly killed Alistair’s secretary in Bean Town, and currently intends to kill Pakistani monetary unit. He had been rental himself into her house all week with a purloined key, and he was the one who took the image of her sleeping. anna flees to the roof, wherever they fight till she pushes Ethan through the window to his death.
As anna recovers within the hospital, Detective very little visits and tells her they need inactive Alistair and Jane for serving to Ethan conceal Katie’s murder which they need found Katie’s body. very little admits he watched Anna’s suicide video, however hands back her phone to permit her to delete it before she must come back it for believing in. He apologizes for not believing her.
Nine months later, Anna, currently sober and healthy, says word of farewell to her house before she moves out and on along with her life, currently not fearful of the surface world.