A.J. Finn's The Woman In the Window tells the story of Anna Fox, an agoraphobic widow who experienced frequent hallucinations as a result of some unknown incident in her past. Anna lives in Harlem and watches her neighbors through a camera lens. Though her physicians consistently advice against it, Anna drinks several bottles of merlot each day despite being on medication for her psychological disorder. Before developing agoraphobia, Anna as a prominent child psychologist.
One day, a teenager, Ethan Russell, brings Anna a gift from his mother, Jane, when the family moves in across the street. Anna, drawing on her experience as a psychologist, believes that Ethan is afraid of his father. Anna frequently has phone conversations with her absent husband. Anna invites Ethan's mother over one evening, and the next day, Ethan's father comes over to ask if his wife visited. Afraid of the woman's vengeful husband, Anna maintains that she did not.
Anna sees Ethan's mother stabbed in her bedroom window, but when she reports it to the police, the police do not believe her. Jane Russell appears to be alive, and the police write Anna off as unreliable owing to her medication-induced hallucinations. Meanwhile, Anna receives a photograph of herself sleeping and finds her phone password changed.
Later, it is revealed that Anna's family died in a car accident after Anna left her husband for a man from her therapy practice. Anna's husband, Ed, and her daughter, Olivia, are both killed in a vehicle that Anna was driving on the way back from a ski trip. Furthermore, it turns out that Anna did in fact see a woman being stabbed, but it was Ethan's birth mother, Katie, not Jane (the woman with whom he lived). Furthermore, it turns out that Ethan was the one who sent the email with a photo of Anna, and that he has been breaking into her house to try to kill her, but himself dies in the process.