Emily Hollander, Talia Shire, is a shy, recently divorced woman who lives alone in a Brooklyn Heights apartment. Her next-door neighbor, Andrea Glassen, Elizabeth Ashley, harbors a dangerous obsession with her that unsettles the quiet building and sets off a chain of tense events. Emily’s world feels small and fragile, and the coming storm will test her sense of safety, trust, and independence.
One night, a man forces his way into her apartment and compels her to produce sounds of erotic satisfaction, which he records on a tape recorder. The incident leaves Emily shaken, and she reports the attack to the police. While investigators speak with her, Andrea stops by to offer supposed comfort, masking a more unsettling motive behind her sympathy.
Seeking safety, Emily moves to a Manhattan apartment, hoping the distance will bring relief. But the nightmare follows: as she is in the middle of moving out, the same man makes another attempt to enter her new place. This time Andrea happens to be visiting and manages to prevent his entry, heightening the sense that nothing about the danger is accidental.
It becomes clear that Andrea is not the benevolent neighbor she appears to be. She has secretly hired a taxi driver to carry out the attacks in order to secure the recordings, which she then obsessively listens to and even recites while fantasizing about Emily. Andrea has fallen in love with Emily and envisions a twisted future where Emily will choose to live with her out of fear, security, and intimate dependence. Meanwhile, Emily continues to see Andrea as a friend, and she begins a relationship with the police detective who responded to her initial case, Detective Swid. The situation grows more perilous as Andrea’s fixation deepens and she begins to spy on Emily through a telescope, watching her every move.
When Emily unknowingly hails a taxi driven by the very man who attacked her, he strikes up a conversation "because you look familiar." The sense of danger returns with brutal immediacy, and Emily is left trying to regain control of her life in the face of manipulation and fear.
She asks the taxi driver to stop at a phone booth, then calls the police for help. The officers advise her to re-enter the taxi and engage the man in harmless conversation while they close in, a tense plan that underscores the seduction of routine in a dangerous game of cat and mouse. The moment of truth arrives as the taxi driver is arrested and confesses to the entire plot, exposing Andrea’s carefully constructed web of control.
A confrontation follows: Andrea professes her love for Emily, but the revelation only deepens Emily’s resolve. She delivers a sharp, definitive rebuke — a hard slap that leaves Andrea devastated and crying as Emily asserts that they will never speak to each other again. With the immediate danger past, Emily stands strong at her front door, greeted later by the steady presence of [Detective Swid], signaling a fragile sense of safety returning to her life.
