The 4th Floor

Jane inherits a rent-controlled brownstone and decides to move in on her own for the first time, despite Greg's protests. She hopes for independence, but quickly senses that the building hides more than ordinary neighbors. This move sets the stage for the creeping tension that drives the story.

On the first floor, Jane meets Martha Stewart, who lists the building's occupants and mentions the reclusive Alice on the 4th floor. The chat introduces a web of acquaintances and potential watchers inside the building. The exchange plants a sense of watchfulness that will color Jane's trust in others.

A warning note appears on Jane's door about the noise from moving. She initially dismisses it as petty harassment and continues unpacking. The note marks the first sign that she is not welcome in the building.

Another note arrives after someone tampers with her locks, prompting Jane to call a locksmith. The locksmith is described as odd and living across from Jane, a detail that unsettles her. The encounter deepens the sense that someone is watching and interfering with her home.

Jane and Greg argue about her not moving in with him, highlighting the strain of her independence. He presses her to change her mind while she remains resolute. The dispute foreshadows the isolation Jane will increasingly feel in the building.

The downstairs neighbor smashes Jane's kitchen tiles during a quarrel, and she immediately calls the police. In retaliation, she makes more noise to get back at them. The confrontation escalates tensions and makes her feel attacked in her own home.

The next morning Jane trips on a grease-smeared stair and falls, a reminder of how precarious her situation has become. She writes a simple sorry note attempting a truce with the neighbor. The incident deepens the sense of vulnerability inside the building.

Maggots and mice infest Jane's apartment, prompting an exterminator to come. The exterminator hints the infestation isn't accidental and could be tied to the neighbor. Jane becomes convinced someone is sabotaging her home from within.

A Korean grocer reveals that Alice had stopped ordering groceries, implying something about the 4th floor. When Jane tells Martha, Martha accuses her of disrespecting privacy and authority instead of listening. The building's complicity grows clearer as suspicion tightens around the neighbors.

The exterminator explains that the mice problem was likely caused by a drilled hole in the floor, not a random nuisance. Jane decides to break into the 4th floor to photograph evidence and try to expose what is happening. She prepares to gather the critical clues that could validate her fears.

On the 4th floor Jane finds cages with mice and rats, a typewriter, and a floor plan mapped on the ceiling, with the word Portcullis painted on a wall. The discovery confirms someone has been staging her movements and monitoring her. The scene raises the stakes and clarifies the intent behind the harassment.

Jane receives a package filled with packing noodles and a sorry note reading 'Truce accepted', along with photos of her aunt's dead body. Terrified, she tries to report what she found, but is knocked out by an unknown neighbor and the evidence is stolen. The attack cuts her off from her support network and intensifies the peril.

After the attack, Jane is hospitalized and discovers the drilling hole in her floor has disappeared. Greg urges her to move out and stay with him, undermining her credibility. The episode leaves her more isolated and determined to uncover the truth.

Jane discovers Portcullis markings on Mr. Collins's ceiling, revealing him as her terrifying neighbor. A brutal struggle unfolds across the apartment and staircase as Collins traps Jane and tries to kill her. The locksmith intervenes to help, and in the end Greg arrives; Jane pushes Collins to his death down the stairs, ending the terror.