388 Arletta Avenue

A mysterious intruder secretly records James and Amy, uses a spare key to gain entry, and begins observing their routines. He installs hidden cameras in every room to monitor their movements and dynamics.

The stalker sets up cameras in multiple rooms and subtly tweaks the home alarm to trigger earlier. He also leaves a cryptic mix CD in the couple's car to seed unease and manipulate their routine.

The early alarm wakes Amy and triggers a tense argument about an unseen intruder and the mysterious CD. The dispute exposes growing mistrust and sets a strained tone for the day.

James discovers audio tracks on his computer that hint at someone meddling in their life. Amy insists she didn’t download them, worsening the rift between them.

James drafts a brief apology before leaving for work. The stalker intrudes again, reads the note, and records Amy reacting to noises around the house.

James returns to find a note in Amy’s handwriting saying she left to clear her head. He grows desperate to contact her as she remains unreachable.

James reaches out to Amy’s sister Katherine and their friend Alex, and hints at a past acquaintance Bill. He files a police report, but officers are skeptical and offer little help.

James tracks down Bill, a veteran who now works nights at an animal shelter; Bill reluctantly accepts an apology but hints at unresolved history. Taunting emails and odd behavior from the family cat heighten James’s paranoia.

James finds the decapitated cat and surveillance footage showing an intruder entering the home. He reports the evidence to the police, but the case remains insufficient to act on.

Frustrated and paranoid, James, with Alex’s help, buys a handgun illegally for protection. The escalating fear increases tension as the stalker closes in.

The unseen stalker confirms his presence in the house, triggering a tense pursuit. James offers a deal: Amy’s safe return in exchange for dropping the investigation and not going to the police.

At work the next day, James sees Amy asleep in their bed on video, but Katherine and a police officer arrive to uncover Amy’s body hidden in the basement. James discovers he has been framed for her murder.

James confronts the stalker as authorities close in and is shot dead by a police officer. The stalker labels the surveillance tapes and quietly prepares to begin a new cycle.

The stalker re-labels a surveillance tape with '388 Arletta Avenue' and starts the cycle again with a new family, completing the pattern seen throughout the film.