There's Someone Inside Your House

In the small town of Osborne, Nebraska, a high school junior named Haley Whitehall comes home to her family's farmhouse and finds an egg-shaped timer on the welcome mat. Over the course of the evening, the timer keeps appearing in places she does not remember putting it. She falls asleep and wakes in the dark to find the timer ticking on her nightstand, where her phone had been. It goes off. Haley is murdered in her bed, her throat carved with five deep cuts arranged to resemble a smiley face with X-shaped eyes.

The next morning, the school buzzes with the news. Makani Young, a senior who moved to Osborne from Hawaii the previous year, discusses the murder with her two closest friends: Darby, a transgender boy, and Alex Shimerda, a trumpet player in the marching band. Makani lives with her paternal grandmother, Grandma Young, a retired history teacher. She was sent to Nebraska after a mysterious incident and had her surname changed from Kanekalau to Young to make herself harder to find online. Her parents are distant and selfish.

Makani is fixated on Ollie Larsson, a quiet loner with newly dyed pink hair. The previous summer, they hooked up secretly, but on the first day of school, each assumed the other was ashamed, and they stopped speaking. After Haley's murder, Ollie texts Makani, and they begin a real relationship. Ollie joins her friend group, and Makani learns his parents were killed by a drunk driver when he was in middle school. His older brother Chris Larsson, a local police officer, moved home to raise him.

Ollie reads his brother's case files and shares details with the group: The cuts on Haley's throat slashed her vocal cords, possibly targeting her singing talent. Days later, Matt Butler, Osborne's star running back, is murdered in the school locker room. After practice, Matt discovers his belongings missing. A hooded figure, pretending to cry on a bench, stabs him in the abdomen and then the skull. The attacker shows Matt a printed article about chronic traumatic encephalopathy (CTE), a brain disease linked to repeated head injuries, that had vanished from his backpack. The killer carves open Matt's skull and destroys his brain.

The school stays open so police can interview every student. Chris asks Makani about her knife experience and knowledge of anatomy, routine questions that rattle her because of the expunged record she is hiding. Suspicion among students settles on Ollie and Zachary Loup, the school's resident burnout, because they are outsiders. Darby calls Makani to warn her that Ollie could be the killer, since Matt bullied him for years and Haley rejected him in eighth grade. Makani is furious but recognizes Darby's concern as genuine.

The third victim is Rodrigo Morales, an Osborne High student and gamer, home alone while his parents are away. Rodrigo wakes to find his furniture rearranged. A hooded figure stands motionless in his kitchen. The killer stabs him in the heart, saws off his ears, stuffs them in his headphones, and plays Rodrigo's video game for five hours, leaving behind boot and jeans imprints in the blood, the first physical evidence in any of the cases.

Three murders confirm a serial killer. The national media descends on Osborne, and the killer is dubbed the Osborne Slayer. Ollie tells Makani the police believe the murders are deeply personal, committed by someone who knew all the victims.

While Grandma Young is at a sleep specialist appointment in Omaha, Makani invites Ollie over. Afterward, she goes downstairs and notices the flatware drawer she closed is open again, an unfinished jigsaw puzzle is now complete, and every cabinet in the kitchen stands open. The misplaced items she and her grandmother have blamed on each other for months were the work of someone entering the house repeatedly.

A hooded figure steps out from beside the grandfather clock and drops a hunting knife. Makani lunges for it, but he is faster and slashes her left forearm. Ollie charges downstairs and tackles the attacker. Grandma Young, returning early, throws herself at the killer and is stabbed in the abdomen. The killer flees. Ollie identifies the attacker as David Ware, Rodrigo's supposed best friend.

Grandma Young survives emergency surgery but faces weeks of hospitalization. The police determine David entered through the downstairs bathroom window, hidden by an overgrown viburnum bush. Makani and Ollie stay at Chris's house. At the hospital, surrounded by her friends, Makani reveals the secret she has been carrying since Hawaii.

In a flashback, she describes a swim-team hazing ritual that ended her former life. Senior teammates subjected rookies to escalating physical challenges and forced vodka consumption. Makani's mother had failed to warn her about the tradition, so she arrived humiliated and unprepared. Blinded by habanero Tabasco sprayed in her eyes and furious at her best friend Jasmine for grabbing the last water bottle, Makani seized a hunting knife and sliced off Jasmine's ponytail. Jasmine, drunk and panicking, ran into the ocean and nearly drowned before the team captain performed CPR. Makani was arrested and charged with third-degree assault. The charge was dropped and her record expunged, but the online backlash was devastating. Her parents sent her to Nebraska under a new surname.

Her friends react with empathy rather than judgment. They theorize that David targets students who have wronged others, but this theory collapses when the killings continue. During a town memorial on Main Street, Makani, Ollie, and Darby warn Zachary Loup he might be a target. Meanwhile, Caleb Greeley, a senior and marching band member whose family owns Greeley's Foods, having spoken at the memorial, re-enters the store to retrieve a missing hat plume. David is waiting inside and murders him, severing Caleb's hands and placing them over his heart. That evening, David attacks Katie Kurtzman, the student-council president, in her kitchen. Katie fights back but is overpowered and killed. David flees in her car, and surveillance footage shows him hitchhiking back toward Osborne.

Ollie realizes the common thread among victims: Each was exceptionally talented or ambitious, destined to leave Osborne. He remembers that Rosemarie Holt, an Osborne High student and champion barrel racer, recently won a major competition. Unable to reach her by phone, the friends race to Rosemarie's property, which borders a corn maze packed with Halloween visitors.

Rosemarie is alone in her stable when David attacks. She fights him with a pitchfork, gouging his side. Makani and her friends arrive, and in the struggle, David slashes Alex's neck, killing her. Ollie chases David into the maze. Makani and Darby follow, shouting warnings to visitors. They find Ollie wrestling David. Makani kicks David, but he stabs both Darby and Ollie in the chest. Brooke, Haley's best friend working as a Sweeney Todd actor in the haunted maze, douses David with theatrical blood, disorienting him.

David corners Makani and reveals his motive: He resents the students destined to escape Osborne while he feels trapped. Killing them was his twisted plan to achieve his own escape, to prison. Makani ducks his knife and flees to the corn pit, a massive pit of dried corn kernels. Darby, still alive, strikes David from behind, knocking him into the pit. Makani retrieves his knife and, when he lunges, stabs him in the back.

The townspeople surround the pit. David crawls, stops, and dies in Osborne, the place he will be buried. Over the police radio, Chris announces that Ollie is alive. Makani runs back through the maze to find him conscious and smiling on the ground. She kisses him under the autumn moon, and he squeezes her hand.