There's Someone Inside Your House Ending Explained: Who Was The Killer?

Makani Young runs from a killer in There's Someone Inside Your House screenshot
(Image credit: Netflix)

Spoiler alert! This story (obviously) reveals the There's Someone Inside Your House ending. If you haven't watched the Netflix movie yet, proceed with caution!

There's Someone Inside Your House is a teen slasher flick that hit Netflix just in time for blood-thirsty Halloween viewers. Based on the book by Stephanie Perkins and directed by Patrick Brice of Creep fame, There's Someone Inside Your House follows a group of students of Osborne High School, primarily Makani Young, who is relatively new to the small town after moving from Hawaii to live with her grandmother. But when students start getting murdered, exposing the teens' darkest secrets, the whole town of Osborne is on edge. 

This Netflix horror is full of blood and drugs, with even some Nazi stuff thrown in there. And while the movie's conclusion is visually impressive, with the killer being revealed in a surprising twist against the backdrop of a blazing corn field, the murderer's motivations turned out to be a little hard to follow. Let's dive deeper into the There's Someone Inside Your House ending.

Makani and her friends sit at school in There's Someone Inside Your House

(Image credit: Netflix)

What Was Happening To The Students At Osborne High?

The movie opened with its first kill, rather than with our main characters — one of many aspects that gave this movie a Scream vibe — where football player Jackson was stalked around his otherwise empty house, finally falling victim to an Achille's tendon slashing. The killer then alerted the entire town to Jackson's secret — that he bullied his teammate Carter, who was gay. 

A second victim, student council president Katie, was found to not be the holier-than-thou citizen she claimed when the killer uprooted a white supremacist podcast Katie had anonymously recorded, and then strung her body above the church's altar. This put every Osborne High student with a secret at risk, particularly Makani, who moved to Nebraska to escape her own scandal and was constantly worried that the killer had unearthed her true identity.

Zach Sandford stands in front of his dad's Nazi memorabilia in There's Someone Inside Your House

(Image credit: Netflix)

Who Was The Murderer?

So who was the serial killer bent on revealing the Osborne students' biggest secrets? Zach Sandford, one of Makani's friends and son of the businessman who was bankrupting the town, was revealed to be the murderer in a surprising and amusing twist. When Makani and Ollie ran into the burning corn fields to find Zach and save their friend, they witnessed Mr. Sandford being stabbed through the face. The killer then realized he forgot to give Sandford his big speech before killing him, and Zach took off his mask in frustration, revealing to his friends that he was the killer.

This is where it got a little hard to follow. Zach said all of his classmates were hypocrites just like his father. And while everyone else could hide their secrets, Zach's shame lay in the fact that he was born into privilege as a Sandford. Since he couldn't hide his last name, he was going to expose everyone else's true selves as well. He then said he'd planned to frame Makani for the murders, but if that had been Zach's plan all along, it wasn't very well-thought-out, since he had tried to kill her earlier in the movie. 

Killer wears a mask in There's Someone Inside Your House

(Image credit: Netflix)

What Was With The Masks? 

The opening credits showed the unseen killer scanning yearbook photos of his classmates and using the images to create 3D masks of his would-be victims' faces. Zach then wore the masks when taking out his classmates, making it appear like they were their own murderer. He told Makani he did it because everyone wore a mask, and in their final moments, Zach wanted his victims to face their true identities. As cool as the masks looked, even Zach admitted to his friends what a laborious task it was to make them all.

Makani and Ollie stand in a corn field in There's Someone Inside Your House

(Image credit: Netflix)

Why Did Makani Think Ollie Was The Killer? 

Ollie was a loner, and in not having any (known) friends, the Osborne High students all started pointing an accusatory finger at him. Not to mention, Ollie's older brother was a police officer, which his classmates thought gave him easier access to their background information (i.e. their secrets). Nobody knew about Makani's relationship with Ollie, and even though she tried to brush off her friends' warnings, she got spooked when Ollie revealed that he knew her real name was Makani Sun-Woo. Ollie also carried a Taser, which was part of the killer's M.O.

When Makani was attacked with a Taser later that night by someone who knew about her past, she immediately accused Ollie, and he was arrested. When he was released, he found Makani to try to talk to her, and as she ran away from Ollie, she saw the real killer stab Caleb.

Hazing ritual in There's Someone Inside Your House screenshot

(Image credit: Netflix)

What Was Makani’s Secret?

Makani was part of a swim team back in Hawaii, and her secret revolved around a hazing ritual she and the varsity rookies had gone through. They were forced to drink alcohol and do different physical activities on the beach in front of a huge bonfire. Makani said the seniors were trying to make the underclassmen turn on each other. Makani's friend Jasmine pushed her, and when Makani pushed her back, Jasmine fell into the bonfire. She survived but was badly burned. Makani said she went to trial and was acquitted, but she still received daily threats, so the choice was made to move to Nebraska and change her name. 

Zach Sandford stands in front of a burning corn maze in There's Someone Inside Your House screenshot

(Image credit: Netflix)

What Happened To Zach?

After Zach revealed himself to Makani and Ollie, Ollie tried to tase Zach, but the taser jammed. Zach stabbed Ollie and then told Makani how he was going to frame her for the murders. An injured Ollie got the taser to work, and while he missed Zach, it was enough of a distraction that Makani was able to overtake Zach, and she stabbed him. She said blaming others because he was born privileged made no damn sense and she didn't need a mask to show him who he really was. Then she drove the blade into his body, killing him. 

There's Someone Inside Your House is streaming now on Netflix (opens in new tab). Once you're done with that, here are some more 2021 Netflix movies for you to check out, as well as these 2021 new movie releases

Heidi Venable
Content Producer

Mom of two and hard-core '90s kid. Unprovoked, will quote Friends in any situation. Thrives on New Orleans Saints football, The West Wing and taco trucks.