The movie opens one week before Halloween, introducing us to Peter, a quiet kid who has
no friends or any social life.
He lives with his parents, Mark and Carol, who live in an old house located in town,
and he is their only child.
One night, when the 8-year-old boy sleeps peacefully in his room,...
Out of the blue, a noise wakes him up.
He looks around, but finds no one in sight.
Attempting to shrug it off, he tries to get back to his sleep, but the noise returns,
now even louder.
Scared and afraid, Peter turns on the lights.
Strangely, the noise seems to be coming from behind the wall!
So, the 8-year-old gets up, goes towards the wall and knocks on it.
But something strange happens;
he gets the reply of his knocks.
Terrified, Peter goes to tell his mom about the noise, so they go to his room to check,
but his mom doesn't hear anything weird.
She explains that old houses can make odd sounds, and reminds Peter that his imagination
can sometimes make things seem scarier than they really are.
It's the next day, and we find out that Peter, who is introverted, is constantly the target
of his classmates' bullying.
At school, the principal introduces the children to their substitute teacher, Miss Devine.
Later, Peter decides to stay inside during recess at school to avoid getting bullied
outside of the classroom.
His substitute teacher Miss Devine is nice and lets him help with decorating the classroom.
Suddenly, a spider shows up, and startles Peter.
Seeing this, Miss Devine catches the spider in a glass, and helps the young boy let it outside.
This small act of kindness helps Peter feel a bit better.
Later that day, Peter asks his parents, Mark and Carol if he can go trick-or-treating for
Halloween, but Mark takes the conversation in another direction.
He tells Peter that years ago, when he was born, a little girl who lived there disappeared
on Halloween night.
She went trick-or-treating, but never came back.
Carol adds that the whole neighborhood was really shaken up by it, and she doesn't like
to think about it.
Because his parents won't let him go trick-or-treating, Peter has no choice but to spend the evening
in his room.
Later, while Peter is asleep, something even stranger happens; we see a bump on the wall.
All of a sudden, a voice comes from behind the wall in his room and says his name.
The voice asks Peter don't tell him, but he gets terrified, and quickly calls for his dad.
Peter tells Mark what he heard, so the father investigates, but he hears nothing, so he
thinks it might be rats making the noise.
The next day, Mark and Peter go to the shed outside, and get some rat poison to deal with it.
During this, Peter mentions that it smells like cinnamon, but Mark warns her not to eat it.
Mark mentions that the rats will die if they eat the poison, and seems to believe that
Peter is only scared of rats, and doesn't realize there might be something more frightening going on.
At school the following day, the substitute teacher, Devine, notices a drawing Peter did;
it's a picture of a kid asking for help in a dark room.
This catches Devine's attention, and she gets worried.
So, she decides to pay a visit to Peter's house to check on him.
She introduces herself to Carol, and shares with her that while other kids painted monsters
and witches for Halloween, Peter painted this.
Asserting that Peter has an overactive imagination, Carol says that this is embarrassing.
After Devine leaves, Carol asks Peter about the painting, but Peter only responds that
it is merely a frightening image from his imagination when, in actuality, the voice
from behind the wall told him to draw it.
Later that night, Peter wakes up when he hears
a knock on the wall and a voice behind it calling his name.
The voice suggests they become friends, but if he doesn’t want one, she will just leave.
Hearing this, Peter, who has no friends, decides he wants to talk and asks her to stay.
The next school day arrives and we see Peter crafting a Jack O'Lantern that he proudly
names Hector.
His teacher Devine praises his creation, and says that his craft is her favorite.
But trouble brews when a bully named Brian, who's been listening in gets envious.
During recess, Brian's jealousy takes a nasty turn; he shoves Peter, causing him to fall,
and then mercilessly crushes Peter's pumpkin.
Back home, in the comfort of night, the voice asks why Peter is crying.
Tearfully, Peter admits that he's being bullied by a boy named Brian.
In response, the voice advises him that he’s got to learn to stand up for himself.
The very next day, Brian walks into the classroom with a pumpkin in hand, and apologizes to
Peter for his actions.
Peter, however, keeps hearing the whisper suggest to him that he should make Brian scared of him.
Fueled by the whisper's encouragement, Peter trails Brian, and pushes him down a flight
of stairs.
But the outcome leaves Peter horrified – Brian's leg is broken.
Now, things take a turn for Peter; he faces expulsion from school.
At home, Mark, his dad, wants an explanation, so Peter opens up, saying he didn't intend
for Brian to fall down the stairs.
Carol then mentions that Peter's drawing of a child asking for help, and Mark asks
Peter why he would draw something like that, but Peter insists it's because he actually
heard the girl, referring to the voice behind the wall.
In frustration, Mark tells Peter that he’s grounded, and then he moves the refrigerator
behind, which is the door to the basement.
As punishment, the father asks him to sit there, and Carol tells him that they are doing
this because they love him, and they lock him in the basement.
Alone in the basement, he tries to reach out to the mysterious presence, but he's met with
silence, and this moves him to tears.
Later, something intriguing unfolds in the basement.
Peter discovers a strange thing – a pit covered by a grate, and inside, there's a
peculiar doll.
In the next scene, Devine decides to pay Peter another visit, following his expulsion from
school.
She pens her phone number on his math quiz, and heads over to his house with it.
Mark greets her and invites her inside, but Devine is a little uneasy when she sees Mark
holding a hammer.
He even offers her a cup of coffee, but as they talk, Devine notices that Mark is bleeding,
so Mark explains it's just from doing some home repairs.
During their chat, Devine brings up Peter's schooling, so Mark tells her that Peter will
be homeschooled because Carol is an excellent teacher.
Devine gently suggests that Peter might benefit from a different learning environment due
to his recent behavior.
but Peter's parents are adamant that they won't send him away and believe he needs his family.
When Devine asks if she can see Peter and wants to make sure Peter is okay, the get
into an argument.
Peter can hear the argument from the basement, and he comes upstairs, knocking on the door.
The boy repeatedly yells for help, but the noise of the washing machine keeps the teacher
from hearing him.
At that moment, Mark tells Devine she should leave, but as Devine is about to go, she turns back.
She asks Mark about the banging noise, and Mark replies that it's just the washing machine.
As evening falls, Carol brings some pumpkin pies to Peter, and lets him know he can finally
leave the basement.
She gives him a bath to freshen up, and then Mark asks Peter if he's had time to think about things.
Peter nods, indicating he has, and Mark suggests that he should stop telling stories that aren't true.
The parents are proud of him, and they let him know that he won't be going back to school anymore.
Later that night, Peter goes to the wall and knocks on it, hoping to talk to the voice.
Surprisingly, the voice replies.
He tells her about being locked in the basement by his parents, and the voice warns him to
be cautious around them, as they might not be as they seem.
Peter then expresses his desire to see her, but she declines, sharing that she's been
trapped there for a long time and he wouldn’t like her looks.
The voice also reveals a secret – there's a hole behind the wallpaper.
Encouraged by her words, he peels off the wallpaper and discovers the hidden hole.
He tosses his ball into it and, to his shock,
He questions the voice about her identity, and she drops a surprising bombshell – she's
his sister, Sarah.
Sarah discloses that she had to wait, until Peter was big enough to move the clock that
conceals the door, so he could help her escape from the darkness within the wall.
She further reveals that Mark and Carol are evil, and Peter’s time is coming.
Later, as the night deepens, Peter is startled by knocking on his door.
But when the door swings open, there's no one in sight.
Just then, he spots his mother stepping out of the bathroom, and suddenly, the lights
throughout the house go out.
The boy calls for his dad, only to witness his parents taking on a horrifying, demonic appearance.
Peter wakes up the next morning to find his
mother by his bedside; she comforts him, saying it was just a bad dream.
As night falls again, Sarah persuades Peter that his parents are plotting to kill her
once they're done with her, and then they'll imprison him within the walls.
Peter is skeptical, and so Sarah says they've already done so, and urges him to check what's
hidden in the garden.
Driven by curiosity, Peter embarks on digging in the garden the next day.
His heart races as he uncovers a human skull.
Unbeknownst to him, Carol is looking for him in his bedroom and peeking through his bedroom window.
But before she can intervene, Peter hastily buries the skull.
When she asks him what he is doing, he turns around with a pumpkin and says he is thinking
of carving it.
Later on, Sarah reveals to Peter that the fateful day was Halloween before they locked
her inside the wall.
Determined, Peter declares he'll get her out, convinced he knows someone who can help.
Taking action, Peter goes to his parent's room, and aims to use the phone.
He dials up Miss Devine for assistance.
All of a sudden, a noise startles him, and he finds his mom standing right there behind him.
In a hurry, Carol explains that Peter was just telling her how much he misses his teacher,
and she hangs up and confronts Peter about his attempt to reach out to a stranger.
She leads him back to his room, and expresses disappointment for his action.
It's during this moment that she spots the peeled wallpaper,
and investigates the hole behind it, only to leave in fear.
She suddenly warns Peter that whatever happens from this point on is all his fault.
Later that night, Sarah offers Peter an advice; he must do something about his
parents or risk sharing her own fate.
Summoning his courage, Peter descends the stairs, and quietly observes his parents in
serious conversation.
Mark voices his concern about the temporary solutions they've been resorting to.
Mid-conversation, Carol spots Peter eavesdropping.
Caught in the act, Peter rushes back to his room, but Mark sees through the act and he
tells Peter that he'll be there to help Peter out in the garden when he returns home the next day.
The following day, we see them in the garden; Peter notices that Mark has already dug up
the garden, and perhaps he had disposed of that skeleton as well.
Mark explains that black rot is rapidly spreading throughout the garden, killing everything
in its path.
They are going to bury the pumpkins, and are hoping that the next crop will be better.
Meanwhile, a new threat emerges as Brian and his cousins arrive at the house, seeking revenge
against Peter.
Later that evening, during dinner, the doorbell rings, frustrating Carol, who goes to answer it.
Trick-or-treaters stand outside, but she scolds them away and returns to the table.
Mark then remarks about the soup, and Carol notices its unusual smell, somewhat like cinnamon.
It is at this point that Mark realizes something is off and observes that the shed door is
open, while Peter hasn't touched his food.
The father questions Peter if he has done something, but Peter remains silent, frustrating
Mark further.
Peter tells Mark that Mark hurt his sister; the parents are shocked to hear this, and
Mark knows that Peter snuck rat poison into their dinner soup.
Suddenly, Mark begins to groan, and he asks Carol to call 911, but Carol finds the phone
cord cut.
Amid the chaos, Mark succumbs to the poison and dies.
It is at this point Carol discovers what Peter has done.
Seizing a knife, Carol chases Peter upstairs, but the mother also becomes unwell and starts
to vomit blood.
Peter gets away from her by kicking his mother down the stairs, and he sees that Carol stabbed
herself by accident with the knife.
As he turns to leave for his room, Peter bends to retrieve the keys from his mother.
However, as he does, she wakes up, grabs his leg and urgently warns him, "Don't let her out,"
but he ignores her.
Inside the room, he approaches the clock, which Sarah has directed him to.
He tells her he's brought the keys, and she instructs him to move the clock.
As he attempts this, the clock topples and shatters, revealing a hidden hatch, and Sarah
prompts Peter to open it.
However, as he's about to unlock it, Sarah loudly bangs on the door and startles him.
The hatch door slowly creaks open, and Sarah crawls out into the dim room, while Peter
runs into another room.
But something is different – she does not appear human.
She comes to Peter’s room and tries to open the door, and asks him what was it like watching
his parent's dying.
All of a sudden, the doorbell rings and the entity leaves, and we see Brian with his cousins
standing outside the house to teach Peter a lesson.
The door opens on its own, and one of them says let's get this done.
Four of them enter the house and start looking for Peter, and he hides under his bed in fear.
We see one of them enters Peter's room, while the others wreak havoc on the house.
Amid the chaos, Brian slips and falls.
The guy who was breaking the piano is leaving there, when he hears some sound.
And then he sees hair sliding down from the piano, right when that thing throws him down,
and kills him.
In Peter's room, the other boy discovers Peter hiding under the bed, but before he could
catch him, he hears his brother's voice, so he leaves.
In the meantime, Brian is paralyzed by fear as he discovers Carol's lifeless body.
To compound his terror, the door abruptly closes on its own, and another cousin rushes
out, pursued by Sarah.
She drags him away as he pleads for help.
The entity kills each of the boys one by one, until it is Brian's turn.
Suddenly, spiders start descending upon Brian, and he finds himself face-to-face with Sarah,
who goes ahead to kill him.
Meanwhile, in a separate scene, Miss Devine is driving to Peter's house.
On the other hand, Peter is horrified to see that Sarah has beheaded one of the boys.
She then comes out of the room and starts crawling toward him, and tells him that when
he was born, they were so happy, but when she was born, they screamed.
As a result, the father dug a hole for her and put her in a cage.
While he was whining in this warm bed, she was suffering among cobwebs and rats, learning
how to climb, how to bite, and how to make him do what she wants.
She then drags him away and locks him in the room where she came out from.
Back to Devine; she arrives at Peter's house, where she sees the door is open.
As she enters, cries echo, and she spots a shadow in the kitchen.
Observing the disarray, she tries to call 911.
Suddenly, she hears a noise, and glimpses Sarah's hair.
Before she can react, Sarah scratches her leg, and this is when she encounters the sight
of Brian's cousin’s body.
Sarah crawls toward her, causing Devine to scramble to flee, only to discover the door
is locked.
In a critical moment, Peter's voice breaks through, urging Devine to run.
Driven to help him, she races towards Peter’s room, and tries to break the wall.
She manages to break through the wall, and then she and Peter run out of the house.
Unfortunately, as Devine rushes outside,
After some time, Peter wakes up to find himself confined in an underground chamber.
There, he discovers her soft toy.
Not long after, Sarah herself emerges, crawling toward him.
Curiosity overcoming his fear, Peter asks why she is acting this way, so Sarah says
not every child can be as perfect as him; she was just born this way, and no one loves
a monster.
Just then, Miss Devine arrives, searching for Peter.
Sarah emerges from the chamber and trips Devine, attacking her.
In a daring move, Peter takes hold of Sarah's long hair, using it to pull himself out of
the basement hole.
Devine seizes the opportunity, and goes on to attack Sarah with a rod.
As a result, Sarah falls back into the chamber.
And before she can climb out, Peter locks the lid.
Sarah then speaks in a child's voice, pleading for her freedom, and asks him if he really
thinks that this will keep her down here.
Every creak, every groan, and every tap on
the wall will make him think of her, and she says they'll be together forever.