Pedro, and Jaime, are two brothers who live in a small house in rural Argentina.
One night, as they are about to sleep, they hear some gunshots in the distance.
Pedro, being a veteran hunter, immediately realizes that it’s a revolver;
this means that whoever is out there is not hunting animals.
The brothers then arm themselves, and prepare to investigate the matter.
But at the last second, they have a change of heart because it’s already too dark,
so they decide to check it out the next morning.
As soon as the sun rises, the brothers venture into the nearby forest, from where the gunshots were heard.
After walking for a few minutes, they come across a gruesome sight:
an unknown man's body has been torn apart in half.
Judging by its condition, Pedro deduces that this wasn’t the work of an animal.
He says that this is no ordinary death, so the two brothers start searching the area.
Soon, they discover some documents on the man’s body, suggesting that he was heading
to a lady’s house, which they seem to know.
There's also a copy of the lady's ID with the name Maria in it,
so the brothers set off in that direction to find out more.
In the following scene, Pedro and Jaime arrive at Maria's house, and inform her that the
person she's been waiting for won't be coming because he's already dead.
It’s evident that the person was very important to her.
The lady shares that the guy was supposed to deal with her elder son, Uriel,
and that he must kill him.
Hearing this, the brothers are intrigued, and decide to investigate to find out what she means.
Santiago, Uriel’s younger brother, explains that Uriel has been possessed;
he’s been rotten for a long time.
The family hides this from the neighbors, afraid of being kicked off the land.
To add, they reported this to the mayor a year ago, but only this time he took notice
and sent someone to assist.
The man who was found dead in the woods was actually a religious cleaner, who was supposed
to help them get rid of the possessed Uriel.
Hearing all this, the brothers fear that the entity could become a threat to them, so they
go to the police station to report the case.
However, the officers claim many cases of possessed ones are fake, which enrages Pedro.
He angrily says Uriel is dying and swollen, and after seeing how serious Pedro is,
one of the cops decides to call Public Health.
On the other hand, another cop suspects that the landowner, Ruiz, killed the religious
cleaner in the woods.
The brothers then approach the landowner, Ruiz, and share all the details of the situation,
including the dead man in the woods.
The police will send a new cleaner from the Ministry, but Pedro says Uriel is dying,
and they can’t wait for a cleaner anymore.
Upon learning this, Ruiz deduces that the government causes this to happen, and that
the government, including the police don’t care about the villagers, so they could scare
away all the inhabitants, and use his land for commercial purposes.
Later that day, Ruiz tells his pregnant wife that he doesn’t want anything bad to happen
on his land.
He angrily grabs his gun, and heads to Uriel’s house to finish him off.
But before he can do so, Maria intervenes.
She warns him that if he uses a gun against the entity, it will break free and possess everyone.
It turns out that Uriel is being possessed by an unborn demon, who is awaiting physical birth.
The cleaner called by María was to kill Uriel, and abort the demon before it possesses others.
The entity that possesses Uriel tells Ruiz to kill him, so he can move to Ruiz’s wife’s belly,
and possess the baby inside her.
Hearing this, Ruiz becomes frightened, and he eventually leaves the house.
Afterwards, he explains to the brothers that they need to get rid of the evil force as
soon as possible from their area.
If they are not fast enough, the entity will destroy everything in its path.
The trio forcibly barges inside the lady’s house with the intention of taking Uriel away.
However, it is not an easy task, as the possessed man appears to be huge.
While he is being carried, pus, and other nasty things pour out of his body.
Regardless, the three somehow manage to carry him out, and load him in their van.
Now, they want to take him as far as possible and dispose of him, and they want to make
sure that he never comes near their residence again.
After driving 300 kilometers from their place, Pedro instructs Ruiz to go 100 kilometers farther.
But then all of a sudden, they nearly run over a school boy.
Later on, the three of them decide to catch a breather, and check on Uriel.
However, when Ruiz checks the trunk, the fat man is no longer present;
they search the area, but find no traces of him.
The trio then assumes that his large body might have rolled out when they almost hit the school boy.
Since they have already driven for about 300 kilometers, they believe that it’s a safe
distance and decide to return home.
Unfortunately, the very next day, Ruiz and his pregnant wife discover that one of their
goats has been possessed by the same evil entity.
Enraged and out of options, Ruiz aims his gun at the animal, but his wife stops him.
She repeats the same thing which the old lady said earlier, that one can’t defeat evil using a gun.
Moments later, Ruiz attempts to back off, but at the same time, the possessed goat comes near his gun.
It taunts him to pull the trigger, and this turns out to be a fatal decision, as the evil
escapes and finds another host, which turns out to be their unborn child.
His wife also gets possessed, and she ends up killing both of them with an ax.
Later, Pedro and Jaime are at home when Uriel's brother, Santiago, arrives at their doorstep.
He anxiously tells them that his mother is missing, while both Ruiz and his wife are dead.
The brothers are shocked to hear this, and then the boy requests to stay with them for the night.
Jaime is a bit skeptical about the whole situation so he refuses,
but Pedro agrees to let him stay in the barn.
They then find a revolver on him and confiscate it.
Before leaving, the boy warns them not to use electronic lights, because it apparently
attracts the evil force toward them, but the brothers don't pay much attention to his advice.
The next day, Pedro and Jaime decide to leave the village, but they are afraid to carry any belongings.
They believe that the evil force might be resting in them, which could harm their loved ones.
Before they leave for town, Pedro heads to visit his ex-wife, Sabrina,
while Jaime stays with their mother.
Sabrina now lives with her new partner, Leo, and their daughter.
They also have two sons from Sabrina's previous marriage to Pedro.
Pedro storms into the house, and instructs Leo to tell his wife and children to get ready
to leave with him.
He requests a change of clothes from Leo, who has no idea what he's talking about.
Sabrina believes Pedro is drunk, but Pedro assures them that he will explain later.
While this is going on, Leo's dog is sniffing Pedro's clothes.
Once Pedro gets new clothes, he burns the ones he took off right away,
and then brings Leo and Sabrina inside to talk.
He informs them that there is a rotten, a.k.a.
the evil entity, in town, and that this town will quickly turn into hell,
but the couple remains skeptical.
Meanwhile, Santino, Pedro's son, is told to wake up his brother upstairs, while Vicky,
Leo's daughter, is playing with the dog.
But then, while the parents are arguing about Pedro's intention to take his sons,
they are unaware of what’s going on behind them.
the dog suddenly gets possessed, and attacks the little girl.
Santino witnesses this horrifying incident, and calls for his parents, while the dog harms
the little girl as it drags her outside the house.
The elders quickly rush after them to rescue Vicky, but the possessed being gets away.
We can assume that the dog was possessed after sniffing Pedro’s clothes.
Pedro leaves Leo alone, returns home to calm down his son Santino, and goes upstairs to
wake up his elder son.
It's revealed that his eldest son, Jair, has autism, and he brings him downstairs just
as Leo comes back, without Vicky in sight.
Desperate and angry, Leo grabs his gun, and decides to search for his daughter.
Pedro warns him not to use the gun on the evil, but Leo can’t be stopped because Vicky
is his only child with Sabrina.
When Pedro tries to chase him down, he hears a gunshot.
He soon finds Leo and the dog, but Leo has already killed the dog with his gun.
Witnessing this, Pedro realizes that he must take his two sons, and leave the city as soon
as possible to protect them from the growing danger.
Strangely enough, Vicky returns home, unharmed.
Without wasting any time, Leo enters the house, and loads his sons in Sabrina’s car.
Something odd seems to have happened to Vicky; the little girl says to Sabrina that her father
is going to kill Sabrina by car soon.
Unfortunately, before Sabrina can understand what’s going on,
Pedro witnesses Leo runs her over, and is horrified to the core, so he flees the scene
immediately so that his sons don’t notice what’s happening.
Inside the wrecked vehicle, Leo is badly hurt, but Vicky is happy to see her mother get run over.
Along the way, Pedro picks up his mom and Jaime, and Pedro tells Jaime everything.
Later, Pedro's younger son, Santino, asks about what it means to be possessed, and the
oblivious grandmother explains that possession happens when an evil force
enters a human body, and takes control of it.
She believes that they can be safe from it, as long as they stay away from electronic items and animals.
The grandmother also urges them to avoid the possessed person’s belongings,
never call evil names, and not shoot the evil.
When grandmother continues listing out the evil names, Pedro stops her because she is
violating her own rule.
In the meantime, his autistic son, Jair, starts recalling the names they've been told not to say.
Shortly after, Pedro’s mother receives a call from Sabrina, which is strange because he just saw her dying.
Pedro takes the phone far away from his family, and he answers it, asking what she wants.
Sabrina says that she is coming after their children, and she attempts to manipulate Pedro's
emotions by claiming she cheated on him because no one likes him.
After the call ends, Pedro claims Sabrina is dead, and he is left deeply unsettled.
He feels guilty for bringing evil into Sabrina’s lives and ruining her family.
Seeing him so distressed, Jaime suggests they seek help from a former cleaner named Mirta
that could help them.
A while later, they arrive at Mirta's home, and Jaime explains everything to her.
In response, she promises to help the best way she can and ask them to stay.
At night, Jair refuses to get out of the car, so Pedro stays outside with him, while the
rest of the family sleeps inside the house.
And then all of a sudden…
As everyone is asleep, the grandmother notices Sabrina in her room with her disfigured face,
holding Santino in her hand.
When Pedro and Jaime catch wind of this, Pedro rushes into the room and sees Sabrina,
who is carrying Santino with her, before jumping from the balcony.
Pedro runs after her, but soon realizes she's already gone.
Another problem arises when Mirta reveals that Jair has now been possessed.
She explains that the evil force hasn't completely taken over him yet, because Jair is autistic,
and it can’t control his mind.
Using this opportunity, Mirta opens her cleaning equipment, and explains to Pedro and Jaime
that they need to kill "Rotten" to break the possession process.
She knows that it is alive somewhere and they need to find it.
The brothers then tell her that the first person who got possessed, Uriel, fell from a truck.
Hearing this, Mirta says that moving "Rotten" was a big mistake.
The lady shares the seventh rule to stay safe from being possessed: one should not be afraid to die,
because evil preys on their fears.
She is saying so because the entire family is terrified of losing Santino right now.
She and Pedro then set off to find it, while Jaime goes in search of Sabrina and Santino.
As the group parts in different directions, Mirta tells Pedro about her life.
Her husband was a shepherd who pretended to run a church,
but actually knew nothing about cleaning and "Rotten."
He hired actors to perform fake rituals, until the real "Rotten" showed up, teaching them
a valuable lesson and making them start working for real.
However, he disappeared one day when he attempted a real cleansing.
She has done this for 12 years, which is why "Rotten" stayed away from her.
Pedro wonders why the evil entity didn't take Mirta instead of his son, and she explains
that it is because he is the one who is afraid, afraid of losing his son.
On the other hand, Jaime, who is on a quest to find Sabrina and Santino, finally locates them.
To his horror, he discovers that Sabrina has brutally killed Santino by decapitating him.
In a state of shock and distress, he decides to do this…
He ends up hitting Sabrina with his car, causing injuries to himself as well.
Meanwhile, Pedro and Mirta reach a school while searching for "Rotten."
She shares her belief that "Rotten" must be here because the evil entity is drawn to children;
and children, in turn, are drawn to the evil entity.
On the other hand, we see that Pedro's mother is alone at home, and Jair, who is autistic,
suddenly enters the house, and asks for food like a normal person, scaring the life out
of the poor woman because this is the first time she hears Jair talk like this.
When they enter the school, Pedro turns off his flashlight, and Mirta’s assumption turns
out to be true.
They discover that there are children in the classroom in the middle of the night, sitting quietly,
seeming to have been possessed by the malevolent force.
Mirta asks the kids where the entity is, but the girl keeps refusing to reveal it,
and the lady rushes outside, because she can't stand the smell of the children's breath.
She claims that the children protect the rotten, and then they come across a child who Ruiz
almost hit earlier while carrying Uriel.
Moments later, the kid informs them that Uriel is at a teacher's house, giving them directions,
but he refuses to follow them.
Pedro rushes inside the car, but Mirta warns that this could be a trap, just as the girl
from class appears, and says the boy is telling lies.
She states that Uriel is in her house; her father wanted to help and cure him.
It is at this point that Pedro and Mirta quickly realize that these statements from the kids
are fabrications meant to mislead them.
If the kids send them somewhere else, it’s because they have him here.
Continuing their search, they come across a gruesome scene on the school hall stage.
Under the stage, they find the dead body of a teacher, probably killed by the possessed children.
As Mirta sets up the demon killing equipment, Pedro quickly tries to open the stage wood,
revealing a number of scattered dead bodies, and he takes the dead bodies out one by one.
Hidden beneath these lifeless bodies, they finally spot living Uriel’s body,
where Rotten is residing.
Mirta instructs Pedro to remove Uriel, a.k.a Rotten, from its resting place,
but this proves to be a near impossible task for him.
As Pedro tries to remove "Rotten" from its resting place, he becomes entangled in a psychological
battle with the evil entity.
The little girl tells Pedro that there is an axe in the back room that he can use to murder Uriel.
Pedro, who can't stand it when the entity mentions his son, walks towards the office
to get the axe, while Mirta screams at him not to leave her,
but then he becomes trapped inside.
At the same time, the kids kill Mirta brutally with a hammer while she is left alone outside.
She was the only cleaner who could combat the evil presence to this point.
After a struggle, Pedro manages to escape the room, but the kids have already taken
Mirta's dead body from there.
Uriel pops his head out from beneath the stage and tells Pedro to kill him.
Overwhelmed by grief and anger, Pedro beats Uriel to death with a piece of the broken equipment,
but is too late to intercept the birth.
The demon inside Uriel is born soon after, shedding his corpse, and presenting itself
to a defeated Pedro.
After taunting Pedro by sparing him, the newly born demon walks out into the morning sun,
followed by the children.
Afterward, Pedro and Jaime give up on everything and return home, feeling defeated as the evil
presence has become anchored, infecting the entire city.
As they are contemplating what to do next, they recall that they had locked up Uriel's brother in their barn.
Jaime goes to check on him, and this is when the boy makes a shocking revelation; he says
that a voice compelled him to kill the cleaner who was supposed to help Uriel in the opening scene.
Not only that, the evil entity forced the boy to eat the deceased man’s remains.
He also reveals he did the same to his mother the night before, and alludes that Jaime's
mother has suffered the same fate.
In the final scene, Pedro goes to take a shower after giving ice cream to Jair.
During the bath, he notices that the evil entity's fingerprints on his head have become permanent.
Later, he exits the bathroom, only to discover that Jair is choking, and realizes that something
is obstructing his throat.
When Pedro checks it, he finds a lump of hair, and then his mother’s necklace.
This means that Jair ate his own grandmother, having been possessed as well.
Overwhelmed with despair, Pedro collapses to the ground, and starts crying.
The two brothers reminisce about the people they have lost, and this is where the movie ends.