Late at night in Ohio, Rose and her husband Christopher are looking for their adopted daughter, who sneaks out of the house whenever she has nightmares and sleepwalks. Rose runs through the forest and under a bridge to find Sharon on the edge of a cliff. Sharon looks down and has a vision of a burning place with a girl inside that makes her whisper “home”.
Before she can jump, Rose tackles her to the ground. At the same time Christopher almost gets hit by cars when he crosses the road to join his family. Sharon keeps squirming on the ground, repeating the words “home” and “Silent Hill” like every time she has these episodes.
The next day Rose tells Sharon that she’ll take her to Silent Hill to try to solve her issues, even though Sharon never remembers what she said while sleepwalking. Later when Christopher comes home from work, he keeps calling Rose but she won’t pick up. However he finds her search for Silent Hill on the computer, learning that it's a haunted town in West Virginia and it's full of underground fire.
That night, Rose stops at a gas station and notices that Sharon’s drawings have changed from cute into horrific things, including a weirdly shaped cross. Rose asks Sharon about it and the girl freaks out because she doesn’t remember doing it. As Rose calms her down, officer Cybil watches nearby.
When Rose goes inside to pay, she asks for directions to Silent Hill and the clerk says the road doesn’t reach that town anymore. She also tells Rose that her card was declined. Rose immediately calls Christopher, who confirms he blocked the cards and says Sharon will be better at a hospital with medication.
Rose just points out that medication never worked and hangs up. Outside, Cybil approaches Sharon to check she’s fine but Sharon knows to ignore strangers. At that moment Rose comes back and drives away.
Moments later on the road, Cybil tries to make Rose pull over. At first Rose stops the car, however she sees a sign marking the way to Silent Hill and decides to speed up to escape from Cybil. There’s a fence blocking the bridge but Rose just drives through it to keep going.
As they approach a foggy area, the radio starts screeching with static and Sharon screams in pain as she covers her ears. Suddenly a girl appears in the middle of the road and Rose has to turn the car to dodge, causing the vehicle to slip away and crash. When Rose wakes up, she discovers Sharon is missing and that she’s on the outskirts of Silent Hill, where the fog is even thicker and it’s constantly raining ash.
Yelling her daughter’s name, Rose runs down the road and enters the town, which seems to be empty. She sees a small figure running by and Rose follows her into a dark alley at the same time a siren starts wailing through town. A heavy darkness takes over the alley and Rose takes out her lighter, which doesn’t help much.
She hears a voice whispering “mommy” and keeps on searching until she finds an abandoned stretcher. Someone moves again nearby and Rose follows again, but she freezes when she finds a mutilated person wearing mining gear and hung on the fence by wires that make it bleed all over the floor. Suddenly a monster called Grey Child appears behind her and glows when it tries to touch her.
A screaming Rose runs away as more Grey Children show up, but she finds the way blocked by the fence. The Grey Children soon surround her and tear her jacket off as they try to hurt her. Eventually Rose finds an exit and pushes a door to enter a building, however she trips and the Children surround her again, trying to grab her to keep her from moving.
Rose yells in fear and the Children start disintegrating as she passes out. Moments later Rose wakes up inside an abandoned bowling alley where music is playing. She immediately runs out and tries to leave the town, only to find an abyss of fog cutting the road off.
Suddenly Dahlia appears behind her, explaining only the Dark One can let people in or out of Silent Hill. She also shares that she had a daughter called Alessa but she lost her after “they” made terrible things to her. When Rose shows her a picture of Sharon, Dahlia says that’s her child and tries to steal the locket.
Rose has to push her off to be able to run away. Meanwhile Christopher is trying to follow Rose’s route and asks a man at the gas station for directions. The man explains that Silent Hill is closed off because the mines are still burning underground, so Christopher has to bribe him to get proper directions.
Back to Rose, she manages to find her car and one of Sharon’s drawings, which shows a school. The car won’t start, so Rose calls Christopher and leaves a message on his voicemail. At that moment Cybil shows up and arrests Rose, then she tries contacting her station but her radio isn’t working.
Rose notices the cop is bleeding so Cybil explains she also crashed and woke up here. In the meantime Christopher keeps driving while listening to Rose’s message, which is mostly static. Eventually he finds the fence that Rose drove through and a bunch of cops blocking the bridge.
He explains the situation and Inspector Thomas tells him they found Rose’s car at the end of the bridge, but it’s empty. Thomas also shares one of his officers is missing and he suspects she’s with Rose, so he agrees to help Christopher with his search. In Silent Hill, Cybil tries to bring Rose to her station only to discover this road also ends in an abyss, confirming Silent Hill is in the Fog World which is a different reality.
Cybil decides to go back with Rose, hoping to find a radio in town. They see someone moving nearby and when they try to follow, Cybil’s radio and Rose’s phone start making static noises. At that moment another monster appears and Cybil takes out her gun, but before she can shoot the monster throws boiling acid at her.
Thankfully it falls on her helmet and she takes it off to then open fire. While Cybil defeats the monster, Rose uses the chance to run back to town. Following the maps on the bus signs, she navigates the streets and finds the school from Sharon’s drawing.
As she goes inside, she notices the same cross on the door. She makes it to an office and grabs a set of keys plus a flashlight to continue her search. On the street, Christopher and Thomas pass by on the police car, using the megaphone to find Rose.
But since they’re in different realities, they aren’t heard. Thomas reveals his father used to own the barber shop and died during the fire in the underground mines, which caused all the locals to leave the town. Some people think this town deserved its end.
Back to Rose, she suddenly sees a bird inside a cage and a bunch of miners appear holding it. Rose tries the doors but they’re locked, so instead she runs through the backyard and enters a burnt building. She hides in a classroom where she finds two fresh handprints on the dust, revealing the word “witch” written all over the desk.
Inside the desk, Rose finds a notebook belonging to Alessa, which triggers a flashback showing all the students calling the girl “witch” while mocking her and throwing things at her. At that moment Rose sees a girl run by and follows her upstairs into a bathroom, where she hears a girl crying. Rose tries every stall door and in the last one, she’s horrified to find the janitor’s body wrapped in barbed wire with a piece of a hotel keychain in his mouth.
The wall says “double dare you” with an arrow that points at the mouth, so Rose swallows back her disgust and takes the key. When she leaves the bathroom, she notices the miners coming, so she runs back and locks the door behind her. The miners start pounding on the door, but suddenly the bird gets upset and the group runs away.
Then the siren starts again and the room is filled with darkness. Rose uses the flashlight and watches how the bathroom begins to rot and darken. The janitor comes out of the stall and ejects his blood on the wall.
Rose starts running, finding more bodies on her way out. Downstairs there are creepers covering every wall and attacking the miners. A screaming Rose takes another corridor that is blocked by a fence, so she goes around the corner and is shocked to find the burning mine.
She quickly crosses a bridge and looks up to find a creepy-looking Alessa making more dark drawings before she falls off. Rose lands on the backyard, where she sees Pyramid Head before she runs away. At that moment Thomas and Christopher arrive at the school, walking through the same corridor as Rose at the same time but they don’t see each other because of the different realities.
Christopher swears he felt Rose’s presence and even smelt her perfume, but Thomas doesn’t take him seriously and forces him to leave. Rose collapses in tears as a swarm of creepers approaches, but before they can hurt her she’s dragged into another room by Cybil. The cop steps on a creeper while holding the door close and Rose uses a metal bar to lock it.
Cybil uncuffs Rose while explaining she doesn’t have many bullets left. Suddenly Pyramid Head’s blade bursts through the door and the duo dodges it just in time. He tries again and starts making the hole bigger, allowing the creepers to get in.
Then Pyramid Head reaches inside to remove the bar, so Cybil shoots his arm. This doesn’t stop him, however before he can come in all the creepy things start disintegrating. Pyramid Head disappears and the school looks normal again.
Afterward the duo agrees to find the hotel from the keychain. Meanwhile Thomas makes Christopher leave town and tells him to leave this to the cops. However Christopher can tell they’re hiding something and calls the county archives to ask about Silent Hill, but they tell him it’s classified.
That night, Christopher waits for the workers to leave and breaks into the archives. From Thomas’ reports, he confirms the story of the fire and finds a picture of Dahlia’s daughter Alessa, who looks just like Sharon. On the other side, there’s information about a case of kidnapping and assault that happened in room 111 of the hotel.
In Silent Hill, Rose and Cybil find the hotel and hear a woman screaming for help. They find Anna throwing stones at Dahlia while yelling things about faith and doom. The duo quickly stops Anna and Dahlia runs away.
Anna explains Dahlia was cast out and calls her a sinner, she also reveals she’s here looking for food for the survivors that live in the church. Rose takes a knife from her while noticing the weird cross on the floor, and Anna clarifies it’s the symbol of their faith. Inside the mailbox for room 111, they find one of Sharon’s drawings so they go looking for that room.
They check every door but can’t find 111. There’s a painting that Anna calls “the first burning”, which shows all the witch burning this town did to keep darkness away. Rose notices the painting matches Sharon’s drawing and starts destroying it with the knife, finding room 111 behind it.
There’s a hole in the wall and the women jump through it to reach another building, dropping the knife in the process. Suddenly a little girl runs by and Rose follows her by jumping on some old debris above a hole. She almost falls but quickly recovers and reaches the girl, who happens to be Alessa.
Rose asks about Sharon and Alessa responds by showing the flames on her arms that suddenly grow large. When Rose blinks, Alessa disappears. Cybil finds her and throws a rope to help her jump over the hole again, then Rose shares her conclusion: it was Alessa who made them crash and guided them to this place.
While Cybil notices another cross, Anna asks them not to say Alessa’s name. At that moment a bunch of birds fly out of the hole and Anna announces they must leave because darkness is coming. The trio runs through the streets as the siren wails again and they make it to the church, which Rose recognizes from the drawings too.
Suddenly tons of survivors show up to hide in the church except for Dahlia, who tells Cybil not to follow them because these people are manipulating and deceiving. Anna throws a rock at Dahlia as she calls her a liar, but Rose tries to get information out of her anyway. Soon the darkness starts taking over the place so Cybil drags Rose into the church.
A furious Anna stays to throw another rock at Dahlia but she’s caught by Pyramid Head, who rips her skin off and throws it at the church’s door. Inside, the locals start calling Rose and Cybil “witches” and try to push them out, ripping off Rose’s locket. Cybil shoots her gun to make them back off as the leader Christabella arrives to calm her people down, reminding them the Anna died because she broke the rules and not because of two strangers.
For the next few hours, Christabella and the group do nothing but pray. Meanwhile Christopher visits the orphanage where he adopted Sharon, but the nun in charge refuses to share any details about the baby’s past. Christopher snaps and gets aggressive, however he’s interrupted by Thomas who handcuffs him for breaking and entering.
Then Thomas explains Alessa died on the night of the fire and that the cult that lives in Silent Hill did horrible things to her. He shows the burn scars on his hands as he explains some kinds of justice are up to god before sending Christopher home, telling him to drop his search or he’ll end up in jail. When the darkness hours are over in Silent Hill, Christabella finally talks to Rose and Cybil.
She tells them that a demon controls the town and that Rose must face it if she wants to find Sharon, but nobody who tried has ever come back. Rose is determined to do it anyway, so Christabella and some miners take her and Cybil to the local hospital. She makes Rose memorize the map while explaining that this is the demon’s domain and that the darkness lies in room B151.
The miners open an old elevator and give Rose a flashlight, Christabella also returns her locket. However when she sees Sharon’s face, she notices she looks like Alessa and accuses Rose of being a witch. She orders the men to stop her, so Cybil fights them while pushing Rose into the elevator.
One of the guys reaches inside and grabs Rose by the hair, but Cybil brings him down and closes the door. Unfortunately when she fires her gun there are no bullets, so the miners surround her and brutally beat her up. At the same time the elevator goes down and Rose reaches the basement, where she recites the directions she memorized to navigate the corridors.
Suddenly she finds a bunch of dark nurses who start to slowly move toward her, but they freeze when Rose turns off the flashlight. She starts sneaking past them, which only goes well for a few seconds. The nurses wake up and try to kill Rose, who dodges their attacks and causes them to hurt each other instead.
Rose crawls to go through the group unnoticed and leaves the flashlight behind to keep them distracted, then she can run again. When Rose crosses the door of room B151, she hears Alessa’s voice saying she’ll be rewarded with the truth and a flashback begins. Alessa grew up without a father and the religious locals judged her for being a bastard, which caused the other kids to call her a witch.
Even the janitor was abusive toward her. Christabella convinced Dahlia that Alessa could be purified and her cult gathered at room 111 for the ritual. Dahlia was devastated to discover she had been lied too and Christabella intended to burn Alessa like a witch.
However the device they used for the witch burning malfunctioned and started the fire that destroyed the town. Dahlia tried to rescue her daughter but it was too late, and Thomas hurt his hands bringing out Alessa’s burnt body. The girl was kept in the hospital, where her pain fed her anger.
Eventually that anger became powerful enough to manifest herself into a ghost and she covered the town with darkness as revenge. When the flashback ends, Rose finds herself in Alessa’s hospital room. Her burnt body is still on the bed and her ghost appears next to her old nurse.
Alessa explains that Sharon is the manifestation of the little goodness that was left in her, and she abandoned her in the outside world to protect her from the Silent Hill curse. Christabella wants to “purify” Sharon too, so Rose agrees to help Alessa get her revenge. The ghost hugs her and enters her womb while it’s revealed the nurse has been bleeding from her eyes all these years.
Meanwhile it’s revealed that Sharon has been staying in Dahlia’s apartment. Christabella arrives with her men and Sharon tries to hide while Dahlia defends her, but the guys are stronger and easily kidnap them both anyway. Moments later the cult is gathered at the church, where Christabella starts a fire.
Cybil has been tied up to a ladder and the group lowers her just enough to keep her above the fire and burn her very slowly. Soon her body catches on fire and she dies. Next the cult ties Sharon up too but before they lower her, Rose arrives and starts sharing the whole truth.
Christabella’s ritual have never kept demons at bay, it actually created one. Some of the townspeople strike Rose as she walks by, but she never gives up and yells that this faith brings death. Suddenly Christabella stabs Rose and calls her a blasphemer as she drops the knife.
The blood drips on the ground and allows Alessa to spread the darkness inside the church, which used to be off-limits for her. The locals turn on their flashlights and watch how darkness pours out of Rose’s wound, which rots the floor to reveal the burning mines. As Rose’s wound heals itself, a bunch of barbed wire raises from the ground to bring up the burnt Alessa on her bed.
Those wires grab Christabella and go up her groin to then burst out through her belly, killing her before splitting her body in two. Then the wires start killing all the cult members, including the guy that is about to attack Rose. While Dahlia admires what her daughter has become, Rose saves Sharon and takes her to a corner, where the girl sees ghost Alessa approach her before passing out.
Minutes later, sunlight enters the church, which is now clean and empty except for Dahlia, Rose, and Sharon. Dahlia wonders why Alessa didn’t kill her and Rose explains a mother is God in the eyes of her child. Then she and Sharon return to her car, where Sharon finally falls asleep without having any nightmares.
Rose drives while calling her house to leave a message, which arrives with only static. In the city, Christopher is having a nap but wakes up when he senses someone nearby. At the same time Rose and Sharon arrive at the house.
However when Christopher goes outside he finds nobody, yet his family is inside the house. This means Rose and Sharon are still in the fog world because nobody ever truly leaves Silent Hill.
