"SHARON! Where are you?" We first hear Rose DaSilva (Radha Mitchell) shouting these words as she and her husband Chris (Sean Bean) search for their daughter Sharon in the middle of the night. Rose runs beneath a highway through some kind of river and finds herself standing over a gigantic waterfall. She sees Sharon (Jodelle Ferland) standing on the other side in a trance (she sleepwalks). We see from Sharon's point of view the world literally falling apart and becoming some kind of hell (think the Hell LA sequences in Constantine). Just before Sharon sleepwalks off the cliff, Rose gets to her and wakes her up, where she starts screaming, "Silent Hill! Silent Hill!" over and over. Chris arrives and reassures his wife and daughter, although it's obvious both him and Rose know it's far from alright.
Two years later. Sharon is leaning against a tree and coloring in a picture of herself and a lion near the tree. Rose comes up and her and Sharon play around a bit. She then tells Sharon about her sleepwalks and how she keeps mentioning Silent Hill. Sharon says that she doesn't remember, but Rose replies with, "That's why we're going there...so you can remember." They leave and head out, passing a sign that basically says angels shall be judged by saints -- people -- and not the other way around. Meanwhile, we see Chris trying to contact his wife, who is continually ignoring his calls (apparently this trip was not made to include him). He begins looking at some of the websites Sharon pulled up on Silent Hill, and he learns that it is located in West Virginia, is considered one of the most haunted towns in America, and that 30 years ago, there was a large underground fire that pretty much killed everyone there.
That night, Sharon and Rose pull into Braham's Gas Station, which is within spitting distance of Silent Hill. As she gets out, Rose notices Sharon's pictures and sees that they've been changed to show people burning in various buildings, like a church or a school. Sharon wakes up and Rose asks her about them, but Sharon starts crying and swears she didn't do them, which a nearby female police officer takes notice of. Rose placates Sharon by saying she can ride up front with her, and then goes inside to pay. The cop comes over and tries to talk to Sharon, but Sharon just rolls up the window and ignores her, saying she never talks to strangers. The cop just smiles and says, "Good girl." Inside, Rose tries to get directions to Silent Hill but is told that the road is closed and her credit card has been declined. She pays cash and then calls Chris. He tells her what he found out, but she just asks him to trust her. Rose heads back to the car, and the cop tries to talk with her, but Rose waves her off and drives away... but not before the cop gets her license plate number.
A little while later, we see Rose and Sharon approaching the Silent Hill turnoff when they get pulled over by the cop from before. She approaches the vehicle just as Rose notices a sign indicating the turnoff is right ahead. She tells Sharon to buckle her seatbelt and speeds off. The cop gets on her motorbike and gives chase. Sharon crashes through a padlocked gate and crosses an old bridge, managing to lose the cop at some point. She keeps heading forward at seventy and rounds a curve just as we see someone step into the road. Sharon warns her and the two girls scream as Rose swerves the car and they crash into the embankment.
The next morning, Rose wakes up with a big bump on her head. She looks around groggily and suddenly notices that Sharon has disappeared. She gets out of the car and begins calling for her as she notices that snow has begun falling... black snow made of ash. She passes a sign that says "Welcome to Silent Hill" and heads into town, utterly lost and disoriented. She wanders the streets calling for Sharon, and suddenly sees a little girl who looks exactly like Sharon running off. Rose gives chase and eventually ends up atop some stairway leading down below street level. She starts descending just as an air raid siren begins sounding from somewhere. Things grow unbelievably dark, and Sharon takes out a lighter. She turns it on and sees that she is now standing atop some grated floor with falling apart walls and... basically it's the same hell world Sharon saw earlier. She wanders around trying to get her bearings and trips over a wheelchair. She stumbles upon an undead guy who has been strung up and gutted, and then she catches another glimpse of the Sharon lookalike. She runs after her but finds a chain-link fence between her and the girl. She turns around and then finds a bunch of gray ghost children behind her. One of them gives a banshee-sized wail and begins attacking her, but she gets it off just in time for a hundred or so more to come up. She runs past them and manages to find a door. The children overwhelm her and she gets the door open. She crawls away and screams, but--
--she wakes up in some abandoned bowling alley where "Ring of Fire" is playing on the jukebox. She looks around, but the gray children are nowhere in sight, and if it weren't for her obvious wounds, it could almost be a dream or hallucination. She runs out of the bowling alley and heads down a street, trying to find someone, but is stopped by an enormous chasm that seems to have simply cut off Silent Hill from the world, even cutting through buildings halfway. She leans over to look down, and then someone behind her says, "Only the dark one opens and closes the door to Silent Hill." She turns and sees a dishevelled and dirty homeless woman there. She approaches the woman, Dahlia Gillespie (Deborah Kara Unger), and asks what's going on and tells her about Sharon, but Dahlia just says "We've all lost our children." When Rose gets more cryptic comments, she pulls out a locket picture of Sharon. Dahlia freaks and claims that the picture is of her daughter. She tries to attack Rose, but Rose hits her and runs away as Dahlia says, "Deep in the fires, she will be buried."
At this point we cut back to Braham's gas and see Chris pulling up. He gets out and asks the station mechanic (Ron Gabriel) if he's seen his wife, but the mechanic claims not to know anything, even when Chris offers a bribe and shows him a picture.
Back in town, we see Rose heading back to the car. She sees a picture of Sharon's blowing on the ground and sees it is of a school. She goes through some other pictures and realizes they're of places around Silent hill. She gets in the car and calls Chris's cell phone. Chris picks up, but all he hears is static. Regardless, Rose says what happened and tells Chris that she is heading for the school. She tries to start the car but is interrupted by the cop, who tells her to get out of the car.
Meanwhile, we see Chris pull up to the bridge, but it is blocked by police. He says that he is Rose's husband and gets through. At the other end of the bridge, he meets detective Thomas Gucci (Kim Coates) and tells him what he's doing there. Gucci tells him that he understands and that he's got an officer on the other side of the fallen trees blocking the road. A deputy named Cybill Bennet (Laurie Holden), who apparently did something famous with a young boy three years ago in that town, and she's probably got Rose in good condition.
Meanwhile, we see exactly what condition Officer Cybill has Rose in handcuffs. Rose is trying to tell her that something is wrong in town, but Cybill is ignoring her and tells her how three years ago she tracked some sick guy into town who went into the mines with a little boy. She rescued the kid and spent three days trapped in there before someone could rescue them. They get back to Cybill's overturned police motorcycle and Cybill tries to radio in, but gets nothing but static. Rose tries again, but instead is forced to march with Cybill to.... another chasm. Rose yells at Cybill about not believing her just as something comes out of the mountains that looks like a person. Cybill takes out her gun and yells at it to halt, but it keeps coming, and we see that it has no arms and gray skin (Michael Cota). It spits some kind of acid at Cybill, who takes it on the jacket and helmet. She rips them off, dodges another round, and shoots the Spitter five times before it goes down. Rose seizes the opportunity and runs back into town, still in handcuffs but now with a clear destination. She finds a map of town on a corner lamppost and eventually makes her way to Midwich Elementary School, whose motto above the school door reads, "The foes of the righteous shall be damned to suffer" or something like that. Rose finds the main office and grabs a set of keys to every door and drawer in the school. She also uses the keys to get a flashlight out of one drawer, which thankfully works.
At this point we check back in with Chris, who is being driven around a bright, fogless, and snowless Silent Hill by Gucci. Gucci is on the P.A. system and is telling Rose to come out. Chris thinks she might respond more to his voice, but Gucci vetoes that, telling him that when a woman steals off in the middle of the night with her daughter, hearing her husband tell her to come out is not something that usually gets them to come out. Meanwhile, we see Rose searching the school when she hears something coming upstairs from the basement. She opens a door and softly calls out and sees a pair of very imposing men -- the miners -- come out. She runs off and eventually ends up in a classroom. She finds a desk with witch carved into it and looks inside. She finds the journal of Alessa Gillespie, and we see a scene of the young girl who looks like Sharon being mocked by her classmates for apparently being the daughter of a witch. Suddenly Rose sees either Alessa or Sharon running past and follows her into a bathroom. Inside, Rose hears the sounds of a little girl crying and figures out which stall it's coming from. She opens the stall but instead of Alessa or Sharon finds a dead naked janitor with dog tags identifying him as "Colin" being held up by barbwire in a contorted position. The wall behind him reads "Dare you dare you double dare you!" and we see an arrow pointing into Colin's mouth. Rose sees something sticking out and reaches through the barbwire to pull out a hotel key -- the Grand Hotel, Room 111. She runs away from Colin and opens the door just in time to be caught by one of the miners' lights. She slams the door shut as three of them head for the door. Rose locks it with her key set just in time for a canary the miners had to start flapping around wildly. The miners look at each other and bolt.
Right after the miners retreat the same siren goes off, and Rose looks around her as the walls literally start melting and changing back into the Hell version of things. Just as things finish changing, Colin wakes up and starts coming towards Rose. He pulls himself along the walls and somehow creates a horde of giant cockroaches with human faces, which chase Rose out the door and down the hallway. The bugs find the miners and take them down, and Rose runs faster. Unfortunately, while she's running, she gets blocked by a giant of a man with a pyramid helmet for a head. He swings his massive knife at her (it's about ten feet long and two feet wide) and runs, crossing some in-school bridge. He catches up and knocks her out a window, and she falls two stories to the ground. She runs to the other side of school, into another wing, and eventually collapses by a bank of lockers.
We then cut to Chris, who is apparently searching the school with Detective Gucci in broad daylight, and it looks just fine. Gucci tries to placate him a little, but Chris isn't having any of it. Suddenly, they pass the locker bank where on the other side Rose is lying in a heap, and Chris swears to Gucci that he can feel her and smell her perfume, though Gucci just ignores this and keeps Chris moving.
Meanwhile, Rose is still crying when we see someone come up and start dragging her somewhere. Eventually Rose ends up in a boiler room where we see that her abductor is... Cybill! She takes off the cuffs just in time for the bugs to show up again. They slam the door shut and lock it with a steel pipe through the handles when suddenly a giant knife slams through the door, narrowly missing them. The Pyramid Head demon tries a few more times and then starts trying to pull the door apart. Cybill shoots him a few more times but runs out of ammo just in time for things to revert back to normal.
Once the town returns to the regular side, Cybill puts her last clip in her gun while Rose tells her about the hotel key. The two make their way there as we see Chris finding out that there are no records regarding what happened in Silent Hill or at the very least, the records are kept private and locked up.
Meanwhile, we see Rose and Cybill get to the Grand Hotel. Inside, they see Dahlia being...plastered (guess they're out of stones)... by a woman named Anna (Tanya Allen). She chases Dahlia out and begins spouting some religious nonsense to Cybill and Rose. Cybill looks around while Rose asks Anna about Sharon. Anna points out a drawing on the floor of a cross with circles on the ends, and says it is a symbol of their faith that was created by the elders of their elders. They are interrupted by Cybill, who has found a bunch of keys scattered across the floor and a piece of art she found in the mailbox for room 111 that looks like Sharon's other works. Rose immediately decides that they need to find room 111 as soon as possible.
Back with Chris, we see that night has fallen on his side. He is outside the Braham's town archives. They lock up and leave the building. He heads over there and breaks in. He heads upstairs and after searching around a bit, finds the files for Silent Hill, including a report of a burning victim named Alessa Gillespie. Chris finds a photo of Alessa, and is shocked to see that Alessa looks exactly like Sharon. He dials a number on his cell phone and gets an address for a building.
Back with Rose, we see her, Cybill, and Anna -- who is apparently along for info -- looking for room 111, which apparently doesn't exist. Anna points out a picture of the first witch burning the town ever had, and Rose realizes the whole town was founded by witch hunters. In a flash of inspiration, she picks up a knife she took from the kitchen downstairs and tears the picture apart to find...room 111. They go inside and find that the room is little more than a storage closet with a hole in one wall that leads to another hole in the next building, and more beyond. Cybill jumps first, followed by Rose (who loses the knife), and they leave Anna to make the jump herself. Inside this new building they find more stuff and while Cybill is looking around, Rose catches another glimpse of Alessa/Sharon. She gives chase and eventually finds her crying on the other side of a huge pit that leads down into the mines, where we see fires burning. She jumps across, balancing on a few support beams and almost falling once. She goes up to Alessa/Sharon, and the girl turns around and says, "I'm burning" as her arms and then her whole body burst into flame. Rose screams and steps back, only to realize that Alessa/Sharon isn't there. Cybill and Anna find her and get her back over to them just as the siren starts up. Anna screams "The darkness is coming!" and runs off, with Cybill and Rose following close. They wind up at the town church, which is apparently the location of the siren. People are coming out of everywhere to get there while Dahlia stands in front, saying "You run not towards sanctuary but from your fears. Join not the others, for they are deceived as they are damned." Cybill tries to convince her to come inside, but she grabs Cybill and says, "No! They are wolves in the skin of sheep. They brought about their own hell. They'll take you with them!" Anna starts throwing stuff at her and screams "Filth and lies!" at Dahlia, but Cybill holds her back. Rose tries to talk to Dahlia about why they were brought here and what Alessa wants, but Dahlia's only response is, "Evil waits in vengeance. Be careful what you choose," as...
Just then the darkness comes. Things begin melting, and Cybill and Rose run inside as Dahlia points her index and ring fingers at Anna. She turns and we see that Pyramid Head has appeared behind her. He picks her up and rips her skin off, splattering Rose and Cybill with her blood. The door finally closes and people begin attacking Rose for being a witch until Cybill fires her gun in the air to calm them...or at least to get them away. The leader of the church, Christabella (Alice Krige) comes forth and reassures them that what happened to Anna was not the fault of "these outsiders." She then gathers the faithful in prayer for sanctuary from the darkness, declaring that "those whose names are not written in the book of life shall burn in the lake of fire."
Meanwhile, we see Chris inside the Toluca County Orphanage, trying to get information on Sharon's past. He tries to talk with one of the nuns running the place, but she is very resistant to the idea of giving out information, particularly hers. Chris starts getting rough when suddenly Gucci shows up again. He arrests Chris for breaking and entering (the archives), and then has a talk with him about justice, saying that it's a foggy concept, since there's man's justice, God's...and even the Devil's. He also shows Chris his hands, which were apparently badly burned by something sometime in the past. Gucci then informs Chris that he is being taken out of town and back to his home state and not to ever return again.
Back in Silent Hill, we see Christabella explaining to Rose that she will need faith to find her daughter and survive here, since, as she observes, "In the eyes of a child, a mother is God," but Rose isn't buying into this -- she just wants to find Sharon. Christabella agrees to take her to the home of the demon, and, with a few miners along for protection, they head to Brookhaven Hospital. Here Christabella informs Rose and Cybill that the demon is housed in room B151 and gives them a flashlight to see by, even though the monsters will be drawn to it. Rose memorizes the map as much as she can while two miners break open an elevator leading to the wards. Christabella moves to give back Rose's locket, which one of the faithful apparently took from her (Christabella's excuse: "We're scavengers.") when she notices the picture of Sharon inside. She starts calling Rose a witch and Rose runs into the elevator, with Cybill covering her. Cybill kills a miner with his own weapon and starts the elevator going down. Rose screams for her, but it's no use. Cybill trains her gun on Christabella and pulls the trigger...on an empty chamber. The remaining miners beat her senseless as Christabella smiles.
Meanwhile, Rose has descended about 40 floors a minute and is now getting out of the elevator. She finds herself in the A Ward, meaning she has to go down one more floor. She begins picking her way through but once on the B floor finds her way blocked by a bunch of freaky looking nurses bent in various awkward positions and holding sharp knives that could slice open an elephant. She shines the light on them and they all snap to attention and begin coming for her. She turns the light off and they go back to rest. She begins to pick her way through, but the nurses eventually wake up and start trying to attack her. She ducks down and tricks them into attacking each other. While they're busy with that, she gets free of the crowd, drops the flashlight, runs, and finds the room. She opens the door and...
We hear the voice of Alessa saying that she is going to show Rose the truth about what happened, as a reward for coming all this way. We see Alessa being picked on again, and she runs into the bathroom, which is being cleaned by Colin. He smiles at her and Alessa narrates about how desperate for love and acceptance constant hate can make you, and it is strongly suggested that Colin raped her. We later see her coming out of the bathroom and being talked to by her mother, who looked much better then, and her aunt/principal, Christabella! Since the town is so taken with Christabella, a town meeting is held, and it is decided that the sin shall be cleansed, and that sin is Alessa, since her mother does not know or will not reveal who Alessa's father was. Against Dahlia's protests, they tie her up and roast her over a fire, but the fire spreads until it consumes everything. We next see Alessa, blackened and crispy, being pulled from the wreckage as Dahlia weeps. Alessa describes how her hate grew so much, and how one day something gave her power to use that hate. One day, we see a young nurse doing her rounds. Lisa pokes her head into Alessa's room and becomes her first victim, and...
We see Rose in room B151. In front of her is what remains of Alessa (Lorry Ayers), who is now about 30 years older. She is being tended to by an eyeless and blood-covered Lisa. Lisa moves to sit next to Alessa, and then the little girl steps forward. Rose asks who she is, and we get a typical "I have many names" answer. She says that Sharon was the last representation of the goodness in Alessa, and that Sharon is about to be found by Christabella and her minions. Rose asks why she is here and "Alessa" says that it is so Christabella can be confronted with the truth. She then hugs Rose and proceeds to absorb into her body. While doing this, we see Sharon hiding in the Nathan Motel, which Rose kept passing throughout the movie, in time for Dahlia and a bunch of miners to come in. Dahlia tries to ward off the miners, but is unsuccessful and they take Sharon. Meanwhile, we see Chris being dropped off at his car in the early morning. Gucci says that they will keep trying to find Rose and Sharon, but Chris doesn't believe him and drives off.
We then cut to the church in daylight. We see a still-alive Cybill tied to a ladder while Christabella says that she must be burned. Cybill tries to shout some sense into the people, but is unsuccessful as one might expect. They lower the ladder over a fire as Cybill catches Sharon's eye and shouts that Rose is coming, but this just draws some laughter from the crowd, who then proceed to burn Cybill's flesh off. The crowd then gets set to burn Sharon too when the doors slam open and we see Rose standing there, with Dahlia creeping up behind. Rose -- now covered in blood, wearing all red, and with fire in her eyes -- begins taking the townsfolk to task for what they are doing, but Christabella orders her burnt as well. Rose laughs at this solve-all solution and gets right up in Christabella's face, but gets stabbed through the heart with a sacred knife of Christabella's. She calls Rose a blasphemer while Sharon screams...just as a drop of black blood falls from the knife to the floor of the church. Things grow dark, and Rose begins coughing out more and more black blood from inside. The blood spreads and the darkness at last overwhelms the church. Old Alessa rises out of the hole that was formed and begins running everyone through with barbed wire and killing them spectacularly while Rose heals (a gift of Alessa's) and makes for Sharon. She gets there with Alessa dispatching anyone who gets in the way while Dahlia watches in horror and asks her daughter, "What have you become?"
The young Alessa has shown up just in time for Christabella to get run through with barbed wire. She is torn apart by the wire from inside while Young Alessa dances in the blood rain just as Rose frees Sharon. They crawl into the corner and attempt to ignore everything as Sharon climbs up the ladder. Rose keeps telling Sharon to pretend it's a bad dream just as Sharon opens one eye to find Alessa staring her right in the face.
The next morning, we see a depressed Chris arriving home, going inside, and closing the door.
Meanwhile, we see Rose and an eerily calm and happy Sharon walking out of the church. Dahlia asks Rose why Alessa didn't kill her and Rose repeats what Christabella told her about a mother's love; "Mother is God in the eyes of a child". Dahlia looks at the two, and Sharon looks at her, and it is strongly implied that Sharon is now Alessa.
Rose and her daughter head back to the car, and Rose calls home. The machine picks up, and Christopher hears only static, but we see Rose saying that they'll be home soon. Rose pulls out and through the fog, passes Cybill's motorcycle. They come to where the chasm was, but it fixes itself and they drive on through the fog.
They are still in a fog when they pass Braham's Gas and arrive home, where Christopher is sleeping through the unblocked sunlight. The girls go in, leaving the door open, and Sharon goes to play with something as Rose sits on a chair opposite the empty couch where Chris is still lying, having just woken up. He rises and lingers around the chair where Rose isn't sitting in his world, and then heads for the door. He sees that the door is open and runs forward, hoping to maybe catch a glimpse of Rose and Sharon, but when he looks outside, he sees only his car, parked right where Rose had parked her car.
Although Rose and Sharon are in the same room as Christopher, they cannot see each other, apparently because Rose and Sharon, still surrounded by fog, now exist in another reality or plane-of-existence, as a result of entering Silent Hill.