Action of movie (from wikipedia)
Laura, with her physician husband Carlos, returns to an orphanage where she had lived as a child with plans of reopening it as a home for sick and disabled children. They adopted a son named Simón who is HIV-positive, though he is unaware of either his adoption or his illness. Simón has imaginary friends and his mother is concerned that he is too old for them. He is scared in his large, dark new home and Laura tells him that the invisible light from the lighthouse at the beach will protect him.
Laura takes Simón to visit a cave near the beach, and he claims to meet a new imaginary friend there. After returning home, Simón draws a picture of his new friend. He is named Tomás, and he wears a sack mask. Because Simón has always had imaginary friends, both Laura and Carlos play along with his stories. Simón later says that he has become acquainted with six imaginary friends.
Simón is reading the story of Peter Pan. He asks Laura about Peter Pan and why Wendy couldn't go back to Neverland when she grew up, and he makes the comment that he will not grow up either, just like Peter and like his imaginary friends.
A mysterious social worker appears one day, talking obliquely of some new treatment for Simón and revealing to Laura that she has his old adoption file. Laura becomes angry at her intrusion with these hidden truths and sends her away, locking Simón's file in a desk in the kitchen. That night, after investigating some rattling noises she hears outside, Laura finds the mysterious social worker hiding in a shed. Though Laura screams for Carlos' help, the woman escapes before anything else occurs. After they report the incident, it is discovered that there is no social worker registered with the name Benigna, which the woman gave.
One day, Simón tells Laura about a game that Tomás has created for him, a type of scavenger hunt. The game begins when your treasure is taken and you find something in else in its place. To play, you take that object to its original place and find something else, and so on. Simón says that at the end they should find his treasure (gold coins) and that he will then get a wish. The coins are finally found in the locked drawer where Simón's file is hidden. Simón angrily reveals to Laura that he knows that she is not his real mother and that he is going to die. When she asks him how he knows that, he responds that his new friends told him.
Soon after, Laura hosts a party for the disabled children to welcome them to their new home. When she asks Simón to come down and join them, he first demands to show her where Tomás' "little house" is. After a brief argument, during which Laura angrily slaps Simón's face in the heat of anger, she leaves Simón alone upstairs. Back in the garden, she watches the children in play, all of them eerily wearing masks that Carlos is taking out of an old trunk. She and Carlos exchange looks as she nods upstairs, indicating that Simón is still in the house and she will bring him to the party. As she walks away, she does not notice a boy with a sack mask and a whistle necklace, who looks a lot like the picture that Simón drew after their visit to the cave. The name "Tomás" is embroidered into his shirt.
When Laura returns to check on Simón, she cannot find him. She looks in the bathroom at the end of the hall, only to be confronted by the boy in a sack mask. When she tries to remove the boy's mask, he violently locks her in the bathroom, slamming the door on her fingers and pushing her back into the tub. She screams for Carlos and he pries the door open. She then starts a frantic search through the house and throughout the masked children, looking and calling for Simón. In her search for Simón, Laura runs out to the sea to check the cave and breaks her leg badly on the partly-submerged rocks. She sees a small boy standing in the cave, but she can't make it to the cave because of the high tide and her broken leg. The police search, but Simón cannot be found; he has simply disappeared without a trace. At the medical center Carlos brings the police psychologist Pilar in to speak with her. Pilar and Laura agree that Benigna may have abducted Simón, and Pilar assures her the police will find the woman.
Late in the night after returning from having her leg set, Laura hears banging and pounding in the walls of the home, which frightens her and begins to make her think something supernatural may be occurring.
Months later, Laura and her husband go for a drive. At a traffic light, they are surprised by Benigna crossing the street in front of them. Oddly, she is pushing a baby carriage. Laura calls out to her and as Benigna turns to look at them she is suddenly rammed by a speeding ambulance. Laura, in a panic, checks under the ambulance that ran over Benigna, thinking Simón might be in the carriage. Instead, she finds a doll with a sack mask that looks like Tomás. Laura then rushes to where a crowd has gathered around the stricken woman; Carlos is attempting to resuscitate her, but to no avail. Laura reaches for Benigna's whistle necklace and in her dying breath the woman snatches Laura's hand away.
After searching Benigna's home, the police find old super 8mm films and photographs, discovering that Benigna worked at the orphanage long ago. The police psychologist Pilar shows Laura an old photo with her in it and her five childhood friends. In the back row we see a young Benigna, whom Laura does not remember from the orphanage. It turns out that she had a deformed son named Tomás, whom she tried to keep hidden from everyone and who wore a sack mask to cover his deformed face. After Laura had been adopted and left the orphanage, her five remaining friends played a horrible trick on Tomás, taking him to the beachside cave and stealing his mask from him. They wanted to see if he would dare to come out without his mask on. Ashamed, Tomás refused and drowned in the cave once the tide rose.
The desperate Laura attends a lecture on the paranormal and then arranges to have a medium explore the orphanage for clues to her son's disappearance. During the exploration, the medium sees five child ghosts and hears them screaming in pain, dying of poisoning. The medium reveals to Laura that the reason she can see the dead is that she has been close to death herself, showing scars on her arm and looking at Laura's scars as well, and also suggesting that the reason Simon saw ghosts was his HIV disease. This upsets Carlos and, despite the fact that he heard the children's voices as well, he - with the support of the psychologist Pilar - kicks everyone out of the home, dismissing it all as parlour tricks. As the medium's team is leaving, Laura begs the medium to tell her how to find her son, and the medium replies that Laura must use her grief as strength to help find him, but it all depends on how far she wants to go. She says that the phrase "seeing is believing" should actually be the other way around - that by believing, one begins to see. Carlos thinks his wife has gone crazy and begs her to leave the orphanage, but she refuses.
Later Laura follows clues she believes are being left by Tomás in a scavenger hunt game again, leading to a doorknob. Though she does not find the door to which the knob goes, she does find five sacks full of partially-cremated human bones in the very shed where she caught Benigna snooping. The police come in and conclude that Benigna had exacted revenge on the children whom she felt had cruelly murdered her son. Carlos and Laura argue, and Carlos again asks her to leave with him, but she refuses; she insists that there are too many memories in the house and that she needs two days alone to say good-bye before joining him.
After recreating her time in the house as a young girl by bringing in the old furniture and linens and by dressing up in a matron's uniform, Laura takes her sedation medication to come close to death herself. She conjures the ghosts of her dead friends from childhood by playing their favorite game, and they lead her to a hidden door in a closet. The doorknob from her earlier game opens the door. Behind the door are stairs leading to a dark basement room where she finds Tomás' drawings of the other children all over the walls. She then finds Simón alive and hugs him to her in a blanket, frantically urging him to pretend that this is all a fantasy, that his friends aren't real and to make them disappear. However, when the ghosts go away, she realises the blanket is empty and it slips to the floor. She then notices a body on the floor with Tomás' sack mask on. After unmasking the boy it turns out to be Simón, who is dead. In a sickening revelation, Laura realises that the day Simón went missing, in her frantic search for him, she'd unintentionally prevented his escape from the basement: she had accidentally blocked the hidden door with metal poles stored in the closet, which Simón had pushed away to gain access to Tomás' "little house," the place where he went after their fight when she slapped him. The banging and pounding Laura heard in the walls earlier in the movie was actually Simón, and the subsequent crash was the sound of the him breaking and falling through the fragile stair banister to the floor below, killing him.
Laura carries Simón's body up to the dormitory, sits in the window seat and proceeds to swallow all her medication, begging aloud to be able to be with Simón again. Though she doesn't realize it, she has just made the wish granted once you find your treasure (for her, Simon) in the scavenger hunt game. As her eyes grow heavy, she sees that the lighthouse has been lit once again and is shining into the room, revealing the ghosts of the six dead children, including Tomás. Simón, who is now alive in her arms, makes his wish for finding his coins when he was alive: that she will stay and take care of him and his friends forever. They look up and see all her old friends and Tomas with them in the bedroom. They approach her, and laugh that she has grown old like Wendy, and she snuggles with them and begins to tell them a story. The implication is that she also has died and gone to the "never-never-land" of the lost children; one of the ghost children remarks that Laura is like Wendy grown up. In the end Carlos walks over a gravestone of his wife and Simón who had died. He returns to the house for one last time. In the orphans' old bedroom, now empty, he finds the lucky necklace that Laura said she will return once she finds Simón. The doors to the bedroom open in a ghostly way for him, and he smiles.
[MJ]
