El orfanato

Laura grew up in an orphanage on the Spanish coast. Now an adult, she returns with her husband Carlos and their young adopted son Simón, planning to reopen it as a home for disabled children. The house is vast and weathered, beautiful in a decaying way. Simón begins playing games with invisible friends — a masked child named Tomás among them — that Laura takes for imagination.

A woman named Benigna arrives presenting herself as a social worker. While Laura is distracted, Benigna reveals something to Simón: that he is adopted, that there are files about him, that he is HIV positive. Simón confronts Laura with what he's learned. The conversation is left unresolved. That afternoon, during a party to mark the reopening, Simón disappears.

The police find nothing. Months pass. Carlos wants to accept that Simón is gone. Laura refuses to leave the house, convinced he is still there — that the ghost children are hiding him, or know where he is. She brings in a medium named Aurora, who makes contact with something inside the walls. The séance ends violently.

Laura researches the orphanage's history and finds the truth about Tomás: a deformed, masked child who was bullied by the other children. They lured him to the clifftop. He fell and drowned. His body was never recovered. His mother was Benigna — who later poisoned the remaining children and killed herself. The invisible friends were all real, all dead.

The ghost children have been leaving Laura a trail. She follows it — a treasure hunt game Simón had been playing, the same one they used to play. The clues lead her through the house to a locked room in an outbuilding she had never properly searched. She breaks through.

Simón had fallen through a trapdoor into a sealed underground room. He had been there since the afternoon he vanished — just meters from where Laura had been living, searching, waiting. He had the key to get out but couldn't reach the lock. He died in the dark alone.

Laura cannot survive what she has found. She takes sleeping pills and lies down in the old part of the house, in the room where the children used to sleep. She calls to them. They come — Simón, and Tomás, and all the others. She dies and becomes what she always intended to be: their caretaker. Carlos finds her body. In the final moment, he glimpses the children gathered around her, and understands.