The Orphanage - J.A. Bayona

Laura, a former orphan, raises her adopted son Simón together with her husband Carlos in an old house and former orphanage where she was raised. While at the orphanage Simón tells Laura that he has five invisible friends which she believes are a product of his active imagination. Laura decides to reopen the orphanage to cater for disabled children and throws a party. During the party Simón tries to persuade Laura to go and take a look at his friends cabin but she's too busy. Later on she sees a mysterious masked boy and realizes that Simón has also disappeared. Laura feels the presence of other people in the house and months later Laura invites a team of parapsychologists to try to unravel the mystery.