Laura grew up in an orphanage, where a group of children played the game "One, Two, Three, Look Back" every day, and they were very friendly. 30 years later, Laura, who had married and had a family, came to the long-abandoned orphanage on the coast again with her husband and son. In order to relive the warm memories of her childhood and help more orphans, they decided to rebuild it. However, Simon, the 7-year-old son, began to act strangely since he moved into the house. He imagined three non-existent children playing. Laura and her husband were worried about this adopted son who also had AIDS, and Laura's excessive worry disgusted her son. They didn't believe in the authenticity of those hallucinations until Simon disappeared one day. After a 9-month investigation, Laura began to believe in the existence of ghosts and found that the matter was related to a caregiver in her childhood. She calmed down and played games with these "children" in the hope of rescuing Simon.