In 2008, an inexplicable disappearance of students occurred at Hanjiang High School in S City. A total of five students were involved in the incident. Four of them disappeared and returned to the place of disappearance 5 hours later. The remaining one has not returned yet. Two months later, the police investigation has still yielded no results. City S, together with the police school, permanently sealed the case on September 11. The school was demolished a year later. Eight years have passed, but one person is missing and his whereabouts are unknown...