The switch demon returns to the scene of the crime, and everyone is terrified of him. The police have found no weapon at the crime scene, but there is a cut on the victim's throat, which is about 2-3 inches long. It is not clear who killed the victim, but the police speculate that it is someone named "Qimu" , who was at the school at the time of the murder. When the police arrive, they find a carving knife in the trash can where the victim was killed