When Yunqi woke up, he found that the whole city had changed. Pedestrians on the street were walking in strange steps, repeating the same movements, and muttering the same words - "Don't look back." He lowered his head and saw a line of bloody words on his wrist: [Rule 1: Do not respond to anyone who asks you questions]. What's even more frightening is that he discovers that everyone around him is acting according to an invisible rule book, and he himself is the only "violator" in the city.
