In big cities, new types of brain-computer interfaces are quietly becoming popular. "Brain hole" technology allows some people to customize their dreams, simulate reality, and read memories. It was originally promoted to improve mental health, but a series of surreal cases occurred - some people were addicted to virtuality and could not extricate themselves, some were misled away from reality, and there were even bizarre murders and "impossible escape" dilemmas. The protagonist Duan Xinglan (a neuroscientist) and the criminal policeman Xu Yuchen become connected because of the investigation of the "consciousness misdirection homicide case", and they are surrounded by AI scientist Han Youlan, self-media person Lin Yuanzhou, psychiatrist Ran Zilan, and hacker Zhao Chuqi. As they solved a series of urban strange cases, they gradually got closer to "the truth about human nature behind brain-hole technology" and uncovered a big mystery about society's collective memory, power struggle, and human beings' desire for truth. Everyone is forced to face their own hidden desires and fears. In the end, everyone's fate intersects at the boundary between reality and reality - the entire city is reaching the unknown limit of the brain.
