Lin Nan traveled through time and became a "quiet" patient in Qingshan Mental Hospital. He thought his life consisted of eating, sleeping, taking medicine, and bragging with a group of interesting lunatic patients. Until a "theater ghost" serial murder case shocked the city and the police were helpless. The newly appointed beauty director Qin Shuang found the only hope in a dusty top-secret file - a legendary criminal investigation expert codenamed "Judge". When Qin Shuang opened the door of the mental hospital, he discovered that the legend who could see through people's hearts was Lin Nan, who was holding a cat and muttering to himself that the cat told him who the murderer was! The entire police station thought he was a madman, but Qin Shuang was completely shocked after witnessing Lin Nan accurately predicting the location of the next crime with crazy words!
