In the 15th year of the Republic of China (1927), the five oceans coexisted, and strange cases kept occurring on the Shanghai Bund as Chinese and Western cultures clash. Che Youyun, the former inspector of the Central Police Station of the Shanghai Concession, commits suicide. As a detective who came in with nepotism, Gu Yuan, together with Che Suwei, Che Youyun's righteous daughter, Kang Yichen, the deputy detective, and Cao Qingluo, a journalist, form a team of four to break the rumors of feudal superstition and solve a strange case from the perspective of social science and psychology. They witnessed the sorrow and happiness, love and hatred between people of different classes, together upholding the justice and fairness of the tenement, and dispelling the superstitious folk beliefs of strange powers. The team of four became loyal comrades who could trust their lives with knowing they got each others' backs. As they solve the cases, the four gradually approach the truth about the suicide of the previous inspector. With courage and trust between comrades, persistent pursuit of the truth, they defy the power to destroy the corruption of the upper echelons to prove the innocence of the former inspector Che You....