In 1943, during the Japanese occupation of Shanghai, an explosion targeting the Japanese agency shocked Shanghai. Lin Shaobai, a shrewd concession policeman, and Lu Zhengyang, a resolute and resolute red agent, faced off for the first time. Each showed their skills and also...It completely changed the fate and life trajectory of the two people.

Six years later, Shanghai was liberated.Lin Shaobai and Lu Zhengyang met again. One was an old police officer who was imaginative and clever, and the other was a new police officer who was upright and straightforward.Facing the severe anti-special situation, Lu Zhengyang had to join forces with Lin Shaobai, known as "Shanghai Know-It-All". The two did not trust each other but had to cooperate. They formed a partnership in the second room of the Social Affairs Department of the Public Security Bureau and successively cracked the case.The "Vault Robbery Case“", "Financial Trend Case”", planned by Zheng Lanting, the ace agent of the Shanghai Special Station of the Secrecy Bureau,

A series of major cases such as the February 6 bombing case and the epidemic war completely defeated Zheng Lanting's painstaking plan to overturn the sea.

In the process of repeatedly solving major cases, Lin Shaobai kept coming up with clever ideas and was known as the “Shanghai Know-It-All”. He was good at digging for clues from three religions and nine streams. Lu Zhengyang controlled the overall situation, was proficient in special agents, and had extraordinary skills. The two gradually established a relationship from constant friction.Trust until we become comrades and comrades who share life and death.Under the influence of Lu Zhengyang, Lin Shaobai gradually regained his original intention as a police officer to "be the iron wall of this city", and eventually transformed from an old policeman into a glorious people's police officer.Under the influence of Lin Shaobai, Lu Zhengyang untied the knot that had been hidden for many years.

Standing against the darkness and guarding the light is not only the commitment of Lin Shaobai, Lu Zhengyang and others to the city of Shanghai, but also the glorious mission fulfilled by the first generation of public security officers in New China with their lives and blood.