In 1943, a shocking explosion in Shanghai resulted in a confrontation between Lu Zhengyang and the former police officer Lin Shaobai. Six years later, Shanghai is liberated. Lu Zhengyang and Lin Shaobai team up and successively solve major cases such as the "Treasury Robbery", completely thwarting the conspiracy. Working on cases together, Lu Zhengyang and Lin Shaobai go from constant friction to gradually building trust and eventually becoming comrades who live and die together.