In 1937, the Battle of Songhu broke out, and undercurrents surged on Shanghai Beach. Zhou Yanbai, a clerk who originally just wanted to make a living in the Shanghai District of Zhongtong, was forced to be involved in the bloody spy battlefield because he accidentally discovered the secret dealings of Japanese agents. He dealt with the power struggles among the top leaders of the Central Unification Committee, the viciousness of the Japanese military's special high school, and the secret contests of the underground party, wandering on the edge of life and death again and again. In the process, he met Su Wanqing, a thoughtful female agent of the Central Government, Shen Mansheng, a dancer who dares to love and hate, and Lu Mingwei, a mysterious underground party member. Faced with the righteousness of family and country and personal emotions, Zhou Yanbai gradually grew up from a submissive little person to a spy sea waver who could stir up troubles in the undercurrent, writing the legend of the Anti-Japanese War belonging to the little person in his own way.
