Winter 1939, Shanghai occupied area. Xi Yunfan, who had just graduated from the special training class for military reunification, was urgently transferred to Nanjing under Japanese occupation and lurked as a down-and-out businessman. His mission was to approach the confidential secretary Zhou Fohai, the leader of the Wang Puppet Government's Secret Service Committee, and obtain the overall plan for the "May Offensive" that the Japanese army was about to launch in Chongqing. However, when he had just opened a breakthrough, the liaison officer of the Nanjing Station of the Military Command was suddenly arrested and rebelled, and the entire intelligence network was facing destruction. Xi Yunfan not only has to evade the pursuit of Japanese and puppet spies, but also has to identify the true position of everyone around him alone - his seemingly honest and honest boy is actually an observer planted by the underground party of the Chinese Communist Party; the inspector of the patrol room of the French Concession who favors him has actually been bribed by the Japanese military police. In the life and death tests, Xi Yunfan gradually understood that the real heroes are not necessarily at the forefront of the battlefield. Those who deliver information in silence and hold on to their beliefs in the darkness also write the backbone of the nation. He used his proficiency in radio and code-breaking to cleverly devise a method of transmitting intelligence using Bible chapter numbers, and finally sent precise information on the main mobilization of the Japanese army to Chongqing three days before the launch of the "May Offensive." But the price was that his identity was exposed and he was forced to launch a thrilling escape and counterattack in Nanjing.
