In the Shanghai Concession in 1941, undercurrents were surging. Shen Yanzhi appeared to be the manager of a foreign bank, but in fact he was an intelligence courier for the underground party organization, codenamed "Dengying". Relying on his precise judgment and smooth way of dealing with the world, he dealt with the Japanese army, the Wang Puppet regime and the military commander, and repeatedly sent key intelligence out of danger. During a mission, his partner was accidentally exposed. Before he died, he handed Shen Yanzhi a cufflink containing information and asked him to pass it on to the organization. After that, Shen Yanzhi was closely monitored by the Japanese army, and it was difficult to tell the truth from the people around him. Even the identity of his secretary Su Wan, who he got along with day and night, had a hidden identity. He shuttled through the dark alleys, playing games under the shadow of the lights, not only to avoid being chased, but also to identify the insider. In the end, with his extraordinary courage and tacit cooperation, he successfully delivered the information and protected the safety of the organization with his life.
