During the Anti-Japanese War, Jiangcheng, an enemy-occupied area, was tightly controlled by the Japanese army, and underground work was on thin ice. Shen Yan lurked as a clerk in the Japanese military intelligence department. With his photographic memory and code-breaking ability, he traveled on the edge of life and death many times to collect key intelligence on Japanese military deployment and material transportation. After patriotic student Su Wan joined the underground organization, he became his intelligence liaison. The two cooperated tacitly to pass on intelligence under strict surveillance. Japanese intelligence chief Kenichi Matsui was suspicious of Shen Yan and set up traps to test him. Shen Yan saved the day several times. In the end, the two worked together to complete the key task of "attacking the Japanese arsenal", providing important support for the victory of the frontline war of resistance, and using faith and courage to ignite the fire of hope behind enemy lines.
