In the spring of 1937, a small group of Japanese troops was stationed in Fuwang Town in the Japanese-occupied area of ​​Central China. On the surface, they are controlling the Chinese civilians, but in fact strictly guarding the safety of a secret underground arms depot, warehouse 103, waiting for the arms support response from their larger army. After the Communist Army learned about this, they sent an intelligence agent to sneak into the Japanese army in Fuwang Town to explore the information of Warehouse 103.