Plot: During the Anti-Japanese War, Yun Hongshen unknowingly chases after his father's killer, only to fall into a trap set by "Black Butler," a Japanese spy who had been undercover in China for 15 years. With the help of a close family friend and guidance from the Communist Party, Yun Hongshen joins forces with patriotic youth Wen Yeming to expose the spies hidden within the Nationalist army