Gu Yizhong, a son of the Gu family in Suzhou, returned to China after studying architecture at the University of Pennsylvania. After the outbreak of the Anti-Japanese War, he and his girlfriend Xiao Ruotong joined underground organizations.After a rescue operation failed, all contact points of Suzhou's underground organizations were exposed.Gu Yizhong was mistaken for a traitor within the party due to deliberate frame-up by the Japanese and puppets. Unable to prove his innocence, he took the initiative to infiltrate the Japanese and puppets. After many twists and turns, he finally became a latent agent of our party in the Suzhou secret service station.

Under tremendous pressure, Gu Yizhong will fight with Zhou Zhifei, the head of the Suzhou Wang Puppet Secret Service Station, and Toshio Kondo, the Japanese military adviser, and wait for the opportunity to find the real traitor in the party, Black Eight, and remove him.Gu Yizhong continued to secretly collect intelligence for our party, saved comrades in the party from danger many times, and provided tremendous support and help to the anti-Japanese and national salvation movement organized by our party's underground organization in Suzhou.He moved forward with unwavering faith and continued to grow in the struggle.