Xu Zhongliang's father was a postman, and he was also an underground party member. One day he was betrayed and assassinated by the Japanese. Xu Zhongliang wanted to avenge his father and embarked on the road of revolution since then. While serving as his father's professional postman, he also encountered dangers again and again and lost many of his colleagues. Zhou Shan was also a postman and an underground party member. The priest sympathized He also helped the revolution, but he also lost his life in the process. His first wife also died while he was working as a postman, but Xu Zhongliang did not bow to the evil forces. Su Lina, the Communist Party's informant, has worked together to complete a lot of important information transfers. Including in the battle of the liberation of Shanghai, Xu Zhongliang also delivered a lot of important information, but he was attacked by the enemy during the process of being a guide, was seriously injured, and almost lost his life. He trained himself to be a thorough revolutionist