During the Anti-Japanese War, Hua Zhen, who was born into a family of high-ranking Kuomintang officials, originally wanted to join the navy to realize his dream of becoming a captain.However, an unexpected trip to Shanghai changed Hua Zhen's life completely - he changed his name to Xiang Yuansheng and became a low-level police officer in a dilapidated police station.Here, Xiang Yuansheng met the two most important people in his life, Chen Hao and Luo Minmin, who helped Xiang Yuansheng find the meaning of life.

Under the influence of Chen Hao, Luo Minmin and others, Xiang Yuansheng strengthened his communist belief, and eventually became an outstanding soldier on the party's hidden front, fulfilling his pursuit of ideals and beliefs.