Silent Vows

In summer 1937, as Japanese forces conduct maneuvers along the riverbank, Chen Ming, posing as a mail carrier, pursues Mei Xiang and becomes entangled in the 'Kill Their Horse' incident. Before his father Cheng Zhen Shan is assassinated, he entrusts the plan to Cheng Yu, ordering him to wait for a contact. Chen Ming discovers Mei Xiang is actually a Japanese spy. After the core character Qiao Jun Sheng sacrifices himself, Chen Ming teams up with driver A Chang and undercover police officer Yan Ruonan to decrypt encrypted text from a music box. Mei Xiang sets fire to force the plan's execution but is killed by Chen Ming. Yan Ruonan's identity is revealed as Jun Sheng's wife's younger sister. Chen Ming joins the anti-Japanese resistance organization and separates from Yan Ruonan due to mission requirements. Finally, the 'Kill Their Horse' plan is restarted, and everyone rushes to the front lines.