In the early 1930s, Lin Siyun returned to China after completing her studies with the dream of opening a maternity hospital. As soon as she arrived in Shanghai, she faced a difficult situation: her father's death, her brother's debt, her fiancé's betrayal, and the gangster lawyer Cheng Ao came to collect the debt. In the face of numerous difficulties, Lin Siyun rose to the challenge and had just established a high-quality obstetrics and gynecology hospital when the Anti-Japanese War broke out. Facing national hatred and family feuds, Lin Siyun and Cheng Ao became fellow travelers of the Communists. Cheng Ao and Lin Siyun went from misunderstanding to becoming close comrades-in-arms, experiencing the bloody storm together, and working together to survive the dark era before the arrival of the new society.