The September 18th Incident broke out, and the Gu family, a border-guarding family, resisted the Japanese army and was brutally wiped out. Gu Xueying, the adopted daughter of the Gu family, survived and went to Qiqihar to find her fiancé Gu Zhaolong. Gu Zhaolong went undercover to become a puppet Manchukuo officer. Gu Xueying thought he had betrayed his country and was determined to kill Gu Zhaolong to maintain the family rules. Gu Xueying went to Qianshan to join the Anti-Japanese Volunteer Army and participated in the Volunteer Army's three attacks on Harbin. Later, the Volunteer Army was reorganized into the Northeast Anti-Japanese United Army under the leadership of the Communist Party, and it really exerted its combat effectiveness. Gu Xueying discovered that the Gu family's loyalty and righteousness coincided with the discipline of the Communist Party. She met Gu Zhaolong several times on the battlefield, but she was never able to kill him. In the battles, Gu Xueying and the staff officer Shen Leizhi gradually fell in love. Shen Leizhi was arrested in Xinjing, and Gu Xueying sneaked in to rescue him and found that her opponent was Gu Zhaolong again. As the Anti-Japanese War draws to a close, Gu Zhengxue, who has learned the truth, is assigned to the teaching brigade and together with Gu Zhaolong, he captures the Dongning Fortress. However, Gu Zhaolong...