Zhou Heng, a modern special forces instructor, accidentally traveled back to the sixth year of Xuanhe in the Northern Song Dynasty and became the commander of the Daizhou border army. Facing the upcoming Jingkang Incident, he used modern military knowledge to transform the ancient army and severely damaged the Jin Army's West Route Army in the Taiyuan Defense Battle. When news of the fall of Kaifeng came, Zhou Heng gathered his defeated troops and established the "Northern Xinjiang Army", uniting civilian martyrs to create a new military system. The development of firearms and the reform of the military system in the Taihang Mountain base area formed a strategic echo with famous generals such as Han Shizhong and Yue Fei. After experiencing the bloody battle of Zhending and the surprise attack on Yanjing, Zhou Heng gradually grew into a key figure in changing the direction of history, and built a steel defense line against the Jin army on the ruins of the Northern Song Dynasty.
