At the end of the Southern Song Dynasty, the Sword Forging Valley in Longquan, Zhejiang was captured, and the three young protagonists, the Zhuang sisters and Hu Lizhi, were displaced. The three supported him to go north, looking for a person with firm will and dedication to inherit the art of "Sword Forging" and carry forward the declining art of sword making. In the midst of the chaos, he had to avoid being tracked by the Mongols and beware of the covetousness of the Jianghu people. He accidentally got involved in the treacherous palace battles, dealing with Zhengming Tower and Wuyi Lane. And friendship and love are so pure, giving them great courage.