Lu Tianming, a lame scholar who suffers from lung disease, activates the calligraphy system after traveling through time and practices Qi to heal his injuries by writing letters on behalf of others. The ruler at his waist hides the "Taiping" rapier left behind by his father. He was accidentally involved in a salt smuggling case and a border army food and salary conspiracy. In order to save his friend Liu Dabao and repay the kindness of the Yang family, he showed off his sword skills and defeated the evil forces of the inspection department and gangsters one after another. Later, they formed an alliance with Feng Erniang, Bei Feng and others to rescue Ji Qianyu, the widow of the former King of Liang, and exposed the business of "cairen" in Chuixuelou and the conspiracy of Wumi Kingdom. They went through hardships and dangers all the way north, and finally integrated the essence of the five elements to cure stubborn diseases, guarded the northern border with the sword of peace, and fulfilled their chivalrous mission.
