Shen Yuan, the daughter of a salt merchant, secretly controls two major trading houses. For five years, she has anonymously supported her childhood sweetheart, Pei Huaijin, helping him become the General Who Guards the North. On the eve of their wedding, the Grand Princess Zhaoyang forces her way into the marriage. The Emperor decrees that Pei Huaijin shall marry the princess and orders Shen Yuan to be sent away in a political marriage to a foreign tribe. Pei Huaijin gives in, and Shen Yuan drinks poisoned wine before climbing into a coffin. Sensing something amiss, Prince Zhao Jingheng, the Eighth Prince, opens the coffin and saves her life. Shen Yuan rebuilds her trading houses and, during the war in the northern frontier, escorts provisions and breaks through enemy formations, saving tens of thousands of soldiers. She also exposes the Grand Princess's treasonous dealings with the enemy. The Grand Princess is executed, and Shen Yuan marries Zhao Jingheng. Pei Huaijin sacrifices his life to save Shen Yuan. She finishes embroidering half a gardenia on a handkerchief and places it in his coffin, finally putting their past to rest.