During the Qingli period of the Northern Song Dynasty, Xixia invaded the border, and undercurrents surged in the court. Zhao Minglan, the princess of Roujia, was involved in a dispute over the imperial sword and seal due to the mystery of her life experience, and was forced to join forces with the upright bodyguard Lu Zhao. From the palace to the rivers and lakes, the two swore an oath with swords to break the conspiracy and protect the country. When the sword's edge reflects the moon, is it the love between children or the destiny of the country and the common people?