Empress Zhao Ling of Zhao Ling and Emperor Xiao Che of Dayan had old family grievances, but due to the world situation, they entered into a "Two Emperors Co-Government" alliance. One uses the "account book" as a blade to rectify internal affairs; the other uses military power as a shield to guard the borders. They are each other's strongest backing and fiercest rivals. They work step by step to check and balance each other in the court, but in private they are repeatedly pulled apart by old hatreds and emotions, performing the ultimate "love and kill each other".
At the same time, Chu Feng, Dayan's former general in the north, returned to the north in pursuit of the barbarian princess Agula and got involved in the dispute. Agula's brother, Xie Lin, the prince of the Man Kingdom, and his wife, Xiao Che's sister Xiao Yunyun, are struggling to survive in the civil strife.
When the war breaks out in the north, three lines of fate are intertwined. The alliance between Zhao Ling and Xiao Che became stronger in the test of life and death, and the entanglements between grievances and grudges were gradually melted away by affection. In the end, everyone set order with the ledger, protected the mountains and rivers with friendship, and jointly composed a long song of prosperous times in which the Central Plains and the grasslands coexisted.
