Sent to a Marriage Alliance, Crowned in the Enemy State

A prince of Daqian, Zhang Xuan, is framed by his brothers and forced into exile to Northern Liang for a political marriage. Ambushed on the way, he is saved by Qin Yunshu, a Northern Liang princess rumored to be simple-minded. The two strike a pact: he will help her seize the throne, and she will help him seek revenge back in his homeland. Against the repeated attempts on their lives by the Prince of Jing of Northern Liang, Zhang Xuan breaks through with medicine and strategy, and he and Qin Yunshu turn their sham alliance into a real marriage. He reforms abuses and wins over the people; she lays plans in secret and consolidates power. When the Prince of Jing kills the ruler and usurps the throne, the two counterattack together. Zhang Xuan turns the conflict between the two states to their advantage and ultimately helps Qin Yunshu take the throne as emperor, then leads an army south to retake Daqian. Two rulers stand side by side, the two states become one, and together they build an era of peace.