Su Yingying (Xu Zhenzhen), the daughter of the loyal cabinet chief minister Su, was killed by Xie Yuheng (Zhu Minxin) on the day of her marriage to the second prince Xie Yuheng (Zhu Minxin), who claimed that Su had colluded with the enemy and committed treason. Xie Yuheng then ascended to the throne of the crown prince. Three years later, Su Yingying returned to seek justice for her father and investigated the case of treason. She teamed up with the seventh prince Xie Yian (Lin Zehui) and disguised herself as Su Ying, a maidservant beside Xie Yian. The two started with the fake silver bill case and found that the case was related to Su Shoufu and Xie Yuheng, so they conducted an in-depth investigation. The two of them went from being at odds with each other to falling in love with each other. They worked together and approached the people involved in the fake silver bill case regardless of danger, and got closer to the truth step by step. They also exposed Xie Yuheng's conspiracy to seize power and usurp the throne. It turned out that Xie Yuheng was not of royal blood. In order to fight for the royal power, he created fake silver bills to accumulate wealth, bribed officials and cultivated a killer organization "Suzaku Pavilion" to eliminate dissidents. Because Prime Minister Su found out that Xie Yuheng was the mastermind of the fake silver bill case during his lifetime, Xie Yuheng ordered people to steal Su Prime Minister's official seal and forge documents of Su Prime Minister's collusion with the enemy to frame Su Prime Minister.