There is a turbulent undercurrent of seizing the throne in the Dayong Dynasty. The third prince Xiao Che uses the golden finger's "preemptive mirror" to understand the crisis, but is put in danger because of the old case of his mother and concubine. Shen Lingxi, the elf daughter of the Duke of Zhen, accidentally broke into Xiao Che's plot and was forced to form an alliance with him. In the court, the powerful prime minister and his son covet the throne. There are secretly interfering eunuchs in the palace, and there is also betrayal and conspiracy between brothers. Xiao Che uses strategy as an edge and uses the "mirror of opportunity" to break the situation, while Shen Lingxi uses dexterity and dexterity to maneuver around all parties. When the unjust case of the mother and concubine left over from history comes to light, and when the old emperor becomes undecided in his twilight years as a hero, can this pair of enemies win the fateful showdown and decide the fate of the country?