Xueyi is the youngest daughter of Empress Yunzhuang of the Dongzhao Dynasty. She was named Princess Qinghe when she was ten years old and moved to the fiefdom of Qinghe County. The female official Biyuan was responsible for teaching her all daily life and state affairs. Three years later, the queen passed away her eldest sister Shanmei in Xueyi, and then retired to the court with her two royal husbands.
She was originally a carefree head of a county, but suddenly she encountered a shocking change. Her eldest sister was killed, leaving the emperor's niece alone and helpless. She was under great pressure to succeed to the throne. However, three men suddenly appeared and promised to accompany her, and they were all men of the eldest sister. Who is the murderer of her eldest sister? What else is waiting for her behind the throne?