On the streets of Chang'an, "New Questions on Arithmetic Studies" newly printed by the Institute of Arithmetic Studies floated, but the white flags in the mourning hall of the Wei Mansion were blown by the autumn wind. When his father Wei Zheng was critically ill, young Wei Mingyu returned with half of the imperial edict. She originally thought it was Cheng Huan's bed, but she saw a shocking secret on the blood-stained back of the paper - there was another secret behind the death of the Sui Emperor, and Li Tang's ascension to the throne was actually hidden in half of the edict.
From the dry well of the Sui Palace to the Yingzui Cliff of Zhongnan Mountain, from the Luoshui Bridge in Luoyang to the Turkic Langtou Peak, calculations and fire guns are intertwined into a web. During the pursuit of the Xuannio Guards, Wei Mingyu not only has to uncover his father's legacy of "arithmetic passed down to the world", but also piece together his mother's secret life experience as an embroiderer in the Sui Palace. The appearance of the twin aunts, the mystery of the true and false jade seals, the national password in the golden thread of the phoenix robe... Every step is like walking on thin ice.
When the national jade seal appeared at the bottom of Caohai Spring, and when the movable type printing plate of the Arithmetic Academy knocked the wind and snow in Mobei, the young man finally understood: What his father weaved was not a web of arithmetic, but a web of human hearts that allowed people in the world to distinguish right from wrong and truth from falsehood. The silver hairpin in his hand, the edict in his arms, and the bamboo pieces in his amulet bag have already linked up the century-old past from the Embroidery Tower of the Sui Palace to the Tai Chi Golden Palace.
This is not a simple pursuit of a murderer, but a counterattack by a poor student who uses arithmetic to break the situation; this is not an ordinary secret investigation, but an orthodox legend continued by two dynasties with their blood and wisdom. When Wei Mingyu walked into the Chang'an city gate with the jade seal, what awaited him was not only the emperor's reward, but also the last half of his mother's unfinished embroidery manuscript, which contained a thousand-year-old secret.
