"From the moment I entered Chang'an, I was full of lies and deception. I survived in lies, and deception can make me gain sympathy. I hate myself like this, but this is my mission..." - Gu Yue. In an accident, I forced my grandfather into a desperate situation, and I also went astray out of curiosity, becoming a sharp blade in the hands of Yizhi, the lonely lord of the desert... In the sixth year of Yuan Shuo, the Han army led by Wei Qing attacked the Huns in Monan, and the Huns were defeated. After three years of careful cultivation, the craftsmen were finally sent to Chang'an to embark on their true journey of craftsmanship. The mystery of life experience, informants in Chang'an, mysterious fellow travelers, Chang'an City seems to be hiding a huge secret waiting for me to uncover... [Actually, this is a novel I wrote in 12 years, but I didn't finish half of it at the time. I had nothing to do this summer, so I took it out and revised it, and continued writing. The last chapter of Sun Tzu's Art of War is the "Yongjian Chapter", so I thought that the war between the Han Dynasty and the Xiongnu might also use fine craftsmanship, so I wrote it based on this idea.