In parallel time and space, at the end of the Tang Dynasty, the separatism of vassal towns intensified, but a mysterious organization called "Tiance Mansion" appeared (it existed in the early Tang Dynasty in history, and it was strengthened here), aiming to continue Tang Zuo or create a new sky. The Khitan (Liao Dynasty) in the north is watching with eager eyes, and there are also changes in the Western Regions and Nanzhao. The protagonist Li Xuan, whose identity is (or suspected to be) a distant branch of the Tang Dynasty, is accidentally involved in world disputes.
