Li Kuan, a modern history enthusiast, accidentally traveled through time and possessed the body of Li Kuan, King of Chu, the second son of King Qin Li Shimin of the Tang Dynasty who died young and had very little written history. What he carries is not only a modern soul, but also a "fatal secret" from the future about the rise and fall of the entire Tang Dynasty. He knew that his father, Li Shimin, would kill his brother in Xuanwumen in the ninth year of Wude, force his father to abdicate, and start the Zhenguan rule; he also knew that the original owner of his body would die prematurely of illness soon, becoming a regret mentioned in history books. Once this secret is exposed, he will be regarded as a monster and will never be saved.
