When modern historian Zhao Heng was researching the Song and Liao wars in the library, he accidentally discovered a mysterious ancient book called "Tiangong Kaiwu". After touching it, his eyesight went dark.
- Woke up and found that he was dressed in Chinese clothes and was in the bustling market of Tokyo in the Northern Song Dynasty. People around him called him "Nine Princes"
- After being shocked, Zhao Heng relied on historical knowledge to recognize that this was the Qingli period of Renzong in the Northern Song Dynasty, and he traveled through time and became Zhao Heng, the great-grandson of Song Taizong and Renzong's cousin.
