To save the people and the Tang Dynasty from the disaster in Chang’an City. The queen ordered Di Renji to resolve the matter in cooperation with Liu Yi. After many difficulties, Di Renji finally found the key clues in the case, and the source pointed directly to the two princes Xun and Song Yi. And is the main suspect behind this whole incident really Song Yi? Di Renji had an answer, but he decided to bury it in his heart.