At the turn of the Song and Yuan Dynasties, the world was in turmoil and the country was unstable. The grievances of the old dynasty are intertwined with the ambitions of the new dynasty, rituals and music are broken, and strange forces and chaos occur frequently. In order to stabilize the country, and at the same time to explore the strange secrets that threatened the imperial power, Emperor Yuan specially gave Lin Ran, a young official, the position of "Jiuzhou Patrol", which allowed him to travel around the world, investigate cases and redress grievances.
