In the early years of the Republic of China, the situation in Jiangzhou in the southwest region was chaotic, which led to frequent spies. Qin Huo Le, who returned from studying abroad, met the detective captain Song He and worked together to explore the secrets. With the help of female forensic doctor Fan Xiao Fan, the three of them used their sincerity and wisdom to clear the bloody fog that shrouded the people and protect justice in the world.