Under the prosperous appearance of Canglan City, two major gangs, the Red Flame Alliance and the Jackdaw Society, control the underground world, and the corrupt chain of the police force serves as their protective umbrella. Criminal police officer Yan Shen traces the crime and bears the blood feud between his parents. He transforms into a "Night Owl" and sneaks into the Red Flame Alliance. He relied on his magical "crime mirror deduction" skills to see through conspiracies time and time again, from underground casino bomb crises to transnational drug trade secrets. In the double stranglehold of gang suspicion and mole, he dealt with the young leader of the Red Flame Alliance, formed an alliance with the brain trust of the Jackdaw Society, and walked on the edge of life and death. When the well-designed trap finally uncovers the inner ghost, can Yan Shen single-handedly tear apart the criminal underworld of the two gangs and bring dawn to the city?
