During the prosperous Tang Dynasty, Chang'an was prosperous. Thirty years after Wu Zetian proclaimed herself emperor, undercurrents in the government were surging, demons were rampant, and strange crimes occurred frequently.
Tianxing Division - a secret government office established by the imperial court, specializing in handling strange cases of monsters and ghosts, investigating cases openly and eliminating monsters secretly. Si Zhengxiang Tianxing, nicknamed "Black Yama" by others, has a cold face and a warm heart, and handles cases like a god. He holds the "Evil Killing Order" given by the late emperor, and can kill first and then report. He takes the widow Luo Xinqiu, the monk Xuanzhen who has returned to secular life, the fox fairy courtesan Qiu Qian, the thousand-year-old flower demon Hua Qiniang, the ghost market assassin Black Crow, the butterfly spirit Bai Xiaomo, and the powerful mute concierge Shi Gandang. In this ghostly river and lake, he starts a series of thrilling contests with evil spirits and court traitors.
From the ghost market buying people's lives, to the painted-skinned lady peeling off his skin and changing his face; from the cannibal flower in Baihua Pavilion, to the female ghost asking for life in the red gauze tent; from borrowing Yangshou from the paper shop, to the headless monk in Ci'en Temple; from the ghosts ringing the death knell at night, to the night walk of hundreds of ghosts in Chang'an City... Behind every strange case, there is a bigger conspiracy.
What Xiang Tianxing is tracking down is not only the demons causing trouble, but also his own confusing life experience. His father, Xiang Shouzhong, was involved in the Luoshui silver robbery case thirty years ago and was ruined. After his death, he fell into the animal realm and was reborn as a black pig. The real mastermind behind the scenes - Faceless Lord, an aggregation of ideas condensed by resentment and Yin Qi, began planning thirty years ago in order to use Xiang Tianxing's "Destiny of the Lonely Star" to open the passage between Yin and Yang on July 15th when the gate of ghosts opens, allowing the King of Netherworld to come to the world.
