In the third year of the Apocalypse, three bizarre murders occurred in Yingtian Mansion: the owner of the embroidery shop died in a secret room, holding half an embroidery needle tightly in his hand; the owner of the pawn shop fell in front of the cash cabinet, with wet cinnabar on his fingertips; the Mr. Bookshop leaned on the desk, with the tip of his pen poking between his eyebrows - the three corpses were all engraved with the same strange totem.
The frustrated deputy Qianhu Shen Yan of Jinyiwei was dumped by his boss to investigate the case because of his "treacherous words", but he accidentally bumped into Su Qinghuan, the youngest female officer of the Injury Examination Department. One is good at finding flaws from clues, and can choke people into silence when he complains about them; the other is proficient in autopsy and mechanism secrets, and can stay calm in trouble than men. The two went from being "enemies" who disliked each other to being forced to team up to investigate the case, only to discover that behind the murder was an old case that spanned ten years, and even involved the connection between Jianghu secret societies and palace artifacts.
As more victims appear, the totem carved on the corpse turns out to be the key to cracking the code. Shen Yan's embroidered spring knife can cut off the bright and dark arrows, but it cannot unravel the ghosts in people's hearts; Su Qinghuan's autopsy knife can distinguish fatal wounds, but cannot understand the entanglement of love. When the truth gradually emerged, they discovered that the most terrifying thing was not the murderer's conspiracy, but the human heart hidden under the mask of "justice."
