The severed hand takes Wei Wuxian and Lan Wangji to Yi City, a coffin-making town surrounded by a deadly miasma and even deadlier zombies. They run into Jin Ling, who got separated from Lan Sizhui & Lan Jingyi. Lan Wangji tells the story of Xue Yang, who murdered the entire Cheng clan. Xiao Xingchen and his cultivation partner, Song Lan, argued for his death and Nie Mingjue was more than happy to oblige, but Jin Guangshan objected and kept him alive. Xue Yang escaped, poisoned and blinded Song Lan and Xiao Xingchen blinded himself after finding his partner injured.In the current timeline, Xiao Xingchen shows up in Yi City and starts attacking the undead.