In a world where everyone must enter horror dungeons at the age of twenty, the young girl Nan Yue has been haunted by an evil ghost for twenty years, only to find that survival games can suppress it. Relying on her calm mind and extraordinary courage, she teams up with Gu Xiangkai and Zhu Xining to crack the rules, counter-kill evil ghosts, save companions, and gradually take control of the evil entity within her. Fighting all the way from Nameless City to Eden, she uncovers the cruel truth behind the Cleaner Project.