Young Liu Hengshun admires Duan Lin, the head of the town's security bureau in Jiuhe Town, and aspires to be a young hero who punishes evil and promotes good. However, due to his "focal disease," he is constantly restricted by Duan Lin. The Mid-Autumn Festival river lantern festival unearths the unsolved tragedy of the sacrificial offering ceremony at Baiting Mountain. Liu Hengshun, Du Shuai, and Sun Xiaochou decide to investigate Baiting Mountain at night, discovering the Demon Cult's Holy Maiden, Xiao Bai, hiding there. After a confrontation, Liu Hengshun learns that the fire ten years ago was not an accident, and the appearance of the pipe-smoking man, the mastermind behind it all, makes the case increasingly perplexing, and the truth seems further and further away…