A modern teenage girl unexpectedly soul-travels into a chaotic era of demons as Jiang Yuechu, the daughter of a disgraced official. Awakening at the start in a desperate deadlock of a mountain of corpses, she fortuitously awakens the Hundred Demons Manual which can slay demons to gain Taoist cultivation and replicate demonic powers. Forsaking self-preserving selfishness, she joins the Demon Suppression Guard, hurries across various regions of Longyou, quells wolf demon turmoils, resolves Black River disasters, defends Yumenguan to the death, and personally purges various demons and monsters that ruthlessly harm the common people. Even while carrying the burden of old family cases, maneuvering between the imperial court and the dark undercurrents of the Western Region demon court, she consistently upholds the righteous path of protecting the people, growing step by step with her unyielding backbone and compassionate heart, guarding the western frontier with her mortal body, and becoming Adult Jiang whom demons fear at the mere mention and upon whom the people rely with peace of mind.