A fantasy tale follows a farm girl who spends her entire savings to rescue a pregnant thousand-year-old white serpent from a butcher, then helps her safely give birth to her young. When a devastating flash flood strikes the rural town, the serpent summons a vast swarm of snakes to form a living bridge, saving the entire village. A resentful, greedy butcher seeks revenge through poison and arson; a squire covets the serpent's gall; a bandit leader keeps terrorizing the locals; and a governor's soldiers hunt the spirit serpent everywhere. To repay her savior, the serpent protects the family, repeatedly driving off every villain. She brings an orphaned girl and the family's son together in marriage. Later, the villains spread rumors and use sulfur traps to besiege the whole village. The orphan girl cuts her palm and uses her blood to guide the serpent, helping her break the blockade and rout the bandits. When the orphan girl nearly dies from heavy bleeding in childbirth, the serpent sacrifices a century of her cultivation to save both mother and newborn. Every wrongdoer finally receives due punishment. The serpent leaves a crystalline tear gem to the family, seals a pact of eternal guardianship, and returns to the wild ridge. The villagers erect a stone monument in memory of her kindness, and the bond between humans and the spirit serpent is passed down through generations.
