The desolate frontier village called Mang was plagued by a devastating rat infestation. Led by the cunning rat demon Hui Xian, the swarm ravaged crops and grain stores, leaving the villagers in despair. Desperate for a solution, the village chief, Hou Yongfu, sought out Huang Huotu, a renowned rat exterminator. Huang Huotu, willing to sacrifice three years of his own lifespan, used his own vital essence and lifeblood to slay Hui Xian, bringing the rat disaster to an end. His only request for payment was a single pig, which he intended to use to fund treatment for his wife, Mei Yuling, who was suffering from tuberculosis.
No sooner had the rat infestation subsided than Hou Yongfu and his son reneged on their promise. Upon returning to the village, Hou Dayong mocked Huang Huotu, calling him a fraud. The villagers, swayed by the prospect of cheaper services, turned to Wang Mazi, a self-proclaimed rat catcher armed with a fake ultrasonic device certification. Despite Huang Huotu's repeated warnings, the villagers disregarded his advice. They destroyed his rat repellents, slaughtered livestock indiscriminately, and even killed the guardian spirit snake that had been protecting the village. When shepherd Wang Erleng ignored the safety boundaries and ventured out, he was devoured by the rats. Yet, the villagers refused to reflect on their actions.
Determined to combat the rising evil, Huang Huotu set off for the county overnight to borrow the Evil-Bane Sword, leaving behind the Bone Flute of Rat Pacification for Mei Yuling. While Huang was away, Wang Mazi, overcome by depraved lust, attempted to assault Mei Yuling. When she resisted, he concocted a vile scheme, accusing her of being the demon responsible for summoning the rats. The gullible and ignorant villagers, blinded by their susceptibility to manipulation and forgetting the life-saving sacrifices made by Mei and Huang, believed Wang's lies. United in their misplaced hatred, they strung Mei Yuling to her death from the branches of a towering tree.
When Huang Huotu returned and found his wife's lifeless body, his grief and despair knew no bounds. In his anguish, he played the Bone Flute of Rat Pacification, summoning an immense swarm of rats that engulfed the village. The ungrateful villagers, the malicious Wang Mazi, and the selfish Hou Yongfu and his son all perished in the ensuing chaos. With his vengeance fulfilled, Huang Huotu buried his wife with great sorrow. Among the ruins, he discovered Er Ya, a kind-hearted orphan girl who bore a talisman bearing the protective symbol of a cat. Resolving to leave the cursed village behind, Huang took the child with him, vowing to shield her from the deep-seated greed and cruelty within human nature. Together, they departed, leaving behind a land scarred by betrayal and tragedy, as Huang Huotu saw through the darkness that lay in the depths of human nature.
