Village woman Yara Lane was beaten to death by her gambler husband. Emerald, a snake demon who was once saved by Yara, uses a hundred years of cultivation to possess Yara's body and resurrect her. She uses her snake power to protect her daughters, punish villains, and cut off ties with her leeching in-laws. She supports her daughters' education, renaming them Hope Lane and Ann Lane. She accepts a reward to harvest the Crimson Demon Vine to save Marquis Howard, earning a thousand taels of gold; later she saves the emperor and is awarded an imperial plaque reading 'Divine Healer Reborn'. Her daughters grow up to be successful: one becomes a renowned healer, the other a respected Legal Advisor. As the Heavenly Tribulation for her demon form approaches, she ascends to immortality by surviving the tribulation on a lonely peak, and guards the mortal world from the clouds above.
