In the early Republican era, a koi fish that had cultivated for a thousand years was on the verge of transforming into human form—only to be captured by a fishmonger. At that critical moment, Madam Su Wan, wife of a powerful warlord, passed by with her young son, Si Jinchen. Moved by compassion, she rescued the koi and set it free. A year later, the koi finally takes human form as an eight-year-old girl named Linglong. Determined to repay their kindness, she sets out to find her benefactors. Meanwhile, young master Si Jinchen falls gravely ill, and none of the doctors in the mansion can cure him. Linglong, sensing her savior is in danger, breaks into the warlord’s residence and uses her spiritual powers to heal him…