After three months of severe drought, orphan Su He faces her grandmother and fourth uncle who are seizing land and forcing debt collection. Relying on her mother's legacy notes, she finds a spring in the back mountain and fights desperately to keep three fen of lean land. She softens the hardened yellow soil with mountain spring water, breaks ridges with wild potatoes, treats pests with plant ash, and survives crises such as pestilence, gentry land-grabbing, grain merchants' price suppression, heavy snow destroying seedlings, and saline-alkali backlash. Hunter Lin Yan helps her all the way, and villagers from two villages shift from opposition to unity, building dams and digging canals, setting up greenhouses, and eliminating rat infestations, ultimately turning the barren land into fertile fields. Su He politely declines an official position and donates the "Qingxi Agricultural Book", making her village the first agricultural demonstration village of the Yunhe Dynasty.