Agricultural graduate Lin Yan returns to the village and, despite his father's doubts, insists on trial-planting Dioscorea cirrhosa on barren slopes to supply dye for the intangible cultural heritageXiangyunsha. Through soil testing, ditch modification, drought resistance, and rush harvesting, and after experiencing failures in rotting seeds and maturity rates, with the help of Su He, Uncle Chen, and his father, he connects the cultivation end with the sun-crying and mud-dyeing processes into a closed loop, allowing "black gold to grow in the soil" and turning returning home into a new path.