Jiang Yue, a technician at an aquatic research institute, opens her eyes after a laboratory accident to find herself an outsider in a fantastical tribe. The tribe, called the Green Scales, lives by the water but has feared the fish in it for generations. Tribal law declares that the fish are descendants of the Water God, and anyone who touches them will suffer divine punishment. Looking at her starving tribespeople, whose bodies are little more than skin and bones, and the plump schools of fish at the bottom of the river that no one dares to touch, Jiang Yue silently digs the first fish pond on the riverbank. From weaving fish traps and raising fry to formulating feed and preventing diseases, she uses modern aquaculture techniques to give this nearly extinct tribe its first full meal.