Chen Laohei, a duck herder on the Baishui River, is driven away by Zhang Qiming, a manager who has returned from overseas, with nothing but a written agreement. This disrupts the ecological balance and leads to a devastating locust infestation. To protect his crops, Zhang Qiming illegally uses highly toxic pesticides and is caught and punished. Locusts devour crops throughout the county, leaving farmers facing total harvest failure. In the end, Chen Laohei returns to the fields with 100,000 ducks, eliminates the pests, and saves the harvest. The story reveals the value of traditional ecological wisdom.