Dao Shuangshou returns home to promote rice-fish co-culture, hoping to make the paddies yield both rice and fish, but faces skepticism from Dao Laotian. He teams up with Su Xiaoyu to test the waters by stocking fry, recording water temperature and fry growth, and proving with facts that fish can weed and loosen soil without harming the rice roots. The project gradually expands, developing into rice-fish grain sales and tourism experiences. When a heavy rainstorm arrives, everyone reinforces the enclosure nets and dredges the ditches to guard the rice paddies. After the harvest, rice production increases, fresh fish income rises, and Dao Laotian shifts from opposition to taking the lead in expanding planting. Eventually, the whole village promotes rice-fish co-culture, and one paddy with a double harvest becomes a new path to prosperity, with agricultural tourism developing more and more prosperously.