The inhabitants of a small island in the delta of the turbulent Red River are doomed to poverty: floods wash away crops, livestock, and even people. From generation to generation, a legend is passed down about a kind dragon that can drink the river's water and save the village. But the dragon is a fairy tale, and the people have decided to block the treacherous river themselves. With extraordinary perseverance, fighting against the elements, the village population builds protective fortifications around the island.