Set along the southern coast of Vietnam during the French occupation in the 1940s, water is everywhere, giving life and bringing decay and rot.
Kim is 15; his father and step-mother have two buffalo, their lifeline as subsistence rice farmers.
During the rainy season, there's no grass and the buffalo are starving. Kim volunteers to take the beasts inland to find food.
On this coming-of-age journey, Kim sees men mistreat women, men fight with men, and French taxes rob the poor.
He works for Lap, a buffalo herder whose past is entangled with Kim's parents, and he makes friends who will lead him to his place in the world.