The Amazon River carries a fifth of the world's fresh water through a basin that stretches from the Andes to the Atlantic, an area roughly the distance between New York and Berlin. The film follows the river from Tabatinga in Brazil downstream, tracing more than 1,100 tributaries that feed its main channel. It lingers on the meeting of the Rio Negro and the Amazon, where two rivers run side by side for miles without mixing, dark water against pale, before finally blending into one. Aerial footage covers flooded forest, river islands, and the sheer scale of a system draining nine countries. The geological history gets its own segment: until about 15 million years ago the river drained west, toward the Pacific, before the rising Andes reversed its course and sent it east across the continent instead. There is no narration built around named scientists or on-camera interviews here, mostly sweeping camera work over water and forest, treating the river itself as the main character and the flooding cycle as the engine that built the basin's shape.