This episode follows the immense journeys of the Amazon, Nile, and Yangtze—three of the world’s longest rivers—and explores how they shape ecosystems, cultures, and civilizations. It highlights the Amazon’s unmatched biodiversity and climate-regulating power, the Nile’s central role in sustaining life and history across arid lands, and the Yangtze’s influence on trade, agriculture, and modern development in Asia. The episode also examines shared environmental threats such as deforestation, pollution, dams, and climate change, emphasizing the need for cooperation and sustainable river management. Ultimately, it shows that the world’s longest rivers are not just geographic features, but living connections that sustain life from source to sea.