This photograph was made deep in the Brazilian Amazon on the Rio Negro, where the high-water season floods vast stretches of forest. Our wildlife photography expedition took us far upriver in search of the region’s unique species, but the unmistakable stars of the journey were the Amazon river dolphins—curious, slow-moving, and unlike any other dolphin on Earth. While diving in the tannin-rich ‘blackwater,’ one dolphin approached, illuminated by shafts of sunlight filtering through the surface. The copper-red glow you see is the natural light refracting through the dark water, revealing the dolphin’s distinctive form in this rare and intimate encounter.