From the Heart of the World: The Elder Brothers' Warning (1992)

The Kogi are the last surviving civilization from the days of the Inca and Aztec. They see themselves as the spiritual guardians of life on earth. For four centuries they lived in seclusion in the Sierra Nevada mountains, carefully guarding their isolation. When the tribal elders began observing signs of ecological crisis in the changing patterns of snow and bird migration, they emerged from their seclusion, inviting BBC filmmaker Alan Ereira to record their prophetic message to the world.