Aluna is a 2012 feature-length documentary film sequel to the 1990 BBC documentary From the Heart of The World: Elder Brother's Warning. The first documentary showed an ancient Kogi tribe civilisation (the Elder Brother) who emerge to offer their concern for people of the modern world (Younger Brother). Younger Brother is urged to change or suffer environmental disaster. After offering the warning, the Kogi retreat to their community hidden in the mountains of the Sierra Nevada de Santa Marta, Colombia.In the second documentary, the Kogis have re-emerged, realising that the importance of their warning was not grasped. As well as warning Younger Brother, they have decided to share their understandings of how nature works in the belief that doing so will share their burden of healing the dying planet.