Nézze meg a Teljes Film Magyarul. The scientist Udo Gierer is on the trail of Theodor Koch-Grünberg, the famous Amazon researcher at the beginning of our century. While traveling on a river steamboat, he meets and becomes friends with 14 year old José Junior. He takes José with him on a flight over the rain forest and tells the boy about the importance of the Amazon as the lung of the world.