The naturalist attempts an ascent of a rock-face that has never been climbed previously to explore the jungle atop a tepui and see what wildlife lives there. To get there he braves a rickety biplane, rapids and local fauna.
The naturalist reaches the summit of one of the tepuis and then joins a team of Italian cavers exploring the network of unexplored caverns inside another. Finally, the team abseil down the world's highest waterfall.