Steve embarks on one of his most dangerous expeditions. His mission is to explore Venezuela's tempuis - he will explore the lost worlds cut off from the jungle below. He will be joined by an elite team of rock climbers. The team will encounter river rapids and hazardous wildlife, and survive a close shave with a rickety biplane.
The naturalist reaches the peak of one of Venezuela's tepui mountains, before joining a party of Italian cavers as they venture into the unexplored caverns within. Inside, they discover strange wildlife and evidence of the geological forces that give the tepuis their unusual shape. Finally, the team returns to the ground by abseiling down the Angel Falls, the world's highest waterfall