Volcanoes are one of nature’s most awesome and destructive forces, but they are also the life force and architect of our planet. They can raise up great mountains and create new land, or they can level cities and destroy entire civilizations. They provide a glimpse of the power of Earth’s internal heat source, without which it would have become a dead planet millions of years ago. In this episode, Iain takes us on a journey to some of the most dramatic places on Earth, starting in Ethiopia.

From flightless cormorants hunting underwater to giant tortoises courting on the rim of an active volcano, a look at the hidden side of Galapagos, revealing why it is such a fascinating showcase for evolution.

SETTING: 72 million years ago, near present-day Montana. As a young male daspletosaurus, it's Das' job to herd unsuspecting prey towards the rest of the pack. But he's easily distracted and ruins several hunts getting him in deep trouble with his mother, the pack leader. When a volcano threatens, the dinosaurs are unprepared.

Do other worlds tremble and heave with geological life? On Mars, we found a volcano to dwarf Mount Everest. On the moons of the giants our understanding of volcanoes was changed forever.

Without words, Ron Fricke shows us the world, with an emphasis not on 'where,' but on 'what's there.' It begins with morning, natural landscapes and people at prayer: volcanoes, water falls, veldts, and forests; several hundred Balinese Hindu men perform kecak, the monkey chant. Indigenous peoples apply body paint; whole villages dance. The film moves to destruction of nature via logging, blasting, and strip mining. Images of poverty, rapid urban life, and factories give way to war, concentration camps, and mass graves. Ancient ruins come into view, and then a sacred river where pilgrims bathe and funeral pyres burn. Prayer and nature return. A monk rings a huge bell; stars wheel across the sky. (Click CC for places description)