Of all our planet's forces, perhaps none has greater power over us. Our struggle to control it has been behind the rise and fall of some of our greatest civilizations. In Africa we'll rediscover how early communities found water underground in the desert, and how this guided their food supply and economy.

Dr. Stewart travels into the Earth's crust to understand Mother Nature's forces. We begin almost a thousand feet below the surface in a geological wonder: the Naica crystal cave in Mexico. It's an environment so hostile that anyone entering the cave would die in less than 30 minutes. Then we jet over to Israel's Negev Desert, where we'll uncover man's earliest source of copper, which changed our relationship with the planet forever.

Empires have risen and fallen on the tide of changing storm patterns and the turbulent relationship between atmosphere, landscape and oceans. We'll learn about the impact of the Himalayas on new wind patterns, then jet over to Australia's Red Center, where a giant swirl of wind has relentlessly stripped the land of its fertility, forcing its Aboriginal people to survive as hunter-gatherers while civilizations elsewhere developed agriculture.

This is the story of the Earths greatest gift to humanity, and how it has shaped the development of our civilization. That gift is fire. From the earliest hearth fires have kept us warm, cooked our food, and provided light. Today we have found a few more uses for fire. Our ability to master fire has driven human history.

Geology has shaped human history, but humans are a force of nature ourselves, and we have changed geology. We can see this in action in Indonesia, where volcanoes spew out boiling mud instead of lava, as a result of man-made underground tunnels used to probe for natural gas. On the other side of the planet, we'll travel to the Canadian Rockies to peel back the historic record locked in ancient ice to see how man's earliest agriculture may have sparked global warming.