A close up view of the most destructive recent volcanic eruptions around the world.

The earth really moves in this episode as we take in scenes and stories from some of the most devastating of all the natural cataclysms: the earthquake. With all its pent-up power, nothing releases more sheer destructive energy than the grinding forces at work between the Earth's tectonic plates.

Things get personal in this episode as we really get under the skin to explore something that is a threat to all of us wherever we live: the epidemic and its global big brother, the pandemic.

Wind Storms Rip Dangerously Through Cities Around The World Showing Their Devastating And Sometimes Deadly Power Take A Look At The Engulfing Calamity Of Hurricane Katrina In New Orleans The Destructive Cyclone Nargis In Myanmar The 1960 Storm Hurricane Donna In Florida Tornado Joplin In Missouri Hurricane Sandy In New York And Many More Killer Storms

Flash floods in Brazil, the deluge that followed Hurricane Katrina, and the overflow after the Indian Ocean Tsunami of 2015 are all, to some extent, natural phenomena. But is a changing climate making them not only more likely but their impact more severe?

Ours is a dangerous world where geological mishaps—avalanches, landslides, heat waves, sinkholes and blizzards—can spell disaster almost as much as big cataclysms like earthquakes and tidal waves. While casualty counts might be lower, geological disturbances still cause their fair share of misery.