While there are terrible natural disasters like storms and tsunamis, volcanoes have a particularly horrible character. Naturally, they are more than just molten rock-spewing mountains. Volcanoes are flaming messengers of destruction and death that come from the planet's core.

Five to ten volcanoes are thought to be capable of a super-eruption that might have devastating effects on the environment. One of these volcanoes, which is submerged beneath Lake Toba in Sumatra, has erupted twice in the past million years. Is this earth-cleaving volcano erupting soon? And when it does, what's the chance of our survival?