Beneath Yellowstone National Park a super-volcano has started rumbling. It's been there for a very long time, though most Americans are not aware of it. Every three hundred thousand years or so it erupts with devastating consequences. Scientists say it's getting ready to erupt. Naysayers say it's a hoax. The Interior Department closes the park and orders an evacuation. Most people comply, and those who don't stay behind knowing they're risking a very...