<p>Henry Rush is spending the day at the Prairie Wildlife Refuge, determined to photograph a prairie dog doing a back flip. But while he whatches and waites at the edge of prairie dog town, he fails to notice the electricity humming through the air. Or the buffalo aniously pawing the ground. Or the purple-blue cloud building over the prairie grass. A tornado is forming to the west . And when the dark funnel touches down, it will wipe out everything in it's path...