Premise: Biologist Liz Bonnin and geologist Martin Pepper travel around the world to seek answers to a series of significant earth science questions. They get down and dirty to find out how geologic events in Hawaii could wipe out Los Angeles. How much of a threat does the Campi Flegrei supervolcano, which is hidden deep in the Bay of Naples, pose to the inhabitants of Europe? What link do the Rocky Mountains have to the atomic bomb? And could the continued growth of Mount Everest start World War III? As Bonnin and Pepper view Earth's past, present and future, they reveal how the planet works.