Top Gear's own Richard Hammond leaves Jeremy and James behind and embarks on his own quest to explore beneath the earth's surface using satellite photos and 3D imagery of the planet, hoping to discover more about our planet's complexities. Hammond will go on to explain where volcanoes come from, why earthquakes happen and, oddly enough, how sea turtles use the magnetic field of the earth as a navigation system. Probably better than any GPS Hammond has used to this point, anyway.