People have had a long and often fraught relationship with rocks. They have been used and abused – blown up, dug up and turned into homes and places of worship for thousands of years. Yet these days most people simply ignore them, that is unless they make a home in your shoe. Unearthing the Underworld is a history of the Earth as told through rocks – keepers of secrets of past environments, of changing climates and the pulse of life over billions of years. Even the most seemingly insignificant rock can tell us much about the history of this planet, opening vistas of ancient worlds of ice, raging floods, strange unbreathable atmospheres, and prehistoric worlds teeming with life.

Remarkably, many types of rocks owe their existence to living organisms – from the remains of bodies of dead animals, to those formed from rotting ancient forests or even created by the activity of fungi, bacteria and viruses. Anything but dull and uninteresting, rocks are intriguing portals that illuminate the secret underworld upon which we live.