In the eighteenth century, the received wisdom, following Ussher's careful biblical calculations, was that the Earth was just six thousand years old. James Hutton, a gentleman farmer with legal and medical training and a passion for rocks, knew that this could not be the case. Looking at the formation of irregular strata in the layers of the earth he deduced that a much deeper abyss of time would be required for the landscape he saw to have evolved. In the turbulent world of Enlightenment Scotland he set out to prove it. He could not have achieved this without his friends. Hutton's entourage in Edinburgh would turn out to be the leading thinkers of the age. His close circle consisted of such luminaries as Erasmus Darwin, Adam Smith, James Watt and David Hume. These brilliant men would work together to develop the nascent science of geology but would also make spectacular advances in agriculture, chemistry, philosophy, economy and engineering; as well as devising steam engines and military tactics. Hutton's geological theory of the Earth would cause a profound religious debate as well as provoking decades of criticism. His revelation, however, was ultimately one of the most extraordinary and essential moments in scientific history. This is the little-known story of a man who fought hard against orthodox beliefs to prove the antiquity of the earth and of the dedicated loyalty of an enlightened circle of friends.