Dusk is gathering as a young priest, Christopher Fairfax, rides across a silent land. It's a crime to be out after dark, and Fairfax knows he must arrive at his destination - a remote village in the wilds of Exmoor - before night falls and curfew is imposed. He's lost and he's becoming anxious as he slowly picks his way across a countryside strewn with the ancient artefacts of a civilisation that seems to have ended in cataclysm. What Fairfax cannot know is that, in the days and weeks to come, everything he believes in will be tested to destruction, as he uncovers a secret that is as dangerous as it is terrifying ...