Ifor sets out to understand what happens when our religious urges drive us underground. His first stop is Lud's Church in Derbyshire, one of the most dramatic and eerie holy places in the land, once described as 'the place for the Devil to say matins'. Ifor then heads back 14,000 years to find evidence of perhaps the oldest holy place in Britain. He follows the path of St Cuthbert's body as it was shifted between caves in the north of England to escape the attentions of Viking raiders and visits the cave of St Govan where a hermit was miraculously enveloped in rock to evade local gangs of wreckers.