In this programme, Paul travels from Britain's most westerly mainland point to a place once guarded by an ancient Celtic goddess. On the way he discovers how the ancient oak woods of Loch Sunart were once a hive of industry, then goes deep underground to discover how 18th-century miners named a new element. On the shores of Loch Linnhe, he meets the owner of a castle and recreates a scene from Monty Python's Holy Grail, before ending his grand tour from the heights of the pap of Glencoe.