Paul begins with a chilly swim across Loch Ba high on Rannoch Moor, struggles against the elements while trainspotting and meets some veteran Tunnel Tigers - men who tunnelled deep inside the Grampians, diverting water to hydroelectric plants. Paul then travels into the secret heart of the Rough Bounds of Knoydart by way of Loch nan Umbh, Loch Morar, Loch Nevis and Loch Arkaig. He exposes the area's secret connection with the celebrated SOE (Special Operations Executive), which Churchill hoped would set Europe ablaze. On the shores of several lochs, agents were trained in the dark arts of sabotage. On Loch Morar, Paul meets a man who claims to have seen the legendary monster Morag (pronounced Voorag). The episode concludes with a ferry to Inverie in the heart of the Rough Bounds, and searching for Jacobite gold beside Loch Arkaig.