Thirty miles from mainland Scotland, there is a chain of low-lying islands that face the full might of the Atlantic Ocean: the Uists and Benbecula. On these islands there seems to be more water than land, as a spectacular patchwork of freshwater lochs and pools pockmark the landscape. But it is the unique ecology of these unspoilt islands that makes them so special. Paul's journey sees him trying his hand at fishing for wild sea trout, uncovering the fascinating story of how South Uist became a missile testing base, and discovering the secrets of the beautiful but deserted tidal island of Vallay.