We follow Iain on the 47 miles from Glasgow to the halfway point at Crianlarich. Accompanying him on day one of his adventure is his Small Faces screen brother, Stephen Duffy, who walks with him on the first 20 miles, starting in Milngavie. On reaching Loch Lomond, chef and restaurateur Guy Cowan and Takin’ Over the Asylum writer Donna Franceschild join Iain, and they share a posh packed lunch on the banks and perform a dramatic dog rescue. Iain also makes a disastrous attempt at kayaking before catching up with River City co-star Lesley Hart in Crianlarich.

Iain takes on the last 52 miles of the iconic trip joined by familiar faces along the way. A week into adventure, he and his River City co-star Lesley Hart start with an easy six-mile walk from Crianlarich to Tyndrum. On his journey, an astonished Iain enters the mist-swirling valley of Glencoe, while a rained-off climb sees him reunited with Small Faces actor Stephen Duffy. With some challenges, a relieved Iain makes it across the Devil's Staircase while he enjoys a day in the small town of Kinlochleven. Exhausted, he finally descends into Fort William before ascending to Scotland's ceiling by climbing Ben Nevis.