In this third and final episode, the pilgrims head north east to Moray on the edge of the Scottish Highlands. Their first stop is Pluscarden Abbey, Britain's only working medieval monastery. Keen to see how these current-day Benedictine monks live and work, the pilgrims stay overnight and sample some of the routines of monastic life, which include helping with domestic duties. As they question the monks about their life choices, Monty, Louisa, Will and Nick fruit pick in the orchards, while Lawrence, Shazia and Scarlett start cooking dinner. But over supper, and after attending a service conducted in Latin, the group's first proper argument erupts over a few misplaced words.By the following morning, all tensions are forgotten, and the pilgrims head off to Forres, a nearby ancient town dating back to around AD900. Louisa, Shazia, Scarlett and Will discover the Witches Stone, a memorial to so-called witches killed in the area during the Middle Ages. Meanwhile, Lawrence, Monty and Nick seek out Sueno's Stone, a famous Christian Pictish monument thought to be evidence that, three centuries after Columba's death, Christianity had reached the territory inhabited by pagan Picts.The pilgrims head west across the Highlands and catch a ferry to the Outer Hebrides and the Isle of Lewis. In Stornoway, Shazia takes the chance to pray at Britain's northern-most mosque, taking Nick and Louisa with her. After the service, they're invited to stay for tea when they find out more about this small, friendly Muslim community. Once reunited with the other pilgrims, they head to the Calanais Stones, which are older than Stonehenge. While Lawrence ponders how Columba would have reacted to these pagan megaliths, Shazia shares that with any place of pilgrimage, its significance is not what it is, but the faith you have in it.The pilgrims then start heading back south on the Scottish mainland towards the Inner Hebrides. On the way, they stop off for a wet and wild walk in Glen Nevis in the shadow of Ben Nevis, the highest mountain in the UK, and with Columba's Isle now only two days away, their thoughts start turning to the end of their pilgrimage and their own personal spiritual journeys.Another ferry ride gets them to the Isle of Mull - just a hop away from Iona - and their last overnight stop, where they sit down together to celebrate their journey and Columba. Early the following morning, day 15 of their pilgrimage, local boatmen take them on the final leg of their pilgrimage, from Mull to the tiny island of Iona.The current abbey on Iona was founded in the 13th century over the foundations of Columba's original 6th-century monastery, but it was Columba's settlement which made Iona an island famed for its scholarship and culture. The pilgrims visit the shrine where it's most likely Columba was buried, and a last walk to the hill of Iona brings about an emotional farewell to their pilgrimage, with the final words belonging to Nick, who salutes the memory of Columba and his achievements.