Ben returns to Taransay, the island where, over 20 years ago, he took part in the TV show Castaway. He visits the stunning Luskentyre Beach on Harris and joins local community members to learn how the island's remoteness from hectic urban life sustains the sanctity of the Protestant Sabbath and how that peacefulness impacts on faith and worship. In Tarbert, Ben joins up with former bio-chemist Abdul, a Muslim in the township, who reveals how his own faith's values harmonise with Harris's traditional Protestant ethics and that, after 20 years here, he feels closer to God than anywhere else. Crossing the island isthmus to Lewis, Ben spends a night of solitude and reflection in a clifftop bothy overlooking the Atlantic and joins Norma Macleod on a wild-water sea swim from Bosta Beach. Recently diagnosed with cancer, Norma uses cold-water swimming to reset her mind, body and soul. Visiting the mysterious Standing Stones of Calanais, Ben learns of the local myth that the great slabs are giants turned to stone for refusing to convert to Christianity. To discover more about the pre-Christian faith of Lewis, Ben joins archaeologist Ian McHardy to climb a 40-metre-high sea stack, where dramatic funeral pyres burned 7,000 years ago. In Stornoway, Ben learns how the Iolaire tragedy — the UK's worst peacetime shipping disaster after the Titanic — has shaped the island's faith. He meets Margaret Ferguson, an artist painting the portraits of all 201 victims, who explains how her work is helping to heal a community after a century of silent mourning.