The team embark on a journey from the most northerly tip of the British Isles, Muckle Flugga on Shetland, to the Old Man of Hoy on Orkney. Neil Oliver joins an expedition to climb the Old Man of Hoy, a terrifying vertical column of sheer rock that was only conquered for the first time in 1966. Neil also discovers the remarkable story of the Second World War freedom fighters who risked everything running the Shetland Bus, a series of top secret missions into Nazi-occupied Norway. Bone expert Dr Alice Roberts unearths a mysterious skeleton which reveals the surprising lifestyle of ancient Shetlanders. Miranda Krestovnikoff dives into the crystal clear waters off Orkney in search of the elusive octopus who love to feast on lobster. Nicholas Crane discovers evidence of a giant tsunami, a seven-thousand-year-old tidal wave which devastated Britain. And Mark Horton explores dangerous waters - he joins one of the world's most sophisticated survey ships on a mission to find the uncharted hazards that wreck unwary vessels.