Josh investigates how a group of Norse tribesman gained power in medieval Europe. His search for answers begins in their one-time home base of Denmark and continues on to the first place they expanded off the continent, the remote island of Iceland.

Josh travels to his ancestral home of Great Britain to explore the origins of Stonehenge. From high in the air to deep under the sea, he finds an unexpected network of monuments that could have inspired one of history's most mystical locations.