Dr. Gabriel Proudmore wanted to leave Aberdeen Scotland and journey to the Southwestern States. Chancing upon the schooner Heimdall, on the docks one evening, he's given an opportunity to embark with her crew on a journey retracing the original route the Rognvald Vikings had taken to Southwestern America. With equal amounts of eagerness and trepidation Gabriel joins and, after many months of challenging adventures they finally reach San Diego. Forced to put the schooner into dry-dock for repairs and modifications, the team decides to holiday in Southern Utah so they can rendezvous with the Professor, a brilliant confidant from Rabat. What he shares at the summit stuns the crew and changes their plans. Now, instead of sailing north to Montague Island, four of the crew will travel to a hidden base in Taroudant Morocco for secret training on state-of-the-art vessels. The others will journey into the Anza Borrego and climb Ghost Mountain to verify what GRACE 2 Satellite Surveillance has recently discovered, an entrance into a vast Underground River system. Tearfully, both groups part company to prepare for the greatest challenge of their collective lives, an extraordinary mission into a numinous subterranean realm in search of century's old Viking civilizations.