When the full might of Nazi Germany descended without warning upon neutral Norway in April 1940, many brave Norwegians wanted to escape to Britain to join the fight against the occupation of their country. The most natural route to freedom was to take to the cruel North Sea in small boats, following in the ancient traditions of their Viking ancestors. Facing perils of betrayal by collaborators and pursuit by the Gestapo, these brave Norwegians were in flight, but they were absolutely determined to return as avengers of Nazi oppression. For the first time, the stories of these remarkable escapes have been woven together into a single comprehensive Viking saga, set in the social and military context of the Nazi occupation. Extensive research has revealed many new boats and dramatic escapes, with at least 360 boats carrying over 4,000 fugitives now known to have crossed to the Allies. The onward progress of the avenging escapers is followed into the renowned Kompani Linge commandos, the famous Shetland Bus and the other free forces. Attempts by German intelligence to infiltrate spies are revealed - and how most of them were caught and turned into double agents. Hitler had dreams of turning Norway into a semi- autonomous Aryan utopia, but he was to be confounded by the obstinate defiance of the Norwegian people, and by the free Vikings who returned to wage war against him.