April 1940: Nazi Germany has invaded neutral Norway. Fleeing north from their brutal blitzkrieg advance are three officers of the King's Guard - men who have been entrusted by the Norwegian King with a vitally important mission. The only military force which stands between the Nazi forces and total victory are the poorly equipped, undertrained squaddies of the British 148th Brigade. Among them is Sergeant Jack Tanner, recently returned from the Middle East. As the British are pushed back from Lillehammer, Sergeant Tanner and his patrol are left stranded in the mountains in the chaos of retreat. Trying to re-join their unit, they stumble first across Sandvold and his protectors, and then a French patrol of Alpine troops.
Trekking through snow-clad mountains with the Germans dogging their every move, Tanner is forced to try and out-fox and out-fight not only their pursuers but the best efforts of his own side. And as the Allies' resistance collapses, it quickly becomes clear that the small band of fugitives can rely on no one but themselves.