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: to get leading scientist, Hening Sandvold, out of Oslo and away to the safety of the Allies. 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 to join the King's Own Yorkshire Rangers. 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 rejoin their unit, they stumble first across Sandvold and his protectors, and then a French patrol of alpine troops. The odds of this ragtag group of soldiers and civilians making it to safety are stacked against them.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. Yet Tanner knows he has to succeed. For, as he discovers, Sandvold holds the key to a vital secret - one that could change the outcome of the entire war...