1992: Ex-SAS officer Jeff Hawkins is summoned to Bosnia, where his role is to keep the UN aid convoys running at all costs. But Hawkins soon realises he's been pitched into a task far more dangerous than he had imagined. His new Company commander isn't up to the job; his colleague in Liaison is tied up with the British Secret Service and running his own agenda; the uneasy alliance of local Muslims and Croats against the Serbs is about to break down with the arrival of Islamic fundamentalist fighters from Afghanistan. Then there's the small matter of mercenaries for hire and the CIA stirring the pot for their own ends. Only the arrival of the winter snow in the rugged mountains of Bosnia brings a welcome lull to the mayhem. But it also brings another huge problem: it's vital that one massive convoy runs the gauntlet of the fighting along the icy mountain roads, breaking the siege of Sarajevo with vital provisions and medical supplies before Christmas. And that it makes the return trip, bringing orphans, the sick and elderly back to safety. Defying all odds, the twin-air horns of a hundred trucks blast defiantly as their giant wheels begin to roll on a journey to hell and back ...