Summoned to war-torn Bosnia, ex-SAS officer Jeff Hawkins' main role is to keep UN aid convoys running at all costs. But his new company commander isn't up to the job and his colleague in Liaison is running his own agenda. The arrival of the winter snow brings another problem. It's vital that one huge convoy runs the gauntlet of fighting along the icy mountain roads, breaking the siege of Sarajevo with essential provisions and medical supplies before Christmas. 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.