It's 1916, and war is raging on France's Western Front. Bill Parker and Jack Reynolds, best mates and Aussie larrikins, as well as veterans and heroes of Gallipoli and the Western Front, are chosen by the British Intelligence to carry out a secret mission behind German lines. A rogue German scientist has developed a deadly gas that can kill almost instantaneously. Together with a homicidal American mercenary, they have forced captured Allied POWs to construct a POW camp with a built-in battlefield, trenches and all, in the Bulgarian hinterland. Their plan is to test the effects of the gas on the live Allied prisoners for the German general staff. If successful, the gas will be mass produced and deployed on the Front, resulting in certain victory for Germany and hundreds of thousands of Allied lives lost. Parker and Reynolds track them across Europe and Africa on a desperate race against time, fighting running battles with conventional German forces all the while, to a final confrontation in deepest Africa. Bill Parker's dreams of his life and his love back home in Australia play an integral part in his survival and the outcome of his mission.