The 'cooee' call to arms takes Syd from the Mallee to the fields of France. As part of the mobile veterinary unit, his horses are trained for war but face new and deadly weapons. Battle-weary diggers, shipped from Gallipoli and joined by fresh recruits from home, are met by a formidable enemy at Fromelles and along the River Somme, in a year that will be forged in legend and memory, in the trenches and the conscription battles at home.