As war breaks out, the journey of Reg Evans, a cockney lad and one of the first to volunteer to fight, is told told through moving letters to his anxious mother at home. The letters of Alan Lloyd, an upper-crust young man from Birmingham who joined the army in the same month he was married, to his new wife from the battlefields of Ypres reveal the shock of a generation of young men coming to terms with a war more terrible than anyone had foreseen. Dorothy Lawrence was determined to find a part she could play in the war… and who set off on her own to the trenches, undercover as a war correspondent. James Butlin, a young Oxford University student, whose letters indicate initial positivity on joining the conflict disintegrating into despair as the reality of trench warfare takes its toll.

The focus shifts to a changing Britain, and the lives of those left behind at home. Helen Bentwich, a clever young woman who chafed against the restrictions placed on her sex – and seized the chance to work in the arms factories at Woolwich Arsenal, before becoming appalled by the conditions there and joining a trade union. The funny diary of country vicar Andrew Clark is marked by increasing sadness as more and more men leave his village for war, never to return. The fighting is entering its darkest phase – with all hopes for a quick end dashed – but still life and love goes on… Emily Chitticks, a servant girl, falls in love with Will Martin, a soldier at a local barracks. But soon the call will come for him to go to France too…

In 1917, the war is in its darkest phase. Everyone knows victory can only come at a long, slow, and painful cost. So many lives have been lost that now men previously exempted from military service – because of their age or because their jobs were considered vital to the war effort – are called up. We hear the stories of three of them: the black Glasgow shipbuilder Arthur Roberts, sent into the Battle of Passchendaele; Duff Cooper, the dashing and debonair lover of Lady Diana Manners, the daughter of the Duke of Rutland; and Londoner Ted Poole, just 18 and the last of his fathers’ sons left alive.