Michael travels through Britain and northern France uncovering railway stories from the Great War. He gets hands-on experience of the miniature tracks and trains that kept supplies flowing to the front line and visits North Eastern Railway Headquarters in York to find out about the Great War's forgotten railway leader. He hears the story of the Bath railway poet, and pays homage at the site of Britain's deadliest train crash in Quintinshill. Finally, Michael crosses the Channel to discover how the railways fed millions of men in the trenches from a depot in Abancourt.

In this final episode, Michael explores the aftermath of this earth-shattering conflict. For four years, the railways had fed the front line with vast numbers of men, munitions and supplies. But even after the armistice had been signed in a railway carriage, the work of the railways was not done. As Britain continued to mourn its dead, the railways played an important part in their remembrance. Michael hears stories of railway war heroes and encounters a remarkable railway wagon used to honour them. He hears how the railways helped give birth to battlefield tourism, and in the cemeteries of Ypres he meets the great-grandchildren of some of the fallen.