Lying about his age to join the army, Edinburgh teenager Jamie Melville comes to the attention of his battalion's new colonel, Winston Churchill, who is seeking redemption in the trenches as an ordinary soldier after his resignation over the Dardanelles fiasco in 1915. Jamie becomes the colonel's new 'batman' and is soon thrust into the line of fire.

After the conflict, Churchill returns to the cabinet and Jamie's service continues as assistant to Winston's private secretary. In this new world, he will learn how to do battle on a very different front, and meet some of the extraordinary characters who inhabit wartime London - all whilst trying to piece together his broken family, and fighting for a life he can call his own.