For seventy years they guarded the British Empire. Oblivion and Fogg, inseparable friends, bound together by a shared fate. Until one night in Berlin, in the aftermath of the Second World War, and a secret that tore them apart. But there must always be an account...and the past has a habit of catching up to the present. Now, recalled to the Retirement Bureau from which no one can retire, Fogg and Oblivion must face up to a past of terrible war and unacknowledged heroism, - a life of dusty corridors and secret rooms, of furtive meetings and blood-stained fields - to answer one last, impossible question: What makes a hero?