I am particularly grateful to Richard Callaghan, curator of the Royal Military Police Museum, and to Lieutenant Colonel Parkinson, head of Media and Protocol at Sandhurst. I am also indebted to Bob Gratton and Dale Coton, both of the Ashover Light Railway; to Rupert Lodge of the Leighton Buzzard Railway, and David Negus of the Southwold Railway Trust; to Dr John Bourne, of the Centre for First World War Studies at the University of Birmingham; to Major David James-Roll, and to F. Martin. All embellishment of the historical facts, and all mistakes, are mine and not theirs.