The work of the Queen’s Foreign Service messengers, who carry the diplomatic despatches from the Foreign Office in London to British embassies all over the world. In these modern times, we see how he journeys by air - where, for hundreds of years, his predecessors went by post-chaise or on horse-back. In those days, each man carried a pair of pistols and a sword. Today — an outsize passport, printed and bound in red. One thing only persists - the secret token once used as a pass-sign, a relic of the War of the Roses - the Silver Greyhound.