Gordon Corera uses declassified documents and extensive original research to tell the story of MI14(d) and the Secret Pigeon Service for the first time. Between 1941 and 1944, sixteen thousand plucky homing pigeons were dropped in an arc from Bordeaux to Copenhagen as part of 'Columba' – a secret British operation to bring back intelligence from those living under Nazi occupation. The messages flooded back written on tiny pieces of rice paper tucked into canisters and tied to the legs of the birds. Authentic voices from rural France, the Netherlands and Belgium – they were sometimes comic, often tragic and occasionally invaluable with details of German troop movements and fortifications, new Nazi weapons, radar system or the deployment of the feared V-1 and V-2 rockets that terrorized London.