During the Second World War, officers in the British and American Intelligence agencies reported links with the Vatican in Rome. This documentary history uses first-hand evidence, telegrams, letters, memoranda and photographs found in files deposited in the National Archives in Kew, London, It investigates the links between the representatives of the Special Operation Executive (SOE), Britain's subversive intelligence agency, and the Office of Strategic Services (OSS), its American equivalent, in Berne, Switzerland, and Adriano Olivetti, an Italian industrialist. He wanted Allied help in coordinating the coup against dictator Benito Mussolini's Fascist government with the Allies' invasion plans. When Pierre Osterreith, a lieutenant in the Belgian Army, fled to Britain in 1941, he was recruited by the British Political Warfare Executive (PWE), a clandestine organisation dedicated to producing and disseminating white and black propaganda. Trained by SOE and briefed by PWE, he was parachuted into Belgium in August 1942 to contact leading Belgian industrialists. When a message reached London that he had been captured on landing and imprisoned by the Germans, members of his family planned to ask the Vatican to plead for his release. Mr and Mrs Weiss, Austrian refugees in Britain, were recruited by the SOE and trained for a mission in Italy where they were to contact leading figures in the Vatican and try to encourage support for a Catholic resistance organisation in Austria. Monseigneur Hugh O'Flaherty, an Irish official in the Vatican, organised the Rome Escape Line, a group financed by MI9, part of the Secret Intelligence Service (SIS). Set up to train escape and evasion methods to members of the Armed Forces, it financed those who helped escaped prisoners of war, downed pilots, air crew and other refugees fleeing Nazi persecution to reach Britain. Helen Ten Cate Brouwer was a German-trained wireless operator from Belgium who handed herself in to the Allies in Rome and provided details of Nazi activities in Italy and the Vatican. Cesare de Amicis was a German-trained Italian saboteur, the head of the 'Rome Sabotage Gang' which was captured by the Americans and interrogated. His report sheds light on the Abwehr, Germany's military intelligence service, their plans to attack the Allies' supply lines, and their intrigues in the Vatican.