Read Anthony, Fisher David. Operation Lucy: The Most Secret Spy Ring of the Second World War

Coward, McCann and Geoghegan, 1981. — 270 p.Switzerland, 1939. As the Second World War loomed on the horizon and Stalin kept his cautious peace with Hitler, the last links in what would be one of the war's crucial espionage networks were being forged in neutral Geneva. Code-named Lucy, this clandestine operation involved a group of Soviet expatriates who would in the next four years become Moscow's watchdog on the West and their most effective defense against the advancing Nazis.