Between Silk and Cyanide: A Codemaker's War, 1941-1945

Leo Marks joined SOE in 1942 at the age of twenty-two. A cryptographer of genius, he had revolutionized code-making by the time he was twenty-three. In replacing the outdated and dangerous poem codes with an ingenious system of one-time codes printed on silk that could easily be destroyed, Marks was instrumental in both stymieing German counter-intelligence and saving hundreds of agent's lives. He discloses how and why he broke General de Gaulle's secret code; details the adventures of saboteurs who parachuted into Norway to destroy a heavy water plant; did surveillance on Hitler's long-range missile base at Pennemunde; and organized the secret armies of occupied Europe building up to D-Day.