Winston Churchill famously instructed the head of the Special Operations Executive to “Set Europe ablaze!” Agents of both the British Special Operations Executive and the American Office of Strategic Services underwent rigorous training before making their way, undetected, into Occupied Europe. Working alone or in small cells, often cooperating with local resistance groups, agents undertook missions behind enemy lines involving sabotage, subversion, organizing resistance groups and intelligence-gathering.The SOE’s notable successes included the destruction of a power station in France, the assassination of Himmler’s deputy Reinhard Heyrich, and ending the Nazi atomic bomb program by destroying the heavy water plant at Vemork, Norway. OSS operatives established anti-Nazi resistance groups across Europe, and managed to smuggle operatives into Nazi Germany, including running one of the war's most important spies, German diplomat Fritz Kolbe.All of their missions were incredibly dangerous and many agents were captured, tortured, and ultimately killed – the life expectancy of an SOE wireless operator in occupied France was just six weeks.In No Moon as Witness, historian James Stejskal examines why these agencies were established, the training regimen and ingenious tools developed to enable agents to undertake their missions, their operational successes, and their legacy.