Stephen Twigge & The National Archives 
Spy Toolkit [PDF ebook] 
Extraordinary inventions from World War II

A revealing, sometimes sinister and often hilarious look at the gadgets and devices devised to help spies in their profession.Spies claim that theirs is the second oldest profession. Secret agents across time have had the same key tasks: looking and listening, getting the information they need and smuggling it back home. Over the course of human history, some amazingly complex and imaginative tools have been created to help those working under the cloak of supreme secrecy.During the Second World War, British undercover agents were the heroes behind the scenes, playing a dangerous and sometimes deadly game risking all to gather intelligence about their enemies. What did these agents have in their toolkits? What ingenious spy gadgets did they have up their sleeves? What devious tricks did they deploy to avoid detection?From the ingenious to the amusing, this highly visual book delves into espionage files that were long held top secret, revealing spycraft in action.