Forget poison-tipped umbrellas and exploding cigars. At the height of the cold war, the CIA issued its top spooks with a more prosaic piece of equipment: a beginner's guide to magic, educating them in the old-fashioned arts of conjuring and sleight-of-hand.
The Official CIA Manual of Trickery and Deception was written in 1953 by a well-known performer named John Mulholland. It included tips for hiding objects up your sleeve, spiking someone's drink (while pretending to light a cigarette) and communicating with colleagues by tying your shoelaces in a special way.
In 1973, as the cold war showed signs of thawing, the CIA ordered every copy of the "top secret" document to be destroyed. But one managed to escape the agency's paper shredders and was recently unearthed, in mysterious circumstances, by the espionage historian, H Keith Melton and Robert Wallace, an author and former CIA staffer.
The pair managed to get the manual declassified and have now turned it into a book with chapters on "the surreptitious removal of objects by women" and making and concealing "droppers" for liquids and powders. There is also a basic protocol for handling several small objects at one time so that one of them will secretly end up in your pocket.
A good magician looks grey and unremarkable, Mulholland advises, saying he "should be so normal in manner, and his actions so natural, that nothing about him excites suspicion". When carrying out a trick, spies should distract their audience by putting on a silly face. "The more facial muscles are relaxed and eyes thrown out of focus, the greater the effect. Doing these actions to a mild degree merely shows a lack of alertness or disinterest."
Some of his advice is basic conjuring lore. A good trick "must be simple in its basic idea" and should be tirelessly "rehearsed" in a mirror. Some is more advanced. He showed how stage magicians use perspective to saw a woman in half, and gave detailed advice on how the various pockets in a normal suit can conceal dozens of objects.
A small blob of wax on the bottom of a hardback book can be used to pick up paper, he writes. A pill concealed in a matchbox can be secretly dropped in someone's drink if you pretend to be lighting their cigarette. A hollowed-out pencil containing powder can be emptied while you pretend to use it to sketch a diagram.
Meanwhile, shoelaces can be used to pass on a range of different messages, depending on the way in which they're tied. A chapter in the book outlines how different knots can mean "I have information", "Follow me" and "I have brought another person".
Mulholland, was a well-known performer who edited magicians' magazine The Sphinx for 23 years and earned the then-princely sum of $3,000 (£1,800) for the book. It was originally published as part of a wider CIA programme known as 'Project Mkultra', which among other things experimented with using LSD to counter advanced Soviet "mind-control" techniques.
In the foreword of the new edition, published by William Morrow, the current deputy CIA director John McLaughlin writes that "magic and espionage are kindred spirits", revealing that "Mulholland's writing on delivery of pills, potions and powders was just one example of research carried out back then in fields as diverse as brainwashing and paranormal psychology".