In the 1950s, the CIA hired professional magician John Mulholland to teach intelligence officers something stage magicians already understood very well: how to make people look in the wrong place.

Mulholland was a respected New York magician and former editor of The Sphinx, one of the leading magic magazines of its day. The CIA believed that techniques used to fool an audience could also be useful in espionage.

He produced two secret training manuals explaining how agents could use sleight of hand, misdirection, concealment and carefully choreographed movements in the field.

One technique was the brush pass, in which two people walking past each other secretly exchange an object. A larger, perfectly ordinary movement, such as checking a watch or shifting a coat, attracts the eye while the other hand makes the transfer. The technique came directly from the world of magic.

Mulholland also advised the CIA on covert signals, hidden objects and ways of making clandestine actions appear completely ordinary. His work extended into the CIA's controversial MKULTRA program, including methods for secretly introducing substances into food or drinks.

Most of the MKULTRA records were ordered destroyed in 1973, and Mulholland's manuals were believed lost. Then, in 2007, former CIA technical-services director Robert Wallace found references to them and eventually located surviving copies.

The manuals revealed that some classic spycraft owed less to futuristic gadgets than to an art practiced for centuries on theater stages: getting someone to watch exactly what you want them to watch while something else happens nearby.

Photo of Audrey Hepburn in the classic spy film Charade