Tools of the covert trade:

Left: an example of the German Enigma cipher machine.

Right: A set of acetone time-fuses, a camera disguised as a matchbox, and a secret map hidden inside a playing card.

Spy stories have become cliched to the point of comedy in the past few years, while spy organizations like the CIA alternate between being the butt of vicious jokes and the bad guys in wacky conspiracy theories. It's easy to forget that once upon a time, spy stories were not fiction, and covert operations were a deadly serious matter, with many lives riding on the outcome. But such a time really existed. In fact, it's not an exaggeration to say that without covert operations, the Allies might not have won World War 2.