SOMETIMES a secret sits like a mothball hidden in a drawer, dissolving in time until there is nothing left at all. My mother-in-law, Joan Turnour, had such a secret relating to her work in World War II, and it might have gone that way but for a package arriving out of the blue last month. The package contained a special medal and certificate signed by British Prime Minister David Cameron, plus a letter from Iain Lobban, the head of Britain's highly secretive intelligence agency known as GCHQ. This recognition might be nearly 70 years after her wartime deeds, but for 40 of those years she wasn't even able to talk about them.
Joan's work was not in the jungles of New Guinea nor in London during the Blitz; it was in a long-since-demolished building in Albert Park known as ''Monterey Flats''. She was involved in cracking the codes used by the Japanese to try to ensure their battle plans gave them the advantage of surprise. The efforts of people who cracked those codes, and then were able to keep the cracking a secret, have since been credited with shortening the war by years. ''We were not even able to tell our families,'' says Joan, now 85. ''When anyone asked, we just said we worked as a writer. They thought we were secretaries or something.''
Such was the secrecy that each person in a section was entrusted with just a small piece of the jigsaw. ''We were presented with what looked like a jumble of letters and numbers and we spent our shift sorting them into some sort of order, which was the raw code that was then passed on to the next section. ''If there was a flap on, such as the Japanese moving their ships, they would virtually pull it out of your hands and run down the corridor.'' The total jigsaw was known only by a handful at the very top and this knowledge was considered so vital that in the upper echelon's offices there was said to be a cupboard containing pistols.
They were not for self-defence. Most at Joan's level believed if Australia was invaded and there was a chance those with the full picture were captured, they were to be shot. ''We came to understand that the seniors were not to fall into enemy hands. The story about them having to be shot was hearsay, but we believed it.'' When she told her family this story and how the shooting would be accepted without question, it left us in shock and seemed to highlight how much society's values had changed in less than a lifetime.
Lobban's letter referred to the cryptanalysts who worked with British, other Commonwealth and US agents as the ''Forgotten Army'' of the war. Joan's section was considered an outpost of Bletchley Park, the highly secret British code-breaking centre near Cambridge University where the German Enigma code was cracked.
But sometimes security could be breached with the best intentions. Joan recounts a US senator visiting Australian intelligence bases at the time, who then went back home and told newspapers how American ingenuity had cracked the Japanese codes. ''Of course, the Japanese immediately changed their codes and it took us about three weeks to unravel the new ones. This breach probably cost lives.''