They're now legendary: The code-breakers of England's Bletchley Park, who eavesdropped on Germany all through World War II to D-Day and the fall of Berlin.
Ten thousand mathematicians, crossword puzzle enthusiasts and linguists, who get credit for shortening that war by two years, worked at Bletchley Park, mostly Brits and some Americans. One surviving code breaker described them as a very odd selection of people.
"Everything was quite mad, really," says Mavis Batey, who worked as a decoder.
The 87-year-old Batey decoded a message revealing the date of a planned Italian naval attack. Forewarned, the British were ready, and the Italian navy was crushed.
"Probably the most fantastic line that anybody had seen," Batey says.
Many successes were the result of the capture of "Enigma," the Germans' encoding machine.
"This machine has 158 million different options," says Simon Greenish, director of Bletchley Park.
Armed with the code books captured with the machine, the people at Bletchley Park were able to give the British-American allies an extraordinary insight into the Nazis' battle plans.
Now, it's time that is winning the battle at Bletchley Park.
"This hut is where the process of code-breaking went from a cottage industry into an industrial process," Greenish says.
The buildings, where thousands of messages were decoded daily, are falling down. They estimate it will take $15 million to save them.
Salvage work so far has been a labor of love, like the 14-year rebuild of Colossus, a top-secret computer that could break the cipher used by the German high command, and still works as fast as a laptop.
It wasn't all about code breaking, though. Batey met her husband Keith at Bletchley Park. Theirs was one of many romances, but the work was so secret that for decades until it was declassified, even husbands and wives didn't talk about what they did, MacVicar reports.
But their work is considered important enough that it needs to be saved before it all fades from memory.