There have been many histories of Bletchley Park and the heroic work of Alan Turing and the code-breakers, work so important that it changed the course of the Second World War, shortening it by two years. This book tells a different story, of how this intensely iconic historical site was saved using the power of social media and the very computing technology that was born here. When Dr Sue Black first visited Bletchley in 2004, her preconception was that it had been run by a small group of tweed-jacketed, pipe-smoking men. To her surprise she discovered that ten thousand people worked there during the war, that half of them were women, and that most were in their late teens and twenties. As a woman in computer science herself, she was hugely inspired by their stories. When she discovered that Bletchley was under threat of closure due to lack of funding, she set about a campaign to transform it into the heritage site it deserved to be. Harnessing the pride and inside knowledge of the surviving code-breakers, the power of Twitter, plus the reach of the modern broadcast and online media, Sue Black's campaign brought together thousands of supporters, from all walks of life, from celebrity supporters like Stephen Fry to the veterans, enthusiasts and computer geeks who offered their time and passion to save this extraordinary place. This is a wholly inspiring story of community-building, and how the determination of committed people can stop one of our most significant historical treasures being swept away by the bulldozers.