I struggled through this book all the way to page 192 of 322 where Fasson and Grazier were "posthumously awarded the Victoria Cross" for recovering the enigma machine from U-559. At this point I took the book outside and set fire to it. I did not find Fasson and Grazier on any list of V.C. recipients (the reason for that is that they were awarded the George Cross) and that indicates a level of basic fact checking that has not been applied to this book. That's unfair of me I know, this book is a general history aimed at the general reader so quite why Mr Sinclair writes on page 39 about how excited the academic world was about Mr. Knox's discovery and how it was "as if Aristotle's Second Book of Poetics had been found." Well as a general reader I didn't know that Aristotle had written a second book of poetics even less that the careless fool had lost it. Titillation/speculation about Mr. Knox selecting nubile society fillies to work in his stable got boring in the first chapter but it's mentioned again at the end of chapter 6 then that's contrasted with "the possibility that Knox had somehow found that women had greater aptitude ....". Somehow? Somehow? Perhaps it's escaped Mr Sinclair that there was a war taking place and that by and large the men were off fighting it?
Unfortunately, I had to give this book one star as you can't review it with 0 stars. 1 star would indicate it has some merit. It has none.
If you want the technical story of Bletchley Park you might enjoy: Colossus: The secrets of Bletchley Park's code-breaking computers
or if you want to read about the incredible strategic influence the work of those at Bletchley then F.W. Winterbotham's The Ultra Secret: The Inside Story of Operation Ultra, Bletchley Park and Enigma