"Stephenson saw such an early-warning system as a co-ordinates intelligence service. Admiral Blinker Hall was the man who might accomplish it. Hall was now Churchill's personal intelligence chief. But Churchill's political fortunes were in decline. There was no British intelligence service faintly resembling those intriguing versions of popular fiction. Instead, there were a few undervalued professionals and some amateurs who began to arrange themselves around Stephenson. And there was the small underpaid, overworked, and ill-appreciated British Secret Intelligence Service, which commanded official recognition and little else." (Chapter 2, pg. 18)

"This knowledge would prove as valuable as the discovery that the new portable Enigma was very different from the original. the machine had a keyboard like a typewriter. The keys were linked electrically through a system of drums. The relationship between the drums could be changed swiftly in a multitude of ways. The sender of a message would hit the...