A fascinating real story about Elizebeth Friedman, who many consider the "mother of modern cryptoanalysis and cryptography." Her contributions during WWI and WWII were tremendous, but are largely unknown, primarily because she is remembered as the wife of William Friedman, who also was a brilliant cryptanalyst.

The book is full of colorful characters, not least among them "Colonel" George Fabyan, an eccentric millionaire who sponsored a lot of research on both worthwhile and dubious enterprises at his Riverbank estate, which is where William and Elizebeth met and honed their skills.

Elizebeth was pivotal in America's efforts to defeat the Nazis and the Japanese, by creating the infrastructure which decoded a large percentage of the encrypted messages being used by America's adversaries, at a time before computers were available to perform this task. Unfortunately Elizebeth's contributions have been downplayed for far too long.

The book reads like a whodunit and doesn't disappoint.