The book tells about an unprecedented penetration into the enemy's plans in military history: the cracking of the German Enigma machine cipher by the Western allies in the anti-Hitler coalition. Until recently, the most important aspect of this event remained unclear: was the role that codebreakers played in achieving victory over Germany during World War II really so significant? The book also talks about the role of special operations in capturing key installations for Enigma, the betrayal of a high-ranking employee of the German encryption service and the numerous miscalculations of the Germans themselves.