Whereas many other books concerned with Enigma have concentrated on the work of the cryptanalysts of Bletchley Park this deals with those other people crucial to the effort. The seamen of the Royal Navy, secret agents, Polish cryptanalysts and ironically the Germans.
If you are after the technical details of how Enigma worked and how it was cracked then don't get this book. But if you are interested in reading a gripping account of the events surrounding the Battle for the Code and the consequences thereof then this is a must.
Sebag-Montefiore has compiled outstanding source and reference materials to give the human story behind the code breaking efforts by the British. The bravery of the men of the Royal Navy who risked life and limb to steal codebooks and Enigma machines from German warships and submarines. Also covered are the details of the steps that the Germans took to "secure" their code that often backfired making it easier to break and the incompetance of some German radio operators that also compromised security.