This book is obviously the result of meticulous research, and to those who are interested in how the various hidden elements of WWII fit together - Frank Foley was involved in interrogating Hess, and mention is made of various other people and projects which were top secret at the time - this is a good resource. But for those readers who are drawn in by the extravagant byline of "How British intelligence broke Hitler's deputy", a disappointment awaits. The truth is, Hess was a deluded hero worshipper with no authority to broker a deal, and he was disowned by the German High Command as soon as it was known he had been captured by the British.
The British got no useful strategic material from him - because he didn't know anything - and no useful intelligence because, again, he didn't know anything, and also didn't seem interested in knowing it. McGinty draws this out for a long period of time, mirroring the lengths that the interrogators went to in order to try to draw out as much from Hess as they could, but ultimately their quest, like this book, promised much but delivered little.
On a side note, McGinty writes well and knows his stuff; if the book feels drawn out sometimes, that's because there is no pay-off and this can be a bit frustrating sometimes. But the story is worth telling, if only to confirm that not much happened, and for historical WWII enthusiasts this book will definitely fill in this episode quite well. For those just looking for an interesting and true story though, give this a miss. There were many more well documented WWII stories available that will satisfy far more than this will.