I really wanted to enjoy this book as I really liked the cover and blurb. I have just had to conclude, though, that it really wasn’t for me at all. Perhaps it was because this is the fourth in a series of books so I wasn’t able to appreciate all the back story and understand all the complex relationships etc. It’s a boy’s own style story of spies and secret agents (rather than the literal battle fields) that follows a Cambridge professor as he accepts a top secret mission to rescue a parcel that might just bring peace. I was able to guess the ‘secret’ pretty quickly, but carried on reading till the end, just I absolutely appreciate that the levels of historical research are impressive as the book evokes much of the horror of Hitler’s regime, complete with its toxic internal rivalries, effectively. It just didn't grip me.