I picked up this book in a sale, by random chance, and am so glad that I did. Rory Clements has done his homework on the facts of the atom bomb, and gets it across without going into too much detail, just enough for me to understand. The plot is intriguing and the twists and turns kept me glued to my chair and turning the pages. It is easy to read and the plot flows easily. My only one - well, not criticism - just pointing out - there are quite a range of characters, and if I were to read this book in small "bites" at a time, I would lose track of just who was who (especially as some of them turn out not to be what they first seemed to be, as in any good thriller / spy book ) but this could just be me. The range of characters is necessary, as the plot flows seamlessly across England and Germany, with a bit of Switzerland thrown in. You really feel that Rory has done his groundwork on the aeroplanes, for example, and very much on the Cambridge University in the late 1930s. There is a little bit of sex and violence, but this is not unnecessarily focussed, but is incidental to the plot. Love it!