This was very enjoyable and a surprisingly good example of the genre. Speaking to others who have read this but who haven't read a lot of spy novels I got the impression that they thought this was an example of what a good author could do with the genre. Which is frankly ridiculous. There are some fantastic authors who specialise in that genre and this book follows the same formula as a number of the better books by these authors. An innocent gets involved in the spy business for whatever reason and the inevitable results follow.
Of course, in this book, the innocence isn't to do with the spy business. And so this book isn't about espionage and isn't therefore of that genre. The spy business is just a stage for the actual (brilliant) story.