Spying is supposedly the second oldest profession, and the smoke and mirror world has inspired countless authors and films of this world where no one can trust anyone else. In this brave new digital world, gone are a lot of the old techniques and tradecraft, instead, the spooks are sifting our mind-boggling quantities of data looking for the ghosts in the machines. Except they aren’t always there. However, having a human perspective on the world around you is still an advantage. An expert operative who can determine the wheat from the digital chaff is still invaluable and in this book, Grey, takes us on some of the nail-biting missions and how having the right person in the right place at the most appropriate moment is still the way to win against enemies real and virtual.

Grey also considers where espionage is heading too. The ability of modern agencies to hoover up vast amounts of data from every phone call, web page and email means that they are drowning in data, so much so that they do miss things. Gone are the days when these was state verses state with fairly clear, if blurred lines and long term goals that could be met. Now it is state verses small cells of a disparate organisation that do things very differently and modern spies may have missions that only last a few months. But still the key is still using human judgement that draws from intelligence from people on the ground, proper analysed signals intelligence along with other elements and combining them to form the best picture of what is happening. Overall an interesting book about a sector that still likes to hide in the shadows. ( )