My journey to the school for spies starts in the half-light of a waking city. I do not know where I am going and have only been instructed to meet my contact at a central London landmark. We travel by car, boat and train to a place where officers of Britain’s Secret Intelligence Service, the overseas espionage agency known as SIS, learn their craft. I am not allowed to describe it to you, but I can tell you this: it is giant and austere and the slicing wind makes my eyes water.
At the door, I am met by a small, cheerful woman with short, wavy blonde hair whose beaming welcome is at odds with the sterile eeriness of this place. Kathy, who is in charge of all intelligence operations by SIS officers and their agents around the world, ushers me over to a bank of armchairs next to a large window overlooking a paved landscape.