She looks around with green eyes as deep as sacrificial cenotes, eyes in which a sensitive witness might see luminous worms writhing. But there are no sensitive witnesses to see through the glamour: just the ordinary post-work crowd hurrying about their business on the London streets. For a moment her face shimmers, the facade sliding—her attention is strained, flying in too many directions to maintain the illusion effectively—but then she notices and pulls herself together. She returns the chilly pistol to her bag. Then, turning on one spiked heel, she strides away from the corpse: just another professional woman on her way home from the office. Nobody has witnessed the killing, and it will be twenty minutes before a passing policeman realizes that the drunk sleeping in the doorway is never going to rise again.

7. Beer and tea

YOU CAN FOCUS ON THINKING YOURSELF INTO THE OTHER guy's shoes until the cows come home, but it's not going to do you a whole lot of good if he's actually wearing sandals. More to the point, what if he's got an entire shoe rack to choose from, and the pair you need is the one that's missing? There is a chicken-and-egg problem here, or more accurately a sole-and-bootstrap one, and I'm not going to solve it by sitting in my office. Nor am I going to fix matters by hollering down the speaking tube at the gnomes buried in the stacks, not with just two delivery runs a day.

On the other hand, if you go and actually look at the other guy's footprints you might just find something new. And so, in a spirit of enquiry, I set out to burgle Angleton's office.

Now, it just so happens that Angleton has officially been declared missing. And I am his assistant trainee tea-boy. In a more paranoid working environment I might just be under suspicion of having disappeared him myself: perish the thought and pass the ammunition. But Angleton is reckoned to be sufficiently formidable that . . . well, let's say it's unlikely. Besides, we don't generally play politics with the kid gloves off. (There are exceptions, such as the late and unlamented Bridget; but they're exactly that: exceptions. The hard fact is that all the real players can turn the game board into a smoking hole in the map. Which generally forces them to tread lightly.)

Skulking past Iris's office window, I tiptoe around the coffee station and duck down the back staircase, through the fire doors, round the bend, down the fire escape stairs, and then pause outside the unmarked green metal door. I do not encounter anyone in the process, but you can never be sure—there are cameras, and there is Internal Security, and if you're really unlucky there are the caretakers from the night shift. This is a security agency after all. However slipshod and dustily eccentric it might appear at times, you should never take things for granted if you are perpetrating monkey business.