“Can you handle a mop and bucket?” asks Lockhart.

“I don’t know. Can you impersonate a bank manager?” I fire back (which is unkind and unfair because he always dresses the part).

He looks at me with ill-concealed distaste. “We’ve sorted you out a way in,” he says. “They’re couriering a uniform over here right now. You’re down on the roster as Sara Siad’s replacement on this evening’s shift; Sara’s supervisor, Eva Kadir, can show you where Mrs. Siad’s body was found. Just try not to mess things up.”

“What else?” I ask.

“You’ll be wearing a wire and the OCCULUS brick outside will be monitoring the feed from their truck. In event of trouble you’ll have two extraction paths: one is via the police—we’ll have our liaison in SCO1 ready to dispatch a team to ‘arrest’ you if you get into trouble, and they’ll be pre-briefed that you’re doing a black bag job for SIS. The other is the OCCULUS team themselves, but . . . we don’t want to do that. Do you understand?”

I nod soberly. An OCCULUS extraction in Docklands would be visible all the way from six different TV studios and a couple of newspaper newsrooms. Nobody wants to be the subject matter of a COBRA briefing to the Prime Minister and cabinet, due to the tower of smoke rising to the east of Downing Street: that kind of thing can be a career-limiting move, especially if the existence of the organization you work for is a state secret the PM hasn’t been cleared for. So the availability of a full OCCULUS team outside the bank HQ isn’t about rescuing my sorry ass if I run into something I can’t handle: it’s about saving London if it turns out there’s the thaumaturgic equivalent of a nuke in the basement.

“Okay, I’d better go visit Harry,” I say. “Page me when the G4S package arrives.”

Harry the Horse is our in-house armorer. One-eyed, with a manner he acquired from studying The Long Good Friday, he’s an ex-cop or ex-soldier or ex-something that allowed him to acquire an alarming amount of expertise about killing people in the course of his profession. He hangs out in a cubbyhole in the basement, with a walk-in gun safe and a firing range.*

“’Ello, my son,” he says as I stick my head round the door. “What brings you down here today?”

“A Code Blue,” I say, which gets his attention instantly. “I’ve got to go poke my nose around an office this evening. Police and OCCULUS backup outside, but it’s a low-key investigation: we don’t want to attract attention. So I need arms and armor for self-defense, but nothing I can’t conceal inside a cleaner’s overall.”