Magic being a branch of pure mathematics, and computers being machines that can be used to perform lots of mathematical tasks very fast, it follows that most real practicing magicians start out as computer science graduates. The Laundry, the government agency for handling this stuff, started out as a by-blow of the Second World War code-breakers at Bletchley Park, the people who built the first working programmable computers. And the domestic side of our work-preventing accidental incursions by incomprehensible horrors from beyond spacetime-has been growing rapidly in recent decades. You may have noticed there are more computers around these days, and more computer programmers. Guess what? That means more work for the Laundry!

I have a somewhat embarrassing relationship with Wolverhampton. Back when I was at university in Birmingham I nearly landscaped it by accident. I was trying to develop a new graphics algorithm. Planar homogeneous matrix transformations into dimensions dominated by gibbering horrors tend to attract the Laundry’s attention: they got to me just in time-just before the nameless horrors I was about to unintentionally summon into this world-and made me a job offer I wasn’t allowed to refuse.

(Mo’s history is similar-indeed, I was involved not only in recruiting her, but in keeping her alive until she could be recruited. That was some years ago. Mo and I have been together for, oh, about six years; we tied the knot nearly three years ago, using the urgent need to break a behavioral geas as an excuse to do something we both wanted to do anyway.)

So, I’m here at RAF Cosford, an active air force base which is also home to the Royal Air Force Museum annex, where they keep the stuff that’s too big to fit in their North London site at Duxford. Ostensibly I’m here to examine an aircraft that has been the locus of some disturbing incidents (and to stop those incidents recurring). Also, thanks to Angleton, I’m supposed to take a look at something in Hangar Six.

One of the things you learn fairly fast in the Laundry is that most people in the British civil service and armed forces don’t know you exist. You-your organization, your job, the field you work in-are classified so deeply that the mere knowledge that such a classification level exists is itself a state secret. So, to help me do my job, I carry something that we laughably call a “warrant card.” It’s a form of identification. It comes with certain Powers attached. When you present your warrant card for inspection, in the course of official business, the recipients tend to believe you are who and what you say you are, for the duration of that business. Not only that: you can bind them to silence. Of course, trying to use your card outside official business tends to attract the attention of the Auditors. And having attracted their attention once or twice, I’ve never been too keen on finding out what happens next…

The RAF Museum is fronted by a shiny new glass-and-steel aircraft hangar of an exhibit hall. I march right up to the front desk (there’s no queue), present my warrant card, and say: “Bob Howard. I’m here to see Mr. Hastings.”

The wooly headed volunteer behind the cash register puts down her knitting and peers up at me over the rim of her bifocals. “Admission is five pounds,” she chirps.

“I’m here to see Mr. Hastings.” I force a smile and adjust my grip on the warrant card.

“Is that a season pass?” She looks confused.

What? I shove the card under her nose. “I have an appointment with Warrant Officer Hastings,” I repeat, trying to keep a note of impatience out of my voice. “I’m from the Department of Administrative Affairs.” It’s a thin bluff-jeans and tee shirt aren’t normal office attire for the civil service, even in this weather-but I’m crossing the fingers of my free hand and trusting my card to untangle enough of her neurons to get the message across. “A meeting to discuss the, ah, business in Hangar Six.”

She blinks rapidly. “Ooh, Hangar Six! That’s a bad job, it hasn’t been the same since Norman had his Health and Safety inspection… They used to keep the Whirlwind in there, did you know? You’re wanting Geoffrey, aren’t you?”

“Would that be Warrant Officer Hastings?” I ask, hopefully.

“Oh yes.” She pushes her knitting aside with one liver-spotted hand and picks up the telephone with another. “Geoffrey? Geoffrey? There’s a man here to see you! Who did you say you were? A Mr. Howarth! Yes, to see you now! He’s out front!” She puts the phone down. “Geoffrey will be here in a couple of minutes,” she confides, “he needs to scrub up first.”

I tap my toes and whistle tunelessly as I look around the entrance hall. There’s something casting a weird shadow overhead; I look up, and find myself staring at the bulging ventral fuel tank of an English Electric Lightning interceptor, dangling from the ceiling like a demented model-maker’s pride and joy. It’s enough to stop the foot tapping for a moment-if the cable fails, I’ll be squashed like a bug-but a moment’s consideration tells me that it’s highly unlikely. So I stare wistfully at the Lightning for a couple of minutes. Two missiles, sharply raked razor-thin wings, a huge, pregnant belly full of fuel, and the two screamingly powerful engines that once rammed it from a cold start to a thousand miles per hour in under a minute. Life would be so much simpler if our adversaries could be dealt with by supersonic death on the wing-but alas, Human Resources aren’t so easily defeated.

“Mr. Hogarth?”

I turn round. There’s a bluff-looking middle-aged man in blue overalls standing by the front desk: sandy receding hair, a gingery regulation mustache, and a face creased with questions. I hold up my warrant card. “Mr. Howard,” I say. “Capital Laundry Services. I believe you asked for a visit.”

He does a visible double take. “Eh, yes, I did-” He’s clocking the jeans, tee shirt, and casual linen jacket, and I can see the gears whirring in his head as he wonders if I’m some kind of impostor. Then his eyes reach my warrant card and something clicks behind them and he’s slightly less human than he was a moment before-“sir.”

“I was told your problem is in Hangar Six. Why don’t you take me there? You can explain along the way.”

I put the warrant card back in my pocket. No point in frying him.

“If you’d follow me, please, sir.” He has a pronounced borders accent. He turns and opens a door marked AUTHORIZED PERSONNEL ONLY. “Sorry about Helen on the front desk,” he murmurs. “She’s a little slow, but she means well. Only see you, she’s been helping out here since forever, and we run on volunteers.” He shrugs. “I suppose it’s better for her than sitting around an old-age home waiting to die-” He lets the door close behind us before he says anything more. “Bloody rum business, Hangar Six.”

“Tell me about it. In your own words,” I add.

“It’s another of the Lightnings-hull number XR727.” He glances over his shoulder. “It’s been sitting in Hangar Six for years while we were waiting for funding to come through-plan was to restore it for static display in Hall Four when it’s ready. It’s an F. Mark 3, upgraded from F.2A like the one over the front desk.” I’ll take his word for it: I’m not au fait with the model numbers. “We’ve had a few odd incidents.”

Odd incidents? “Define odd.”

“Frosty patches on the hangar floor, mysterious oil leaks-under hydraulic pipes that were drained more than twenty years ago when it was taken out of service-nothing really unusual, seeing where it came from, if you follow my drift. But then there was the business with Marcia and the instrument panel, and I thought it might be a good idea to call you chappies directly.”

Clunk. A domino slips into place in my mental map. This enquiry didn’t come through the RAF, this came direct from Hastings. “You’ve worked with us before.”

“Not exactly…” He pauses beside an anonymous door, and extracts a fat key chain: “But I was with the Squadron, on ground crew. Once you’re in, you never really leave.” Click. “They like to stay in touch.”