"Isn't it supposed to be leakproof, by definition?"

"I'm getting to that. Be patient, Bob." There's a waspish note in his voice, and I shut up hastily.

A minute later, Angleton pulls a mimeographed booklet from the file and closes the lid. He returns to the desk, and slides the booklet toward me.

"I think you'd better read this first, then go and do what Andy wants," he says slowly. "Be a good boy and copy me on your detailed itinerary before you depart."

I read the cover of the booklet, which is dog-eared and dusty. There's a picture of a swell guy in a suit and a gal in a fifties beehive hairdo sitting in front of a piece of industrial archaeology. The title reads: POWER, COOLING, AND SUBSTATION REQUIREMENTS FOR YOUR IBMS/1602-M200. I sneeze, puzzled. "Boss?"

"I suggest you read and memorize this booklet, Bob. It is not impossible that there will be an exam, and you really wouldn't want to fail it."

My skin crawls. "Boss?"

Pause.

"It's not true that the Funny Farm is entirely leakproof, Bob. It's surrounded by an air-gap, but it was designed to leak under certain very specific conditions. I find it troubling that these conditions do not appear to apply to the present circumstances. In addition to memorizing this document, you might want to review the files on GIBBOUS MOON and AXIOM REFUGE before you go." Pause. Pause. "And if you see Cantor, give my regards to the old coffin-dodger. I'm "And if you see Cantor, give my regards to the old coffin-dodger. I'm particularly particularly interested in hearing what he's been up to for the past thirty years . . ." interested in hearing what he's been up to for the past thirty years . . ."

Renfield takes me back to the smoking room and shuts the door. "He's having a bad day, I'm afraid." She pulls out a cardboard packet and extracts a cigarette. "Smoke?"

"Uh, no thanks." The sash windows are nailed shut and their frames painted over. There's a louvered vent near the top of the windows, grossly unfit for the purpose: I try not to breathe too deeply. "What happened to him?"

She strikes a match and contemplates the flame for a moment. "Let's see. He's forty-two. Married, two kids-he talks about them. Wife's a schoolteacher, his deep cover is that he works in MI6 clerical." (You're not supposed to talk about your work to your partner, but it's difficult enough that we've been given dispensation to tell little white lies-and if necessary, HR will back them up.) "He's not field-qualified-mostly he does theory-but he worked for Q Division, and he was on secondment to the Abstract Attractor Working Group when he fell ill."

In other words, he's a theoretical thaumaturgist. Magic being a branch of applied mathematics, when you carry out certain computational operations, it has echoes in the Platonic realm of pure mathematics-echoes audible to beings whose true nature I cannot speak of, on account of doing so being a violation of the Official Secrets Act. Theoretical thaumaturgists are the guys who develop new efferent algorithms (or, colloquially, "spells"): it's an occupation with a high attrition rate.

"He's convinced the Auditors are after him for thinking inappropriate thoughts on organization time. There's an elaborate confabulation, and it looks a little like paranoid schizophrenia at first glance, but underneath . . . We sent him to our Trust hospital for an MRI scan, and he's got the characteristic lesions."

"Lesions?"

She takes a deep drag from the cigarette. "His prefrontal lobes look like Swiss cheese. It's one of the early signs of Krantzberg Syndrome. If we can keep him isolated from work for a couple more months, then retire him to a nice quiet desk job, we might be able to stabilize him. K. Syndrome's not like Alzheimer's: if you remove the insult, it frequently goes into remission. Mind you, he may also need a course of chemotherapy. At various times my predecessors tried electroconvulsive treatment, prefrontal lobotomy, neuroleptics, daytime television, LSD-none of them work consistently or reliably. The best treatment still seems to be bed rest followed by work therapy in a quiet, undemanding office environment." Blue cloud spirals toward the ceiling. "But he'll never run a great summoning again."

I'm beginning to regret not accepting her offer of a cigarette, and I don't even smoke. My mouth's dry. I sit down: "Do we have any idea what causes K. Syndrome?" I've skimmed GIBBOUS MOON, but the medical jargon didn't mean much to me; and AXIOM REFUGE was even less helpful. (It turned out to be a dense mathematical treatise introducing a notation for describing certain categories of topological defect in a twelve-dimensional space.) Only the power supply for the mainframe-presumably the one Matron uses-seems remotely relevant to the job in hand.

"There are several theories." Renfield twitches ash on the threadbare carpet as she paces the room. "It tends to hit theoretical computational demonologists after about twenty years: Merriweather is unusually young. It also hits people who've worked in high-thaum fields for too long. Initial symptoms include mild ataxia-you saw his hand shaking?-and heightened affect: it can be mistaken for bipolar disorder or hyperactivity. There's also the disordered thinking and auditory hallucinations typical of some types of schizophrenia." She pauses to inhale. "There are two schools of thought, if you leave out the Malleus Maleficarum Malleus Maleficarum stuff about souls contaminated by demonic effusions: one is that exposure to high-thaum fields causes progressive brain lesions. Trouble is, it's rare enough that we haven't been able to quantify that, and-" stuff about souls contaminated by demonic effusions: one is that exposure to high-thaum fields causes progressive brain lesions. Trouble is, it's rare enough that we haven't been able to quantify that, and-"

"The other theory?" I prod.

"My favorite." She nearly smiles. "Computational demonology-you carry out calculations, you prove theorems; somewhere else in the Platonic realm of mathematics Listeners notice your activities and respond, yes? Well, there's some disagreement over this, but the current orthodoxy in neurophysiology is that the human brain is a computational organ. We can carry out computational tasks, yes? We're not very good at it, and at an individual neurological level there's no mechanism that might invoke the core Turing theorems, but . . . if you think too hard about certain problems, you might run the risk of carrying out a minor summoning in your own head. Nothing big enough or bad enough to get out, but . . . those florid daydreams? And the sick feeling afterward because you can't quite remember what it was about? Something in another universe just sucked a microscopic lump of neural tissue right out of your intrapa rietal sulcus, and it won't grow back."

Urk. Not so much "use it or lose it" as "use it Not so much "use it or lose it" as "use it and and lose it," then. Could be worse, could be a NAND gate in there . . . "Do we know why some people suffer from it and others don't?" lose it," then. Could be worse, could be a NAND gate in there . . . "Do we know why some people suffer from it and others don't?"

"No idea." She drops what's left of her cigarette and grinds it under the heel of a sensible shoe. She catches my eye. "Don't worry about it, the Sisters keep everything orderly," she says. "Do you know what you want to do next?"

"Yes," I say, damning myself for a fool before I take the next logical step: "I want to talk to the long-term inmates."

I'm half-hoping Renfield will put her foot down and refuse point-blank to let me do it, but she only puts up a token fight: she makes me sign a personal-injury-claims waiver and scribble out a written order instructing her to show me the gallery. So why do I feel as if I've somehow been outmaneuvered?

After I finish signing forms to her heart's content, she uncaps an ancient and battered speaking tube beside her desk and calls down it. "Matron, I am taking the inspector to see the observation gallery, in accordance with orders from Head Office. He will then meet with the inmates in Ward Two. We may be some time." She screws the cap back on before turning to me apologetically. "It's vital to keep Matron informed of our movements; otherwise, she might mistake them for an escape attempt and take appropriate action."

I swallow. "Does that happen often?" I ask, as she opens the office door and stalks toward the corridor at the other end.

"Once in a while a temporary patient gets stir-crazy." She starts up the stairs. "But the long-term residents . . . No, not so much."

Upstairs, there's a landing very similar to the one we just left-with one big exception: a narrow, white-painted metal door in one wall, stark and raw, secured by a shiny brass padlock and a set of wards so ugly and powerful that they make my skin crawl. There are no narrow-gauge rails leading under this door, no obvious conductive surfaces, nothing to act as a conduit for occult forces. Renfield fumbles with a huge key ring at her side, then unfastens the padlock. "This is the way in via the observation gallery," she says. "There are a couple of things to bear in mind. Firstly, the Nurses can't guarantee your safety: if you get in trouble with the prisoners, you're on your own. Secondly, the gallery is a Faraday cage, and it's thauma turgically grounded too-it'd take a black mass and a multiple sacrifice to get anything going in here. You can observe the apartments via the periscopes and hearing tubes provided. That's our preferred way-you can go into the ward by proceeding to the other end of the gallery, but I'd be very grateful if you could refrain from doing so unless it's absolutely essential. They're difficult enough to manage as it is. Finally, if you insist on meeting them, just try to remember that appearances can be deceptive."

"They're not demented," she adds, "just extremely dangerous. And not in a Hannibal Lecter bite-your-throat-out sense. They-the long-term residents-aren't regular Krantzberg Syndrome cases. They're stable and communicative, but . . . You'll see for yourself."

I change the subject before she can scare me any more. "How do I get into the ward proper? And how do I leave?"

"You go down the stairs at the far end of the gallery. There's a short corridor with a door at each end. The doors are interlocked so that only one can be open at a time. The outer door will lock automatically behind you when it closes, and it can only be unlocked from a control panel at this end of the viewing gallery. Someone up here"-meaning, Renfield herself-"has to let you out." We reach the first periscope station in the viewing gallery. "This is room two. It's currently occupied by Alan Turing." She notices my start. "Don't worry. It's just his safety name."

(True names have power, so the Laundry is big on call by reference, not call by value; I'm no more "Bob Howard" than the "Alan Turing" in room two is the father of computer science and applied computational demonology.) She continues. "The real Alan Turing would be nearly a hundred by now. All our long-term residents are named for famous mathematicians. We've got Alan Turing, Kurt Godel, Georg Cantor, and Benoit Mandelbrot. Turing's the oldest, Benny is the most recent-he actually has a payroll number, sixteen."

I'm in five digits-I don't know whether to laugh or cry. "Who's the nameless one?" I ask.

"That would be Georg Cantor," she says slowly. "He's probably in room four."

I bend over the indicated periscope, remove the brass cap, and peer into the alien world of the nameless K. Syndrome survivor.

I see a whitewashed room, quite spacious, with a toilet area off to one side and a bedroom accessible through a doorless opening-much like the short-term ward. The same recessed metal tracks run around the floor, so that a Nurse can reach every spot in the apartment. There's the usual comfortable, slightly shabby furniture, a pile of newspapers at one side of the sofa and a sideboard with a windup gramophone. In the middle of the floor there's a table, and two chairs. Two men sit on either side of an ancient travel chess set, leaning over a game that's clearly in its later stages. They're both old, although how old isn't immediately obvious-one has gone bald, and his liver-spotted pate reminds me of an ancient tortoise, but the other still has a full head of white hair and an impressive (but neatly trimmed) beard. They're wearing polo shirts and grey suits of a kind that went out of fashion with the fall of the Soviet Union. I'm willing to bet there are no laces in their brogues.

The guy with the hair makes a move, and I squint through the periscope. That was wrong, wasn't it? That was wrong, wasn't it? I realize, trying to work out what's happening. I realize, trying to work out what's happening. Knights don't move like that. Knights don't move like that. Then the implication of something Angleton said back in the office sinks in, and an icy sweat prickles in the small of my back. "Do you play chess?" I ask Dr. Renfield without looking round. Then the implication of something Angleton said back in the office sinks in, and an icy sweat prickles in the small of my back. "Do you play chess?" I ask Dr. Renfield without looking round.

"No." She sounds disinterested. "It's one of the safe games-no dice, no need for a pencil and paper. And it seems to be helpful. Why?"

"Nothing, I hope." But my hopes are dashed a moment later when turtle-head responds with a sideways flick of a pawn, two squares to the left, and takes beardy's knight. Turtle-head drops the knight into a biscuit tin along with the other disused pieces; it sticks to the side, as if magnetized. Beardy nods, as if pleased, then leans back and glances up.

I recoil from the periscope a moment before I meet his eyes. "The two players. Guy like a tortoise, and another with a white beard and a full head of hair. They are . . . ?"

"That'd be Turing and Cantor. Turing used to be a Detached Special Secretary in Ops, I think; we're not sure who or what Cantor was, but he was someone senior." I try not to twitch. DSS is one of those those grades, the fuzzy ones that HR aren't allowed to get their grubby little fingers on. I think Angleton's one. (Scuttlebutt is that it's an acronym for Deeply Scary Sorcerer.) "They play chess every afternoon for a couple of hours-for as long as I can remember." grades, the fuzzy ones that HR aren't allowed to get their grubby little fingers on. I think Angleton's one. (Scuttlebutt is that it's an acronym for Deeply Scary Sorcerer.) "They play chess every afternoon for a couple of hours-for as long as I can remember."

Right. I peer down the periscope again, looking at the game of not-chess. "Tell me about Dr. Hexenhammer. Where is he?"

"Julius? I think he's in an off-site meeting or something today," she says vaguely. "Why?"

"Just wondering. How long has he been working here?"

"Before my time." She pauses. "About thirty years, I think."

Oh dear. "He doesn't play chess either," I speculate, as Cantor's king makes a knight's move and Turing's queen's pawn beats a hasty retreat. A nasty suspicious thought strikes me-about Renfield, not the inmates. "Tell me, do Cantor and Turing play chess regularly?" I straighten up.

"Every afternoon for a couple of hours. Julius says they've been doing it for as long as he can remember. It seems to be good for them." I look at her sharply. Her expression is vacant: wide-awake but nobody home. The hairs on the back of my neck begin to prickle.

Right. I am getting a very very bad feeling about this. "I need to go and talk to the patients now. In person." I stand up and hook the cap back over the periscope. "Stick around for fifteen minutes, please, in case I need to leave in a hurry. Otherwise"-I glance at my watch-"it's twenty past one. Check back for me every hour on the half hour." bad feeling about this. "I need to go and talk to the patients now. In person." I stand up and hook the cap back over the periscope. "Stick around for fifteen minutes, please, in case I need to leave in a hurry. Otherwise"-I glance at my watch-"it's twenty past one. Check back for me every hour on the half hour."

"Are you certain you need to do this?" Her eyes narrow, suddenly alert once more.

"You visit with the patients, don't you?" I raise an eyebrow. "And you do it on your own, with Dr. Hexenhammer up here to let you out if there's a problem. And the Sisters."

"Yes, but-" She bites her tongue.

"Yes?" I give her the long stare.

"I'm rubbish with computers!" she bursts out. "But you're at risk!"

"Well, there aren't any computers except Matron down there, are there?" I grin crookedly, trying not to show my unease. (Best not to dwell upon the fact that before 1945 "computer" was a job description, not a machine.) "Relax, it's not contagious."

She shrugs in surrender, then gestures at the far end of the observation gallery, where a curious contraption sits above a pipe. "That's the alarm. If you want a Sister, pull the chain with the blue handle. If you want a general alarm, which will call the duty psychiatrist, pull the red handle. There are alarm handles in every room."

"Okay." Blue for a Sister, Red for a psychiatrist who is showing all the signs of being under a geas or some other form of compulsion-except that I can't check her out without attracting Matron's unwanted attention and probably tipping my hand. I begin to see why Andy didn't want to open this particular can of worms. "I can deal with that."

I head for the stairs at the far end of the gallery.

There's nothing homely about the short corridor that leads from the bottom of the staircase to the Secure Wing. Whitewashed brick walls, glass bricks near the ceiling to admit a wan echo of daylight, and doors made of metal that have no handles. Normally, going into a situation like this I'd be armed to the teeth, invocations and efferent subroutines loaded on my PDA, Hand of Glory in my pocket, and a necklace of garlic bulbs around my neck: but this time I'm naked, and nervous as a frog in his birthday suit. The first door gapes open, waiting for me. I walk past it and try not to jump out of my skin when it rattles shut behind me with a crash. There's a heavy clunk from the door ahead. As I reach it and push, it swings open to reveal a corridor floored in parquet. An old codger in a green tweed suit and bedroom slippers is shuffling out of an opening at one side, clutching an enameled metal mug full of tea. He looks at me. "Why, hello!" he croaks. "You're new here, aren't you?"

"You could say that." I try to smile. "I'm Bob. Who are you?"

"Depends who's asking, young feller. Are you a psychiatrist?"

"I don't think so."

He shuffles forward, heading toward a side bay that, as I approach it, turns out to be a day room of some sort. "Then I'm not Napoleon Bonaparte!"

Oh, very droll. The terror is fading, replaced by a sense of disappointment. I trail after him. "The staff have names for you all. Turing, Cantor, Mandelbrot, and Godel. You're not Cantor or Turing. That makes you one of Mandelbrot or Godel." The terror is fading, replaced by a sense of disappointment. I trail after him. "The staff have names for you all. Turing, Cantor, Mandelbrot, and Godel. You're not Cantor or Turing. That makes you one of Mandelbrot or Godel."

"So you're undecided?" There's a coffee table with a pile of newspapers on it in the middle of the dayroom, a couple of elderly chesterfields, and three armchairs that could have been looted from an old-age home sometime before the First World War. "And in any case, we haven't been formerly introduced. So you might as well call me Alice."

Alice-or Mandelbrot or Godel or whoever he is-sits down. The armchair nearly swallows him. He beams at my bafflement, delighted to have found a new victim for his doubtless-ancient puns.

"Well, Alice. Isn't this quite some rabbit hole you've fallen down?"

"Yes, but it's just the right size!" He seems to appreciate having somebody to talk to. "Do you know why you're here?"

"Yup." I see an expression of furtive surprise steal across his face. I nod, affably. Try to mess with my head, sonny? I'll mess with yours. Try to mess with my head, sonny? I'll mess with yours. Except that this guy is quite possibly a DSS, and if it wasn't for the constant vigilance of the Sisters and the distinct lack of electricity hereabouts, he could turn me inside out as soon as look at me. "Do you know why you're here?" Except that this guy is quite possibly a DSS, and if it wasn't for the constant vigilance of the Sisters and the distinct lack of electricity hereabouts, he could turn me inside out as soon as look at me. "Do you know why you're here?"

"Absolutely!" He nods back at me.

"So now that we've established the preliminaries, why don't we cut the bullshit?"

"Well." He takes a cautious sip of his tea, and the wrinkles on his forehead deepen. "I suppose the Board of Directors want a progress report."

If the sofa I was perched on wasn't a relative of a Venus flytrap, my first reaction would leave me clinging to the ceiling. "The who who want a-" want a-"

"Not the band, the Board." He looks mildly irritated. "It's been years since they last sent someone to spy on us."

Okay, so this is the Funny Farm; I should have been expecting delusions. Play nice, Bob. Play nice, Bob. "What are you supposed to be doing here?" I ask. "What are you supposed to be doing here?" I ask.

"Oh Lord." He rolls his eyes. "They sent a tabula rasa again?" He raises his voice. "Kurt, they sent us a tabula rasa again!"

More shuffling. A stooped figure, shock-headed with white hair, appears in the doorway. He's wearing tinted round spectacles that look like they fell off the back of a used century. "What? What?" he demands querulously.

"He doesn't know anything," Alice confides in-this must be Godel, I realize, which means Alice is Mandelbrot-Godel, then with a wink at me, "He doesn't know anything, either."

Godel shuffles into the restroom. "Is it teatime already?"

"No!" Mandelbrot puts his mug down. "Get a watch!"

"I was only asking because Alan and Georg are still playing-"

This has gone far enough. Apprehension dissolves into indignation. "It's not chess!" I point out. "And none of you are insane." Apprehension dissolves into indignation. "It's not chess!" I point out. "And none of you are insane."

"Sssh!" Godel looks alarmed. "The Sisters might overhear!" Godel looks alarmed. "The Sisters might overhear!"

"We're alone, except for Dr. Renfield upstairs, and I don't think she's paying as much attention to what's going on down here as she ought to." I stare at Godel. "In fact, she's not really one of us at all, is she? She's a shrink who specializes in K. Syndrome, and none of you are suffering from K. Syndrome. So what are you doing in here?"

"Fish-slice! Hatstand!" Godel pulls an alarming face, does a two-step backward, and lurches into the wall. Having shared a house with Pinky and Brains, I am not impressed: as displays of "look at me, woo-woo" go, Godel's is pathetic. Obviously he's never met a real schizophrenic.

"One of you wrote a letter, alleging mistreatment by the staff. It landed on my boss's desk, and he sent me to find out why."

THUD. Godel bounces off the wall again, showing remarkable resilience for such old bones. "Do shut up, old fellow," chides Mandelbrot. "You'll attract Her attention." Godel bounces off the wall again, showing remarkable resilience for such old bones. "Do shut up, old fellow," chides Mandelbrot. "You'll attract Her attention."

"I've met someone with K. Syndrome, and I shared a house with some real lunatics once," I hint. "Save it for someone who cares."

"Oh bother," says Godel, and falls silent.

"We're not mad," Mandelbrot admits. "We're just differently sane."

"Then why are you here?"

"Public health." He takes a sip of tea and pulls a face. "Everyone else's else's health. Tell me, do they still keep an IBM 1602 in the back of the steam-ironing room?" I must look blank because he sighs deeply and subsides into his chair. "Oh dear. Times change, I suppose. Look, Bob, or whoever you call yourself-we belong here. Maybe we didn't when we first checked in for the weekend seminar, but we've lived here so long that . . . You've heard of care in the community? This is our community. And we will be health. Tell me, do they still keep an IBM 1602 in the back of the steam-ironing room?" I must look blank because he sighs deeply and subsides into his chair. "Oh dear. Times change, I suppose. Look, Bob, or whoever you call yourself-we belong here. Maybe we didn't when we first checked in for the weekend seminar, but we've lived here so long that . . . You've heard of care in the community? This is our community. And we will be very very annoyed with you if you try to make us leave." annoyed with you if you try to make us leave."

Whoops. The idea of a very annoyed DSS, with or without a barbaric, pun-infested sense of humor, is enough to make anyone's blood run cold. "What makes you think I'm going to try and make you leave?" The idea of a very annoyed DSS, with or without a barbaric, pun-infested sense of humor, is enough to make anyone's blood run cold. "What makes you think I'm going to try and make you leave?"

"It's in the papers!" Godel squawks like an offended parrot. "See here!" He brandishes a tabloid at me, and I take it, disentangling it from his fingers with some difficulty. It's a local copy of the Metro Metro, somewhat sticky with marmalade, and the headline of the cover blares: NHS TRUST TO SELL ESTATE IN PFI DEAL.

"Um. I'm not sure I follow." I look to Mandelbrot in hope.

"We haven't finished yet! But they're selling off all the hospital Trust's property!" Mandelbrot bounces in his chair. "What about St. Hilda's? It was requisitioned from the St. James charitable foundation back in 1943, and for the past ten years the Ministry of Defence has been giving all those old wartime properties back to their owners to sell off to the developers. What about us?"

"Whoa!" I drop the newspaper and hold my hands up. "Nobody tells me these things!"

"Told you!" crows Godel. "He's part of the conspiracy!"