The Wheel Group sits on limitless power and hates using it. Fudged magical teleportation - biological deconstruction/reconstruction followed by transfer-of-control - is a completely real ability that they possess, but the world is real and can be traversed physically, so why tax the system? Why risk discovery? They could blip all over the world in thousand-kilometre steps, but they don't.

The Floor is real, and can be reached simply by walking if you start on the appropriate continent and know which secret paths to follow. But this is time-consuming. Case in point - the Floor's "helm" is far enough from any of its walls that crossing the patterned floor to get there is a fifteen-minute walk. Hence the subway layer.

Paolo Casaccia arrives at the miniature rail terminal in a comfortably spacious, pleasantly noiseless single-occupant pod. After he steps out, the vehicle closes its door and retreats into storage for future reference, alongside two identical siblings.

The station is low-ceilinged, and a shallow flight of steps leads through a slot in the ceiling to Floor level. Monitor duty is tedious, and a featureless plain the size of Gibraltar is no kind of home, so there are other amenities attached to this small nexus: toilets, living quarters, kitchen facilities, a water cooler. The rules are complex and ill-enforced, but manufacturing food from thin air is another thing Wheel members aren't supposed to make a habit of.

Casaccia is a dark-haired, immaculately suited thirty-year-old, and has been for some thirty years. He jogs up the steps into bright sunshine. It is a glorious day on the Floor. The focal point for the monumental skybox screen is set to somewhere off the Malaysian coast, and the displays reproduce the sunlight accurately enough to tan. It is also a quiet day, with only Adam King at the world's controls and not a lot of business. No fires, no firefighting. It's a day when King might be amenable to interruption.

King puts his book down. Casaccia steps across the invisible boundary of the D-class magic circle, thereby officially joining the operational team.

"This isn't an emergency," he explains.

"Clearly. High energy edge cases?" King suggests hopefully, but he knows Casaccia's areas of expertise and this isn't a serious hope. This is going to be about security.

Casaccia waves a hand. The Malaysian horizon blots itself out, replaced with skyscraper-tall twenty-four-hour news feeds, and multi-spectrum aerial scans of a particular house in a particular English city. The fixed headline, bold white on red, is: "MAGIC BOMBING".

It's a world first, but not entirely an unanticipated one. In fact, it's an emerging phenomenon which the Wheel Group has been awaiting patiently for some years. It marks an impressive milestone in the advancement of magical technology. Not that champagne would be appropriate, exactly.

King sighs deeply and cracks a knuckle. "Technology makes everything easier," he observes phlegmatically. "It turns out that 'everything' includes bad things. Film at eleven."

"Film indeed," Casaccia says. "The bombing itself was almost twelve hours ago. The leaked facts about the bomb's construction are much more recent. That was when I caught it, on the news. You're about to say that we should have been alerted within milliseconds of the detonation. And you'd be right. Watch this."

He gestures at the half of the display which is showing Wheel-internal data, and singles out a particular false-colour overhead picture. There are green pinpricks of police milling about the blast crater from the ruined home. This is one of the chi feeds, piped in directly from the listening post. The feed is almost totally dark, because no magic is being spent. The crime scene is just a furred black and blue shadow.

Casaccia throws up a timestamp and rolls the scene back by half a day, to the point where the green points scatter. "We only have a little data about what the house's interior looked like," he explains. "And it's been destroyed now, so this is the best floor plan going. Here's how it happens. This man, inside the house, is there from the start. These two other people arrive separately and go in - I think they're looking for him, or someone else. I don't know who any of them are, yet. The first man goes into this room here, hiding. The other two hang around in the main room, then go into this second room. The first man comes out, goes to the living room, pauses for a second, then makes for the door. The other two come back. Something confusing happens with all three of them, and then this is the detonation point. After which, all three dots are gone."

"What does it look like with the full chi readout?" King asks. It's the first magic bomb ever detonated. The data will be fantastically significant. This is particularly true if the Wheel's magic-powering gigaspells are going to have to support a great deal of thaumic warfare in the foreseeable future.

Casaccia does not answer the question. He steps away from the screen and folds his arms, as if waiting for King to do something.

King looks at him, puzzled. Then he waves a hand, dismissing Casaccia's feed and summoning a query of his own. After a moment, he frowns. He brings Casaccia's feed back so that he can compare them, side by side.

They are identical. They are, in fact, the same feed. The chi feed simply shows no chi. No magical usage.

"It was magic," Casaccia says. "I've got heavyweight observation on that site now, full-spectrum, thaumic and everything else. There's a whole bunch of secondary evidence, including fragments of the lotus-leaf assembly. It was a good magic bomb. A great first attempt. It's just that the explosion didn't register on the listening post. Because the bomber... the first man, this man... is masked out. He uses magic, and he seems to be still constrained within its laws. But there's no chi emission. He used magic. But the akashic records are blank."

Casaccia turns to King. "I can see from your expression that you understand how big a problem this is."

King closes his eyes, and gears up. "Alright. How'd he do it?"

"I don't know how," Casaccia says. "I'm assuming he used a spell of some kind, but I can find no record of that man ever using magic. Not from the day he was born to the day he died."

"No," King says. "No. I remember this. We did a study. We tried to build an akashic scrambler ourselves, to see if it was possible. We couldn't do it."

"We could do it," Casaccia asserts. "We did do it. But none of us could do it without releasing chi in the initial cast. It's that initial cast which we look out for. After the study, Kila Arkov built a parameter-trap for it." A gesture summons a visual representation of the same. "We ran it against all of history and found nothing. It's been running continuously since that day, and has found nothing."

"So this man had technology that was a few generations ahead of the curve," King says.

"No," says Casaccia. "This man did something that we can't do at all, and we built magic. That's not a few generations. That's... twenty, I don't know. It was supposed to be impossible. We watch over everybody's shoulder. That's what the records are supposed to do. That's what they're for. Our surveillance system isn't failing. It is a failure.

"We have no way of discovering how long this man was off the grid. Or what else he did while he was off the grid. Or who else is still off the grid right now, or what they're doing."

"Do you have any good news?" King asks dryly.

"I can set some lower bounds on how fucked we are." Casaccia brings up a new map and launches into part two. "Hours after the bombing, the police raided this location, a private magic research institute in western England. Plotting the historical movements of our bomber, we see he's been there, ooh, a thousand times. Whatever his name was, he worked there."

"But he's never used magic," King says. "I mean-- he's never been recorded using magic."

"Nobody at the Chedbury Bridge Institute has ever been recorded using magic," Casaccia says. "Here's the relevant feed. You can go back twenty years, to before it existed. It's a blind spot."

King does exactly this.

"...Could be that they're theoreticians," he says, but it's clear he doesn't believe it.

"Or maybe," Casaccia says, "every single magic-capable individual at the site is cloaked. There are sixty full-time employees. I'd estimate forty to fifty would be magical engineers."

"We've got no idea what those fifty people are doing?"

"It's worse than 'no idea', Adam. We know for a fact that what they're doing is conducting violence. One of their people blew a home up. You know what I'm saying? This is a base. And this is just the one that we know of. One thing which I can say for certain is that that wasn't the first magic bomb ever detonated. It couldn't be. Nobody can enact an explosion that clean without dozens of failed attempts and months of practice. Or weeks of training.

"The only way we could get wind of something like this is if we saw someone cast a spell with our own eyes, but the spell didn't show up in the records. We got extremely lucky, or they got extremely careless. Either way, there's no chance that this is the opening shot.

"Do you want the final piece of this nightmare?"

"I think I've worked it out already," says King, who is staring at the news feeds on the horizon. There is new information there.

"After the raid, the police found two freshly-murdered bodies on the Institute site. A man and a woman. The home that blew up? It belonged to them. The man was named Nicholas Laughon. He may be significant. I don't know yet. I'm working on it. The woman is his girlfriend. Laura Ferno."

"I know that name," King says.

"Yes. You do. She's the daughter of Rachel Ferno."

"Rachel..."

"Whom we knew by a different name."

King inhales sharply, as if stung. "...What does that mean? Laura Ferno isn't one of ours. Rachel's dead. The privileges aren't inherited. What would they want with her? Is it an attack on us? Is it a message?"

"Of course it's a message," says Casaccia. "The message is that we need more information."

King says, "We need someone on the ground in the UK as soon as possible. And by 'someone', I mean Exa, obviously."

"I got him moving as soon as the news broke," Casaccia says. "He'll be on the site in seven-and-a-half hours." King frowns at this, but Casaccia repeats: "It's not an emergency. Yet. You'll be the first to know when my position on that changes. Let's say we're a decade behind. Let's not jeopardise our investigation by jumping all the way from peacetime to DEFCON 2. Let's take the extra seven-and-a-half hours to assemble some data."

"Okay. Where does Exa go first?" King asks. "Chedbury Bridge?"

Casaccia cackles unhappily. "Oh, you don't want to know the size of the law enforcement machine which is on this. Everybody who was on the Institute site at the time of the raid has been arrested, and everybody who wasn't has been rounded up for questioning. We can listen in on the questions, within reason, but we know nobody's going to ask the questions we really care about. Getting Exa physically into the investigation so he can start taking meaningful data might be dicey without breaking the rules. I advise caution, if only because of how magically-charged the situation already is.

"No, our best option is the key witness to the bombing. Rachel's other daughter, Laura's twin sister. Natalie Ferno."

King paces a little. He clearly isn't happy with moving this slowly. "Why are you so calm? Why don't you want all hands on deck? I do."

"Too many cooks," Casaccia says. "I'm calling the people who do matter. They'll be here. As for the rest: off the record, we've gone soft, Adam. The number of us who'd even respond to an all-hands call is shrinking, and half of those who would show up would be good for nothing when they did."

"And you're sure this isn't a deliberate attack?"

Casaccia shakes his head. "Everything is an attack. Everything is deliberate. Everybody is against us. I am Paolo Casaccia: I am security. This is the mode I work in. I will notify you as soon as it becomes appropriate for you to do the same.

"Look: we're starting from a position of weakness. That's unusual and scary. But our systems are still inviolate, I've checked. And we hold every other card."

*

At the mention of her sister, Laura knows it's time to start moving again, and at "every other card", she's softly descending the steps to the subway layer, fighting the urge to laugh out loud. Although she cannot be seen with baseline eyes, she can certainly be heard.

When this began, she had an optimistic lead time of months. Lurking behind Adam King's shoulder, she's seen that head start contract to at most a day. It would be entirely possible to stick around and watch the Wheel organisation track her down in real time, and it might even be fun to watch their expressions when they turn around and dispel her cloak of invisibility and - most likely - straight-up kill her. But she has places to be.

The fact that she's dead is news to Laura. No ripcord, she thinks. Kazuya said this is what would happen in the event of a raid. There's only one of me, now. One of me and zero of Nick.

There are three pods stored at the rail terminal. Laura's unfolds with a clean metallic whisper, perfectly machined. Even Laura can barely hear it. She climbs in, instructs it to continue to descend, and leaves the Floor.

*

Inventory:

A suit of armour. A memorised route of descent. And a one-gram speck of gold retrieved from her boyfriend's corpse's suit pocket.

Laura barely needs equipment anymore. Working with the golden artifact is like flying. For her whole magical life she was trapped under the weight of everything that needed to be held in her head. Invisibility is a hugely difficult single spell, but it breaks down trivially into a slideshow of tiny ideas. All you need to do is cast each one correctly. Then you can forget about it and work on the next.

You can forget about it! And it keeps working, just the way you first imagined it! You handle the complexity once, and magic itself handles the complexity forever. It's a maddening whisper of what māyā is really like.

The tiny railpod changes direction like a gnat, automatically swinging the bucket seat around to protect Laura from being thrown out at the curves. The acceleration is punishing, but her armour and the seatbelts soften the effects. In the darkness it's close to impossible to tell the general heading, but with that sixth magical sense Laura can feel the colossal, dull shapes of the listening machines moving past. Tracks branch and merge.

Within a few seconds Laura's pod has been piped all the way to the listening post's backbone. The seat flicks her completely upside-down for a moment, so that the pod can perform a steep negative-gee turn. Then she's accelerating directly into the Earth's core so hard that she's pinned against the pod's ceiling, facing straight down the fifteen-kilometre-long vertical shaft.

At the very bottom of the pit, Laura persuades herself that she can see a red-hot pinpoint.

You're going to die, says that creeping black doubt in Laura's mind. They've met before, under far more intense circumstances. But this is a longer and deeper death. Those men are murderers. You were watching them as they set out to kill you. It's just a matter of how fast they catch on. This hunt could end seconds from now. The more competently you behave, the greater the threat you represent to them, and the faster they'll end you. And if they're slow, you'll go mad waiting. And if they never catch you, you'll surely get lost and die yourself.

"I know you," Laura tells it.

The other Watson was new. Inexperienced. You got as lucky as lucky ever gets. Next time, you won't even hear his tread.

"Lifelines branch," Laura says. "I'm not scared of you anymore. I have insurance."

You really believe that?

*

There's flickover and then there's a longer period of braking. The pod levels off, travelling through the final few layers of superstructure at a relatively sedate rate. Laura can almost see the walls passing.

The pod brakes to a seamless halt at the deepest terminal in the listening post's internal network, thirty-one thousand, five hundred metres below ground level. At this depth, the listening post is starting to fray into individual tendrils, protruding from the Indo-Australian Plate's lower reaches through the Mohorovičić discontinuity and into planet Earth's upper mantle. This is the geothermal zone. The number of "real" people who've visited this depth in person is zero. Laura wonders if she gets to coin the term. "Mohonaut"?

The arrival hall is approximately ovoidal, a vast iron stomach lined with thick girderwork. A walkway crosses the floor to the far end. There is still no light, except for the weak blue illumination from the pod's interior. The texture of the darkness here is the same as in the rest of the listening post's semi-habitable spaces. So is the hostility of the atmosphere. Laura persuades herself that she can feel the teratonnes of extra pressure. Surely, no conventional human material can hold a habitable space open at this depth. It can't just be thick iron and thick girders. This has to be an active structure, geothermally powered, magically supported.

During her journey, Laura has been exploring her suit's characteristics. She built it in a second, on a whim, in a dream-- "I want one of what Kaz is wearing". And here it is, a miraculous reality. It is light enough to forget about, comfortable enough to sleep in, and almost robust enough to do so while standing up. The gauntlets transmit tactile sensations to her fingers. The boots massage her feet to maintain circulation. The helmet can turn completely transparent - it does this by retracting all of its thermal management foam and extra gadgetry into a compressed ring around her neck. Why? Because of a silly thing Kazuya needed once, in a dream. As far as Laura can tell, the suit is an entirely physical object, making no use of magic whatsoever. Wearing it confers a sensation of incredible safety. The only possible criticism is its tedious, almost lazy appearance-- large, flat, uniformly matte grey plates.

But she's thirty klicks below ground, now. And no spooky suit can possibly protect her from an implosion at this depth.

The railpod folds itself behind a thick, seamless steel bulkhead. The arrival hall plunges into darkness, which Laura dispels, this time using the suit's brilliant floods. If she had to guess, she'd say the batteries were plated across her back somehow, but she honestly doesn't know.

The walk across the arrival hall is only a few minutes. The hall's strange bumpy girders cast moving shadows which keep catching Laura's attention. When she looks, there's never anything there. She reminds herself that the place is sterile.

At the far end of the hall is an installation where, apparently, some kind of particle accelerator is partially exposed. A thick pipe, five or six metres in diameter, enters the hall from one side, curves gently through it at a slight rising angle, and leaves from the other. The visible curvature sets limits on the full ring's diameter. It is less than two kilometres wide.

Laura has never seen magical runic patterns drawn on such a large scale. Within the individual flowing channels, she can see nested patterns, carved into the base and even the wall of the first level of carvings. The complexity is bewildering at first, but a trained eye can quickly pick out the frequent repeated patterns.

This is a magic ring. More technically, it's sixty-two magic rings, interlocked and cooperating, all bound with conventional hoops of blue-painted tungsten. From the left and the right, Laura hears the dull roar of hardcore climate control engineering, driven by more magic. Precise shaping is critically important to magical efficiency, and temperature variations would cause structural shifts.

The pioneers at Montauk would recognise its purpose with just a glance, but figuring the thing's maximum capacity would leave them standing. This is the bilge battery at the base of the world.

All living humans generate waste mana, active mages and baselines alike. The quantity is insignificant to a magical machine of this size. Humanity has a few orders of magnitude to climb before it reaches Kardashev I.

But: from five known sites on Earth (a figure set to increase to seven or eight once surveys are completed), geothermal mana is naturally occurring. The mana is generated, coils into the sky, cools for a day, and evaporates into waste, at which point it is not only useless for all human purposes but invisible and undetectable. It sinks into the Earth, becoming presumably unrecoverable.

And then it is drawn here.

A time may well be coming when humans can steal one another's mana. Soon after that, a time may come when humans can do the same to the vast meta-mage that is planet Earth. This would instantly turn every geothermal mana source from a worthless (if spectacular) natural phenomenon into a billion-dollar oilfield.

Or then again, that time may never come. It very much depends on what is in the Wheel Group's long-term development chart for magical industry. It depends who figures what out, and when, and how much of a nudge they need to find the important threads.

Laura's waste mana reclamation process makes the entire question academic. It worked up at Hatt Group, and it'll work here. All it took to build was a month of hard labour and a painfully slippery True Name aliasing trick. "Trick" is the term she would use, not "spell". Even on close inspection, it's hard to know how it works. It's almost sleight-of-hand.

She raises one fist - she barely needs to think about what she's doing - and three long streams of lightning stab out from it: two flanking her forearm, and the third directly upwards from between her second and third finger.

She has completed less than one two-hundredth of her descent, but the hardest part is over.

*

Kazuya "Ra" Tanako said he crossed T-world by dreaming of scramjets. The man thought too small. Everybody thinks too small.

Laura stands directly on top of the listening post's virtual representation, the Manhattan-sized arthropod carapace. There is a kind of landing pad here. It's exactly as wide as Laura needs it to be. The glass universe is almost as dark as it ever is. At one end of the sky is the familiar triple-pointed galaxy, a little lower in the sky than is typical. At the other... what is that? Could those be city lights reflected off low cloud? No...

In T-world, you can have anything you can ask for. You're not even limited by your imagination. Laura knows what she wants, down to the level of bolts and circuits. A Space Shuttle launch stack takes shape above her. Tank, boosters, orbiter. Three gigantic engine bells, aimed straight down.

Laura flitters around the stack, conducting a practiced inspection. Instead of climbing inside, she hitches herself to the orbiter's exterior. She races through the launch checklist as fast as she can recall the steps, like a flipbook. The stack lights up.

Time doesn't mean anything to T-world, but it does to Laura Ferno. After a rigorously computed roll manoeuvre and six minutes of flight time, the unnamed Shuttle has stopped ascending and is accelerating horizontally, at an altitude that is T-world's equivalent of the threshold of space. Laura lets the SRBs empty themselves and disconnect, and simply builds new ones. Telemetry flickers in front of her. The velocity reading recalibrates itself, from kilometres per hour to Mach number to kilometres per second.

Looking over the edge of the orbiter and down, Laura can still just about discern individual features of glass geography. A mountain range rushes past, rising and falling, jagged like a graphic equaliser. On the final, tallest peak of the range she sees something. Someone.

It's a human figure made of cobweb-thin crystal, with his hand in the air, waving. Laura almost misses him. She turns and waves back. Her hair doesn't whip in the wind-- she is protected by the suit and extra layers of imagined shielding. The wind chill at this altitude and velocity would be enough to kill instantly.

In an eyeblink, the figure and the entirety of the mountain range are gone into the distance.

Laura cackles, turns to face forward again and steadies herself.

Take the centre of the galaxy as your North Star, and head directly south for... call it another light year. Call it a light decade. Whatever it takes, just don't stop.

In accordance with procedure, dense waves of flying demons descend on the rocketship, but Laura barely perceives them. At this relative speed, each wave is as thin as tissue, and the force of collision turns the unlucky horrors into black mist. Physical barriers rise too, but Laura has so much thaumic and kinetic energy wound up behind her that they shatter as if shot. Brute force and ignorance. There's no stopping this thing.

And after that...

It takes almost as long as a real sunrise. A yellow star rises, directly ahead of her. It is the size of the Sun, but three-pointed, forming a Y. Under the new light, the glass landscape turns sapphire, reflecting long rainbow patterns like the back of an optical disc.

Directly beneath the star-shaped star, at Tanako's world's precise South Pole, is a second artificial structure. There is no direct physical route between this object and the surface of the Earth. The only way to signal this deep is using chi, or by somehow applying modulation to a major tectonic plate movement. And the only way to get here in person is to cheat the universe.

Laura's getting good at that.

The listening post is a toy, a cheap plastic spy microphone glued to the underside of the world. This is genuine God-hardware, an artificial country at the centre of the world. It exists under pressure measured in millions of atmospheres, and temperatures beyond the boiling point of tungsten. This is the machine which makes magic.

Laura produces more SRBs, and trains her space rocket directly on the object's core.