"I'm trying to find Laura Ferno. You're her emergency contact," is what the fellow on the phone leads with, Hollywood-style, no greeting.

"Is it an emergency?" Natalie Ferno asks, mildly refreshed to be getting to the point of the conversation so quickly. She keeps a thick pad of A4 next to the phone. It is measurably thicker with the weight of doodles. People, in Nat's experience, can lock themselves into a kind of verbal holding pattern, constantly emitting syllables while never advancing the conversation.

"It's two halves of an emergency," says the man.

"Who is this?"

"Anil Devi, I worked with your sister at Hatt Group."

"You fired her," Nat observes.

Anil Devi, personally, worked with Laura Ferno only for a few weeks altogether while she was still in gainful employment. The decision to fire her was made completely in his absence, for reasons completely unrelated to him. "No," he explains. On the other hand, Devi is contacting Natalie Ferno as a formal representative of Hatt Group with a view to reinstating Laura in some - any - professional capacity as soon as possible, which means he is Hatt Group's front end from Nat's perspective. So, "Yes," he adds. "It doesn't matter. We need her to come back."

"Why?"

"That's confidential."

"Is it," Nat asks again, "an emergency?"

"...I need to find her very urgently."

So, no. Nat hangs up.

*

Then she thinks again.

She hasn't heard from Laura in weeks. But Laura's like that. She is a low-maintenance relative.

Nat also hasn't heard from Nick in that amount of time. That's much less usual.

If Hatt Group have been reduced to pursuing emergency contacts, then Laura's not responding to their phone calls or emails.

Laura loved that job. She saw a serious chance of becoming an astronaut in that job. Losing the chance devastated her. Laura would never pass up another chance at that chance. She would never ignore them if they reached out.

Nat calls Laura's mobile. The call goes straight to voicemail, as if the phone itself has ceased to exist.

She calls Laura and Nick's land line. Answering machine.

She calls Nick's mobile. Voicemail.

Neither are on IM. She emails them both, then drums her fingers for a while, not really expecting any response.

She calls Nick's school. Nick is AWOL, and has lost his job.

She calls Nick's friends, although she doesn't know many of their numbers. The story is consistent: Nick and Laura are travelling around the world. They're probably in Japan right now.

No contact information. No forwarding numbers. Not even a postcard.

It's an interesting combination of stories. Laura's the kind of person who could go off-grid for a month before anybody noticed. Nick Laughon isn't, but he's the primordial avatar of itchy feet, so if he needed to disappear, he could buy about the same amount of time with a quick one-liner like "I'm going around the world"...

Two half-emergencies. One: Hatt Group desperately, desperately need Laura Ferno back. Two: Laura and her boyfriend are missing. Missing, presumed...

At this point the possibilities become a forest.

No presumption. Nat needs more data.

*

She arrives at Laura's house not long before dusk. It's the greyish, coldish part of the British day where you squint a little and go to remove sunglasses that you aren't wearing.

There is a man at Laura's door. Facing the door, as if having just knocked. Natalie strides up behind him. "You must be Anil Devi," she announces, surprising him.

He turns. Spiky black hair, the kind of face which seems to be perpetually grinning regardless of mood. "Laura!"

"No."

Devi blinks. "Natalie. Natalie Ferno. Laura didn't say you were identical twins."

"We aren't identical."

"That's why."

"Go home," Natalie tells him. "If I find her, I'll tell her to call you." She moves around Devi, producing a spare key, and goes to unlock the door.

"Did she tell you why she was fired?" Devi asks.

"Maybe."

"Did she tell you she was trying to resurrect your mother?"

Natalie stops on the threshold.

She says, carefully, "I was wondering how much you people knew. Yes, word got around. But it didn't work, obviously. Otherwise you'd never have fired her."

"It worked," Devi says.

Natalie's eyes widen.

"Sort of," Devi adds, hurriedly.

*

Inside, Devi tells the story.

"The lab says it's dead meat," he says. "Real meat, dead but formerly living. Real DNA from a completely unknown taxon. Maybe some proto-hominid which evolved in a radioactive wasteland for a few hundred thousand years. And that, in itself, is a bloody significant mystery."

"Maybe it was intelligently designed," Natalie suggests.

Devi shrugs. "Number of biologists in this conversation, zero. But the real point is: she brought it back. Real mass, comparable with a human. From a place which strictly doesn't exist. We've got no idea how she did it using essentially no mana, but we sure as hell need to know. Hint: mass-energy conservation is over."

"Death is over," Natalie says.

"Yeah," Devi says. "Death is potentially over. You see why I pushed this into emergency territory."

"I see why you got permission to violate some NDAs," Natalie says.

"We heard you were a professional mage too," Devi says. "It turns out we approached you in university at the same time as Laura. All things considered, Ed Hatt thought it was worth cutting you in."

"Alright," Natalie says. "We're on the same page."

"Where is Laura?" Devi asks.

Natalie shares what she's worked out so far. "All Laura's magical equipment is missing. No sign of a break-in, which means Laura took it all with her. Laura's daily carry is enough that she clatters when she moves, but her whole collection weighs a lot and is worth a lot more. She owns one-of-a-kind pieces which she built with her own hands. She'd never fly with it. Forget cameras and lenses, that is the kind of valuable property which mysteriously vanishes from hold luggage. Contradiction."

"So let's say they're still in this country," Devi surmises. "When was the last time you spoke to her?"

"Just after she was fired." Natalie recalls a despairing and unhappy Laura Ferno in search of a source of limitless magical energy, named Ra. "I called her an idiot. ...You know what the real puzzle here is? Nick's missing as well."

"Nick...?"

"Laughon. Her boyfriend. Laura's a bad scientist. You were right to fire her. Recklessness, unsafe experimentation. The drawing of rash conclusions heavily influenced by personal feelings. For Laura to disappear for weeks on a quest to do something bizarre and misguided isn't remotely out of character.

"But Nick's missing too. He's the grounded half of the relationship. He should have talked her down. He'd be the one to bring her--"

Oh.

"--back... to... reality."

Oh no.

"She's summoned a demon into the body of her boyfriend," Natalie announces.

Devi does not have a coherent immediate response to this. Demons are not a standard component of the magical engineering canon.

"What kind of demon?" he eventually manages.

"A demon! A malevolent spirit. 'Ra'."

"I'm sorry. What kind of mage are you?"

"Theoretical thaumic physicist."

Devi changes gear.

Terminology has become somewhat confused in recent decades. Technically speaking, magical engineers are supposed to refer to themselves exclusively as "mages", because of the abbreviation, MagE. "Wizard", "witch", "warlock" and "sorcerer" are generally associated with fictional characters or crazy people; "magician" and "conjuror" are reserved for stage performers. All of this is perfectly clear from the perspective of those working in the magical community. Unfortunately, on the outside, it's fuzzier. There's no trademark or law to prevent non-mages from calling themselves mages. It's not even a title which requires a certain qualification, like "doctor".

There are "psychics" who call themselves mages. These people cheerfully lift choice terms from magical engineering, craft them into something that's obviously nonsense to anybody with a day's experience with the real topic, and dupe saps for cash. The popular quantum mechanics books have become almost impressive in their creative meaninglessness.

One could very easily get to the end of such a book and consider oneself a "theoretical thaumic physicist".

"Why do you think Laura would summon a demon?" Devi asks.

Natalie's reasoning is apparently effortless. "She's going to try her experiment again. To do that, she needs a ridiculous amount of mana, more than she can generate in years by herself. Ra has that power."

Devi chooses each word carefully, as if stepping forward across ice. "Is... is 'Ra' dangerous?"

Ra was last seen trying to liberate enough geological mana to blow up Iceland.

"Yes," says Natalie.

"Does Laura know this?"

"Oh, my, yes," Natalie says.

"Is Laura really stupid enough to trust this... being?"

"Entirely the wrong question," Natalie says. "You should be asking if she's stupid enough to think she can control it. And she is. She is actually, in her own way, a pretty formidable human being. Up to a point."

Devi doesn't want to ask the last question. He does anyway.

"What does Ra want?"

Natalie's expression darkens, but she doesn't answer.

*

The computer room.

Natalie knows Laura's password. She shoulder-surfed it a year or two ago, never mentioned it, and Laura's never changed it. Natalie would feel guilt, if there was time.

She pulls up the browser cache. Last activity, weeks ago. Printed directions to a particular postcode in the West Country, an isolated compound in a forest in the back of beyond. A private magical research laboratory called the Chedbury Bridge Institute.

"What kind of magic do you do?" Devi asks casually, hovering behind her. Natalie assumes that he has shoulder-surfed Laura's password in turn. She makes a mental note to change it once he isn't looking.

"Mmm? I know eset ," Natalie says.

"Anything else?"

"No."

"You only know one spell?"

"Yup."

"You don't know uum ?"

"Why would I learn a spell which does nothing?"

Devi solidifies his conclusion about Natalie Ferno: layperson. Laura, he thinks, is the brains of the family. Natalie is a neo-pagan imitator of her sister, a chanter of nonsense-spells at summer solstice near particular rocks. Natalie is interpreting the evil of pedestrian humans in the most meaningful terms she's familiar with. Natalie is a 'witch' - which is to say, a crazy person.

Devi asks, "What's the postcode?"

Natalie reads it out.

"Noted," says Devi. He goes to leave. "I'm calling the police."

"Wait!"

"'Wait'?" asks Devi, loading as much scepticism and frank disgust into this word as possible.

"What will you tell them?"

"'Laura Ferno's been abducted by her boyfriend, Nick Laughon.'"

"Nick Laughon hasn't done anything! There's no sign of forced abduction. Laura's being manipulated!"

"Do I care? Do the police care? Two people are missing, and we have reason to believe one's in danger from the other. So magic is involved. Is magic a separate legal jurisdiction?"

"I think we can straighten this out without getting the police involved--" Natalie begins.

"Let's get Nick Laughon's body in a jail cell," Devi says, "and, if you really think it's going to make a difference, you can attempt an 'exorcism'. Grind some herbs, draw runes in chalk and mouse blood or whatever it is you do."

"What?"

"I don't buy 'demon'," Devi says. "I'm veering strongly towards 'scumbag'. And I don't think you know what thaumic physics even is."

Nobody can find the biological component of magic. Nobody knows which cells in the human body register magical activity, or why it takes a year-plus of training before they work. It's mythical and inconsistent and inexplicable. Maybe it's a system of signals which is always there, but the human brain needs to be tuned before they can be unscrambled into something detectable. Like language acquisition.

It doesn't matter.

Natalie Ferno and Anil Devi both sense the reaction starting in the living room. Their heads turn almost simultaneously to look at the same unseen point on the other side of the wall.

Devi dashes back through.

The weapon resembles a silver, mechanical lotus flower. It is a sophisticated, nest-like fan of magic rings and nodules, engineered like a pop-up book, probably small enough when flat to fit into a breast pocket. The density of mana flux at its focal point is so bright in the thaumic spectrum that standing in its presence is physically painful. There's heat radiating off it too, and curls of invisible chemical vapour, the precursor to a thaumically-accelerated bomb.

Nobody has built a magic-based bomb before, and not for lack of trying. Devi and Natalie know this. They're looking at something delicate and brand new and unique, like a Fabergé egg. It is a compact packet of hugely inventive destructive power. It sits on a mundane coffee table in the cramped living room of a beige house, almost too beautiful to be allowed to detonate.

For a split second, neither of them can look away from it.

"How did that get in here?" Nat says.

"Run!" Devi screams, physically pushing Nat towards the door.

"Wait," Nat says.

Devi is, again, aghast at Natalie's suggestion. "What are you doing?"

"Wait!" Nat twists past him, lunges for a cupboard and pulls out the one piece of equipment which Laura didn't take with her: a one-point-eight-metre oaken bo.

Nat didn't hear a door move. Nat has sixty percent of the theory of invisibility laid down. The rest is just boring practical problems, like fitting the spell into fewer than ten human minds and a piece of machinery which weighs less than a tonne. The short title is "Fast-adapting Bezier-controlled duplex oracles". The only major question marks are around wavelength assignment--

She hasn't heard the door move, which means the invisible man must still be here. He must have been here the entire time they were in the house. Hovering, silently. Listening in.

Surely he left time for a getaway. Surely that's enough time to find him and wring the abort code out of him.

Nat closes her eyes for one second. In any other situation, she'd be searching, with extreme difficulty, for a volume of empty air which was detectably consuming magic. Like a poltergeist. But the house is saturated with thaumic radiation. So instead she hunts for the shadow.

It's in the hall. Nat keeps her eyes screwed up, it's the only way to find the thing reliably. Lacking room to swing, she propels the bo end-first, directly into the shadow's midsection.

Transmuting light into invisible chi particles and back is one thing. Blocking a heavy impact from a physical object is an entirely different engineering problem. The trespasser's cloak shuts off with a snap like a mousetrap. The man behind the cloak crumples up, gasping. He is a nobody, his entire image is cultivated to project "nondescript". A shirt, some shoes, hair, an age.

Natalie hits him again with the bo, bloodying his nose-- a technique which bojutsu strictly outlaws, as Natalie would know if she'd ever studied it. She catches his wrist and hurls him back into the living room, directly at the bomb. The man scrambles to avoid falling into it, and ends up crashing into the coffee table and injuring his knee quite badly.

"Jesus Christ!" is Anil Devi's reaction.

"Turn the bomb off or die," Natalie tells the trespasser. She is almost having to shout over the machine now. She holds the bo in front of her, defensively, and circles around to cover Devi. "You know you have time!" Without turning around, she adds, "Devi, don't move!"

Devi doesn't move.

"Like I care," says the man, sneering. "Like I'm singular! Elth ra mukhth entana daneda. "

It's the last exotic ingredient. The syllables spill from the man's lips like virulent red muck dripping from a test tube into the cauldron. And like witches and wizards, psychics and media, all three mages feel a figurative foreshock of the imminent future.

Natalie grabs Devi's hand. " Anh zero EPTRO zui-- "

*

There is a small discontinuity.

Over the street from Laura Ferno's address is - not unexpectedly - another row of houses. The house directly opposite has an immaculate garden in front of it. Millimetre-long grass, raked pebbles, perfect red and blue poinsettias. It takes Devi a moment to realise that this is where he has landed.

He is upright, splayed against the back of the garden and the wall beneath the house's shattered front bay window, with one arm hooked over into the house itself. The wall he's lying against is broken, as if hit by a roughly Devi-shaped truck. Devi is strewn with tiny pieces of broken double glazing, and it takes him another moment to realise that they are still being held a few centimetres away from his skin by Natalie Ferno's force field.

He recognises the bird bath. He is looking at it from the opposite angle.

"Ferno?" he shouts, and hears nothing. His organs and bones judder. The field obviously absorbed a huge percentage of the shock.

Over the road at the epicentre, there isn't a house anymore, just a blackened pit. The blast has been impressively precise, barely scorching the houses on either side. Pieces are still falling from the sky; a hard rain of roof tiles and frame. It's unreal.

".........." says a voice.

"What?" Devi shouts, looking around. He feels like a three-dimensional bruise.

Natalie has landed inside, on the other side of the same wall. In fact, she has landed on a sofa, and they are therefore seated back to back. They are still joined, through the broken window. She is holding on to his wrist, latched to it like a hawk's talon.

"I said I changed my mind," Nat says, louder. "You should call the police."

As Natalie releases her grip, the shield closes down, and both of them are now covered in fresh glass and rubble and dust, like a parsley garnish.

They never place the call, but miraculously the police appear all by themselves.

*

The sun has gone down. There are dozens of vehicles and seemingly hundreds of police. The street is filled with flashing lights and high visibility vests.

Natalie has learned her lesson. Speaking to the shadow-chinned, unflappable layperson officer who takes her statement, she avoids raising hypotheses of consciousness displacement, or of megalomaniacal minds invading from other planes of magical existence. She structures her words factually.

"My sister is missing since four weeks ago, and her boyfriend is too. Either he's abducted her, or both of them are in the hands of some third party. A man named Ra just blew up their house to stop me from tracking them, but he failed, and I know where they are. I think Laura's involved in something really dangerous, and we need to find her right now, and by 'we' I mean you and me and that guy there." She points at Anil Devi, who is in the middle of giving his own statement, and who looks up for a second, confused.

"Why you?" the officer asks, calmly, scribbling notes. Anachronism? But the scene is far too noisy to record audio.

Nat says, "Because Laura always carries a particular collection of magical equipment with her. With a high-powered eset spell and a bit of trigonometry I can find her behind a kilometre of steel. In any case, this is a magic problem. Laura's a mage, I'm a mage, Anil's a mage, the bomber was a mage. Do you have mages on the force?"

"No," says the officer.

"Magic is real," Natalie says. "Magic crime has been real since 1998. Magic terrorism has just this hour become real. You need expert outside consultation.

"And I think--" And Natalie stops for a second, because this last thought hasn't come from the right place in her mind. Natalie Ferno is a thinker who starts from a collection of facts and turns the handle until they extrude a conclusion. But this idea is from her imagination, inflammatory, fabricated to get the police's attention. And yet, it may almost add up.

"I think," she says, "my sister might have been radicalised."

*

Time is a factor.

They won't let them go.

Natalie Ferno and Anil Devi are kept around for hours, hours, having information dragged out of them. Descriptions of the late, lamented bomber, whose description is entirely irrelevant. Descriptions of the structure of the magic bomb, a breed of device that every military organisation in the world has been trying to build. (Both Natalie and Devi, despite being questioned separately, instinctively play it cagey. In truth, given a few days to compare notes, they could produce blueprints and operating instructions in multiple languages.) How do you think the bomb worked? Well, largely, by magic. How do you think he got into the house? A spare key, possibly stolen from a fake rock in the garden, or maybe even given to him by Laura herself. How did you know there was someone in the house? Magic. How did you survive the explosion? Magic, idiots!

Injuries to people in nearby houses, damaged hearing, property damage, vehicular damage, falling rubble, forensic analysis, fingerprints, insurance, thousands of flash photographs.

This is a race against time, Natalie Ferno tells them outright, over and over again. The bomb was planted just at the instant that she and Devi discovered the next link in the trail. If that information wasn't critically time-sensitive, the house would not have blown up. Laura's involved in this thing right now.

"We're taking this very seriously. We're doing everything we can to find your sister as soon as possible."

It takes Natalie several hours to realise that this isn't incompetence, some bloated civil machine that takes time to get up to speed. The police have been playing the information hygiene game for much longer than she has. Information goes into an investigation, and it doesn't come out. And she's on the wrong side of the wall.

*

"Alright, here's the thing," says the sergeant who first interviewed Natalie. "Your offer of expertise in the magical field has been percolating upwards, and it seems to have found someone in charge who's keen to get a magical opinion or two."

"Here?" Devi asks.

"This is a bomb site," says the sergeant, whose last name is Henders and whose first name might as well be Sergeant. "We can do bomb sites, and it'll still be here in the morning. Over at Chedbury, though, is a big pile of magical machinery which nobody on site is entirely sure what to make of."

"Forensic thaumaturgy," Devi suggests.

"Limited, unofficial scientific consultation," is how Henders puts it. "Cooperating with our inquiries."

"Like you can afford my consulting rate," says Devi. "I'm kidding."

Natalie asks, "What actually happened at Chedbury? What did they find? Did they raid the place? Did they find my sister?"

"Didn't say, ma'am," Henders says.

"If they'd found my sister, they've have said so, right?"

"I couldn't say."

"And they wouldn't need us there. Right?"

"I couldn't say."

You guys are good at this. "All right. We need a minute to grab equipment."

Devi's car, formerly parked not-quite-outside the Ferno residence, has been lightly torched and is missing a window. Still, its contents are pristine: an eclectic assortment of light-to-heavy aerospace engineering equipment. "Enough to do most jobs," he explains to Natalie, handing her a fistful of Kaprekar driver/linkers. "It'd be better if we could swing past work, but it's in the wrong direction. What are you bringing?"

Natalie indicates that all of her equipment amounts to a single earring. Empty fingers, bare wrists, nothing up her sleeves. "Theoretical physicist, remember? I can spell, but I don't practice."

"But you just cast that force field. 'Only one spell' my arse."

"Two spells. That and eset . Honest. In any case, I'm completely out of mana right now."

Devi raises one eyebrow, and once again draws his own conclusion. He hands her a plastic box containing the unscrewed pieces of his magic staff.

Natalie asks, "How long would it take you to put together a basic chi scanner? Something that can find my sister in a haystack."

Devi snorts. "Like, a hundred and fifty seconds."

"Good. Then I need something that can read people's True Names remotely."

Devi opens his mouth to respond to this, then closes it, and smiles. He has no idea how to do this. It is an old sensation, and a familiar one, and an exciting one.

"I can give you some pointers," Natalie suggests.

"I don't take dictation," Devi says. "I'm an engineer. You're the client. You give me requirements. I actualise."

*

They're in the back of the police car, headed west. The passenger compartment is roomy. Natalie shuffles uncomfortably in her seat, becoming a little carsick from facing the wrong way. Devi's on the other side, distracted by his engineering task, trying syllable sequences. There's a constant clattering of equipment. He looks like he's assembling a rifle.

"I don't believe in demons," he says.

Natalie looks at him, waiting for something else.

"I specifically don't believe in a demon called Ra," he continues. "...Which means I have a problem, because who blew the house up?"

"You heard the spell segment," Natalie says. "You heard the fellow's Name."

"Sure, but who was he? Who blows a house up? What is actually going on here? I feel like I'm coming in late. Like I missed acts one and two."

"You've got a monster in your basement," Natalie explains. "You've seen that physical things can come back from T-world. Would you believe that a mind can come back? Call it what you want. 'Hijacking'."

"But that wasn't Nick Laughon."

"Ra isn't one person," says Natalie.

"You mean, like... an organisation?"

Natalie doesn't say anything.

*

Chedbury Bridge Institute is its own private world, lurking behind tall electrified fences off an inaccessible road in the Chedbury forest. From the outside, none of its buildings are visible through the fence and trees, even in daylight. The track up to the entrance is not signposted. The Institute doesn't want to be found. There's work going on inside, and it would rather not be disturbed.

Devi and Natalie are driven straight in, indirectly revealing that any excitement occurring at this location, any kind of armed police raid, happened offscreen and is long since over. The Institute is four or five two-storey buildings made of stylishly modern sand-coloured bricks, almost new. It's close to midnight now, but all the exterior and interior lights are on. There are police all over, specialist vans and dogs, garbled radio chatter. An unusual number of men carry black rifles.

There's a weird cold atmosphere, an aftermath atmosphere.

Henders lets Devi and Natalie out. Devi's completed magic machine is quite heavy, six rings all on one wrist, some up to half a metre in diameter. They are kept from falling off by his staff, a conventional steel model, effective without being flashy. Devi turns the machine on using a long and slightly confused spell which clearly needs refactoring.

The first readings come in. Having lacked the time to build any kind of modulator, they come in through Devi's hand as inscrutable flux changes. He has to perform most of the decoding in his head. " Zui for you," he reports. "And thelet for me, we already knew that. No bindings for any of the cops. Just fuzz. Hah!"

Henders comes around and joins them after a brief conversation with the officer in charge of the site.

"When we arrived they were in the middle of tearing some machine down," he says. "Something they obviously wanted to hide. It's at the other end of the site." He nods at Devi's machine. "That thing's not going to break anything, is it? Not going to destroy any evidence?"

"Totally passive," Devi assures him cheerfully.

"Alright then. Stay behind me, please. No wandering off, no gawping."

He leads them on the most direct route possible, threading between the buildings and across darkened lawns with benches. At one point a windowless police van pulls away past them, out of a secondary car park towards the exit.

"That van has at least six passengers in it," Devi hisses, after aiming his machine at it. "Maybe seven or eight."

"You can't tell exactly how many?"

"I can't separate them. They're all Named ra ."

"Hmm."

"'Hmm'? This is what you mean by Ra being more than one person?"

"Ra was an accident," Natalie says. "Accidents happen. There's a lot of magic happening in the world, and it's only increasing. Why shouldn't an accident happen more than once? Mass-energy conservation may or may not be over. But a mind is just information, right? The integral of experience with respect to time. It's just a vector. There is no conservation law for information."

"So the Ra whom Laura's working with and the Ra who blew up her house were different people," Devi says.

"And the same person," Natalie says.

She shivers.

Around another corner, she catches sight of something. Inside another building, plainly visible through the windows, is a tall machine with a weird and serious familiarity to it.

It's a telescope, or at least derived from telescope ancestors. The main optical tube is about three metres long and seventy-five centimetres in diameter, polished black. Its range of motion is wrong. A full range of right ascension, but twice the usual declination, a feature useless to terrestrial telescopes. It is aimed down into the Earth at a steep angle, with the eyepiece only available from a raised platform. It's a shiny and new and highly specialised piece of equipment. Natalie looks carefully, and sees two cooperating oracles fitted over the end, designed to detect passing magical particles and transmute them into visible light in the most convenient available wavelengths.

"Chi astronomy," she breathes. Chis don't interact. You don't need to be on a high mountain in Chile, hundreds of miles away from light pollution sources, to study them. You can look right down through the Earth. You just need a quiet room with blackout curtains, and a mathematician for the servomotor firmware.

"No gawping," Henders calls.

This device reduces Natalie's experiments to cheap hack jobs. The Chedburians are ahead of her. She'd kill for their data.

*

They're brought to a large hall, a classic magical gymnasium with a standard D/E ring stencilled on its floor and modern adapters. Planted at most of the usual loci are the usual pieces for driving a Dehlavi lightning machine. The remaining pieces appear to have been abandoned in corners.

At the centre of the room are two empty hospital beds. They are aligned with two of the arms of the lightning Y which would be produced if the machine were active. There are medical monitoring machines-- additional consulting experts will be required to identify them, since neither mage is a medic. There are drips. Nutrients?

There are police investigators scattered around the room. Most of them look up expectantly as Devi and Natalie arrive.

Henders explains, "This is what they were tearing down. They seemed to be in a hurry. Look but don't touch."

"Who are 'they'?" Devi asks.

"The site staff. They're being questioned right now."

"Can we talk to them?" Natalie asks.

"No."

"How many people were here?" Devi asks. "It's the middle of the night. How many of them looked like scientists?"

Henders looks over at the ranking investigator in the room. "I don't have the whole list yet," the second man reports, "but seven people were in this room when we got here. Two in medical scrubs, five in casuals."

Devi says to Natalie, "To run a machine like this indefinitely, in shifts, allowing down time for a basic rate of mana recovery, and assuming fit mages--"

"Twenty-four to twenty-eight people, depending on their combined wattage," Natalie replies. The computation is trivial.

"This is a sleep science experiment," Devi announces. "You ever play Tetris for enough hours in one day that you end up dreaming in falling blocks? You ever study another language so hard that you end up dreaming in it? Mages have a similar thing, a specific trance state. We don't know a lot about it yet. With the right medical support, you could leave someone in that state for weeks. It looks like that's what they were doing."

"What about the patients?" Natalie demands. "What happened to the people in these beds?"

The second man, the investigator, shrugs. "They were empty when we got here. We're looking the rest of the site over now. You want us to bring a dog in?"

"Scanner," Natalie says to Devi, surgeon-style.

" Thelet eset oerin ," Devi answers, throwing her a decorated black iron ring, as big as a coaster. Natalie puts it to one eye and scans the figurative horizon. She sees familiar and unfamiliar magical equipment, most of it dormant. The telescope, obviously, and other machines, built in flexible layouts for experimentation. A funfair after hours.

If you know the conditions, you can repeat the same accident over and over, Natalie thinks. Why couldn't this whole place be staffed by Ra?

But then, why?

What does Laura have that Ra wants? What does she have access to that nobody else does?

At yet another end of the complex, locked in a windowless temperature-controlled storage room, is a brighter, fuzzier signal, clustered.

*

This Ra hears the voices on the other side of the door. The door is an almost-solid steel slab. It would be time-consuming to crack open, at least for the baseline police. But they have mages now, and he can hear their coded chatter. A familiar pair of Names.

This Ra resigns himself, because the deal is done. The launch is complete and the human weapons are away; there is more than one way to get into T-world, and there is more than one way to exit from its far end.

The storage room is cramped. Racks of shelves of chemical bottles line two walls, leaving a narrow chasm with just enough room for one of Ra and two bath-sized, thick-walled, blue PTFE tubs. Both tubs are too heavy when full for one man to move, and therefore had to be filled on the spot, one and then the other on top, hurriedly and clumsily. This Ra has spilled some of the hydrofluoric acid on himself, and will start to feel the burning and see the skin bubbling on his fingers very soon, but... The missiles are away and running, and in an ideal scenario this will be over in another day. If Laura Ferno is successful, she won't need a corporeal body to return to.

And in any case, there will always be more of him.

The wonderful thing about a bath of HF is that it'll take care of a mage and her tools at the same time. Precisely machined tools will stay in working condition for minutes or hours, but as time passes and acid dissolves the edges, they become less effective, and soon are damaged unrecoverably. The signal that Natalie Ferno and Anil Devi are tracking, which leads into the lower of the two baths, is clouding and smearing out, even as they brainstorm frantically on the other side of the door.

One of them pounds desperately on the door. "What have you done?" Natalie shouts. "I know you're in there! What have you done to my sister?"

Ra steps over to the door. "What we've done doesn't matter, Natalie," he says, peacefully.

"You've killed her," Natalie screams. "How can that not matter?"

"Because we're trying to end death," Ra tells her. "Don't you remember what I told you on that mountain? This is about freedom.

"We're trying to save the world."