When a man and his love interest first encounter one another in an adversarial setting, it's supposed to go like this: he proves overconfident; she proves overwhelmingly more competent; she decisively gets the better of him, with embarrassing and hilarious results; this impresses him (and anybody else who happens to be watching) while demonstrating that she's sassy and capable and can take care of herself.

But this is a little too early in the lives of Nick Laughon and Laura Ferno, and neither of them can really take care of themselves yet. It's their first year at university and it's their first Beginner's Bojutsu lesson. Every time she lands a blow on him they both drop their bo staffs, and every time he tries any kind of clever spinning move (while the instructor, who would disapprove, is not looking) he loses his grip and ends up hitting himself in the stomach. The whole lesson is awkward stances, heavily telegraphed moves and clumsy falls. Fortunately, stage one in any martial art is learning to take a fall. And stage two is learning to not feel like an idiot for falling down over and over again.

Nick has turned up for the class because a group of his friends have taken it up. After the end of the lesson, he invites Laura along to the pub with the rest of his gang. She, it transpires, has already been invited to the pub and is already coming along. In fact, she already knows everybody in the gang except Nick. This is because apart from Nick, all of them are thaumic engineering or theoretical magic students. They've all been taking elementary magic theory together for the last week and a half.

Huh.

So Nick, a mere English student, trails along behind their animated and highly technical conversation, listening in, bewildered. He watches Laura's bracelets jangle as she waves her hands around as she talks. She puzzles him. Most mages, including all of his mage friends, are male. And magic rings and the other small metallic tools of the mage's trade really are tools. Every mage he knows wears at most a few small rings hooked on a keyring or on a carabiner on a belt loop, with the rest in a rucksack or an actual toolbox. He's always thought of them as washers and gaskets and nuts and bolts. He's never considered them as jewellery.

It dawns on him why mages would be interested in bojutsu, and he feels stupid for missing it. Magic rings are less than half of the picture. A mage-in-training is a person who intends to spend most of his or her adult life waving a magic staff around for a living and a magic staff is a six-foot-long metal pole for propelling and coercing mana into the right shape.

Nick Laughon is 18, middle-sized, wavy-haired and fresh-faced. It's mid-evening in early autumn, hence dark and cold already, but he wears shorts in every weather and season. He cycles everywhere. When he's needed somewhere that's inaccessible on wheels, he runs there. Things that can't be run through, he climbs over. He is constantly reading and seemingly constantly eating, replenishing burnt energy; all of his books are full of dropped crumbs. He loves movies and music and beer and sport and learning new things that he didn't know before. He has almost no definition beyond what he loves. It's almost as if nothing bad has ever happened to him. His personality is pure, sharp and golden.

Laura Ferno is 18 and fiercely intelligent. When Nick pulls up a stool next to her and finds his way into her conversation, she gives him the impression of a girl caught at the instant of launching herself out of the starting blocks of her life. She intends to make history; she intends to learn literally everything there is to know about magic over the next three years, and then continue at the same pace of discovery for the rest of her life. Whether she has the talent to accomplish any such thing is not for Nick to judge, having known her for all of three hours, but she has determination and confidence. She talks at length about Montauk battery theory, magic-driven casting, the Three Open Problems and her mother, a gifted mage who taught Laura everything she knew. Laura has designs on the future.

So they drink Greene King IPA and gin and tonic respectively, while the evening and the conversation get comfortable and settle in for the long haul. It's the beginning of something, although it's not obvious to either of them that this is the beginning of anything. Later, she'll scale back her ambitions - a little - and he'll get a better grip on reality and how badly it sometimes works. And the relationship will grow patiently, like the good kind of record, the kind that doesn't sound good until the third or fourth listen. By the time either of them realises that they should have been counting from somewhere - Nick will realise first, but Laura will be the one who brings it up - neither of them will remember what day this was.

*

Precisely six months later they're in the pub again. Nick still hasn't succeeded in bringing Laura around to the real ale point of view. He'll eat or drink anything, regardless of what it used to be, what it was cooked in or whose plate it's on. People with the audacity to express preferences come off to him as wimps and he refuses to stop teasing Laura about her refusal to drink a real drink.

So it's the same two drinks, and so far tonight it's just the two of them; others may turn up but arrangements have been lazy and confused. In fact it's pretty much just the one of them. Nick feels like he's the only person who qualifies as "in attendance", because Laura's spent the last five minutes fiddling with the manual controls on the television mounted in the upper corner of the lounge, trying to find the channel showing today's Shuttle launch from Florida. She is maniacal about Shuttle launches. Today's has been relatively simple to catch, but NASA's operations adhere to no working day and even if they did it would be five hours removed from Laura's, so every few months she skips lectures or supervisions or bo lessons, stays up until two or gets up at four, whatever is necessary to be near a television at the right time.

"This is it," she says when she finds it, sitting back down and getting ready for the show, still not "in the room" in any real sense. There's no sound, but the rocket on the pad is visibly hissing with anticipation, venting steam and liquid oxygen vapour. The countdown is paused at T minus twenty minutes. It's a routine built-in hold. Laura has the whole sequence memorised from cryo tanking to MECO. If Nick watches her eyes carefully during the countdown, he can almost see the big banks of lights flicking from red to green.

"I still don't get it," Nick says. "Is this a magic thing? Isn't this the fiftieth Shuttle launch there's ever been and haven't you seen them all?"

"Fifty-six recorded, one in person, thirty-eight on live television," says Laura. "Soon to be thirty-nine. The full set."

"Is this a magic thing?"

"First-generation Shuttles predate any kind of serious magical modelling capability," says Laura, "so they left the whole technology on the shelf for safety reasons. They didn't understand it well enough back then. I mean, magic is pretty predictable now, because we have some solid theories about how magic moves and we have simulations that can model mana flow in three dimensions properly. But this was back in the late Seventies. It would stun you how low-tech these things are. You know how - you must know this - your wristwatch has a more powerful microprocessor in it than the Apollo Lunar Rover did?"

"My wristwatch, or any wristwatch? This is pretty sophisticated."

"I mean yours. Probably not so much an eight-quid Casio. But it's almost the same deal with Shuttle computers. You'd be stunned. But it makes sense because of how fanatical about safety you have to be when you fly space rockets with people on them. I think they have a saying, or if they don't have a saying then they should, which is 'If it ain't broke, fixing it can endanger the mission'. If it ain't broke, don't... don't kill people."

"Which is why there's a Space Shuttle II now," says Nick.

"Yesssss," says Laura. "Which is about ten percent lighter because of thaumic heat shielding, and also because it has ring-and-sigil attitude controls, and... a bunch of other stuff which they didn't want to retrofit into an existing orbiter."

"Has there been a Space Shuttle II launch yet, and if not..."

"Not for another few years," says Laura.

"...Are you going to watch those launches too?"

"I don't know," says Laura.

"You never answered my first question," says Nick.

"Which question?"

"My first question. Because space travel is cool and all, but you nearly missed an end-of-term exam last year."

Laura doesn't answer.

"Are you waiting for another Atlantis disaster? Because that was our generation's 'do you remember where you were' moment. You want to see a Shuttle blow up live?"

"No," says Laura, staring into her drink. And adds, "I've already seen that once." Here goes nothing, she thinks.

There's a pause.

"You saw the Atlantis disaster live?"

"Yeah."

"Wait, TV live or live live?"

"We were there," says Laura.

"You were there? You and your family?" Laura nods. "You were what, fourteen?" Another nod. "Wait. Wait." Nick realises there's something important here. He does some mental arithmetic.

Laura stares, holding her glass in both hands, eyes defocusing. She's been working up to telling him this for how long? And she still doesn't have more than the first few words worked out.

"Was that how your mother died?"

The countdown starts ticking again. Nineteen minutes, fifty-nine seconds.

"I don't know."

Fifty-eight. Fifty-seven. Fifty-six.

*

It's December 1993 and the Space Shuttle has never failed. As a super heavy lift launch system, the Shuttle program has a mind-boggling quoted probability-of-mission-failure figure of 1 in 60,000. The actual figure will later be discovered to have been closer to 1 in 60, with the difference made up by carelessness, lax safety culture and systematic managerial overconfidence. This overconfidence has arisen predominantly from the Shuttle's flawless track record. The Shuttle program is broken and unsafe. It is unsafe largely because everybody thinks it is safe. It is about to fail because it has never failed before. Tomorrow's headline will be: "LOST".

At 10:08:08 on 17 December, T+45.5 seconds into Shuttle mission STS-77, a large chunk of ice is pulled into Space Shuttle Atlantis' fuel system. The ice is there because the fuelling system was accidentally exposed to air while the External Tank was being filled. Two of the Shuttle's three main engines are destroyed instantly. The flight controller immediately orders "Abort RTLS", Return To Launch Site. At this point in the mission, Atlantis is still attached to two much larger Solid Rocket Boosters. Once triggered, SRBs cannot be shut off, so they are left to run out and detach as normal at T+123 seconds. Then the orbiter and External Tank, still mated to one another, pitch forward and fire their one remaining engine in the opposite direction, cancelling out their forward and upward velocity and accelerating back along the flight path. The plan is this: achieve a satisfactory course and trajectory back towards Florida; roll upright; disconnect the External Tank; and glide in to land at a dedicated landing strip at the launch site, which is ready for this exact eventuality. This is an insanely risky plan with many variables, chief of which being that whatever knocked out the first two SSMEs could imminently knock out the third. However, it is the best and only plan conceivable, and it has been prepared for. An RTLS has never happened before in reality, but it has happened ten thousand times in simulations: the pilot and six crew are as ready as any humans could ever be. If anything could work, this is it.

At T+181 seconds, Atlantis' last engine goes dark. A second piece of ice has been pulled into the turbopump system, which is now gutted and haemorrhaging liquid oxygen and hydrogen into clear air. The vehicle is 22 miles up and 31 miles downrange, still travelling directly away from its landing strip at well over a thousand miles per hour, upside down, with no motive power and freefalling like a thrown rock. The mission is now over. There are no more abort modes. There is no pulling out of the trajectory, no chance of crossing the ocean to a transatlantic abort site, and no crew bailout capability. In another minute, Atlantis will reach peak altitude. Around five minutes after that, it will crash into the Atlantic. Everybody on board will be killed. And everybody watching on the television and everybody listening on the radio and everybody watching from the ground is going to stand there while it happens. Except one.

"Doug," Rachel Ferno says to her husband, and surprises him by kissing him as he turns to look at her. "I love you," she says. " Kasta anh sukudat mirsii. Kids!"

"Rach, what are you--" Douglas Ferno begins, then stops, distracted, as the five pieces of Rachel's two-metre-long magic staff jump out of her rucksack and screw themselves together in mid-air. This apparently simple trick astounds him. He's seen his wife do a lot of magic, and he's seen the staff a million times, but he's never seen her assemble it except by hand, laboriously, taking at least a minute each time. He's a treasurer, no mage, but he knows that a spell like this takes about a month of writing and a month of practice, because of the laundry list of failure cases that have to be handled. How do the pieces know how to exit the rucksack? How do they pick a spot in the air to assemble at? How long should the assembled staff wait to be collected? What if there are only four pieces, what if half of them are stuck behind a wall?

Laura and Natalie are teenaged, and don't pick up on her urgency when Rachel hugs them both at once, one with each arm, and says "I love you," again. She tries to cover her bases by inflecting somewhere between "I love you: see you in a little while" and "I love you: goodbye forever". " Eset kasta oerinuum OOLO ," she adds, which starts her oxygen supply. It's not tuned properly: it blasts her hair downwards like an invisible localised hurricane. Her clothes flicker in the gale and the grass under her feet splays out in all directions. But there's no time for corrections. Here are the components that do matter: " Sedo oerinuum INKEH sedo MOMEH. Kasta esduq jachta! "

Douglas Ferno doesn't recognise the phrasing; the words just wash over him. Laura and Natalie fare worse. They have enough basic magical knowledge to understand that what their mother is doing is either nonsense, or so far beyond the modern magic state of the art that it might as well be... well, whatever comes next. Rachel Ferno has just initiated a pair of high-throughput transduction spells with almost fractal complexity. The patterns of mana radiating off her are incomprehensible. More than that, they're as bright as a sun. To a tuned mind, they're blinding. Who can handle spells that advanced? Who can imagine them?

Rachel Ferno's feet rise a few centimetres from the ground. She moves her hands around, something like sign language, distributing virtual controls to points in space where she can reach them. She's building a virtual cockpit. And she's just using hand signals and finger and thumb rings to do it. She's not even saying any words now. "Mum, what are you doing?" cries Laura. She and Natalie can now see luminous manifolds of mana closing up around their mother, like ornate armour.

Douglas Ferno can't: he reaches for his wife but is stopped by the invisible force field. "Rach, what's happening?" And he's right to be confused, because the smallest, simplest force fields in the world require a portable module the size of a motorcycle to project, and they categorically cannot be curved. Nothing she is doing is possible. "Rachel!"

Rachel reaches out with her right hand and collects her staff from where it was waiting, suspended in air. "Here goes nothing." As she touches it, there's a single pulse of real light, like a camera flash. Then she's airborne, following the exhaust trail out to sea and the plummeting orbiter.

*

Of course there are witnesses. It's impossible to watch a Shuttle launch from a good spot without company; the Fernos' spot is a crowded park in Titusville. That Rachel Ferno has disappeared, the police are prepared to believe. That she disappeared out at sea, during a Shuttle launch? The coastguard take the notification seriously and a search is begun. But even the people who watched it happen - even the people with photographic evidence - don't believe that she flew away.

A human being doesn't show up on radar. A human being in the air at 40 miles' range is too small a speck of dirt to show up on the video footage.

At T+318.9 the venting liquid oxygen and hydrogen finally ignite, blowing up the External Tank. The crew compartment of the orbiter survives the explosion and hits the Atlantic almost intact, though it and its occupants are pulverised on impact.

Seven bodies are recovered from the crash site by NASA.

*

(Nine minutes.)

"That's it?"

Laura shrugs.

"So what happened? ...Laura, what happened?"

"We don't know! We stayed in Florida for a month, waiting for information. And they never found her. The police, the coastguard, NASA. If NASA were looking for an eighth body, which is doubtful. We don't know what happened. We don't know for sure that she tried to save the Shuttle. We don't even know if she's actually dead. She's been missing for... well, not long enough. In another few years we can declare her legally dead. Does that answer your question?"

"Christ," says Nick, and takes another long pull from his pint while he thinks. And once he's done that, he says, "No. It doesn't.

"You loved your mum. But when you talk about her she always sounds as if she was half-teacher and half-rival. She taught you everything you know about magic - you and Natalie - and you were well on your way to catching up with her and then eventually surpassing her. No problem. Then just at the moment when you were starting to be a real match for her, she pulled the rug out from under you both. She did seven or eight completely impossible things right in front of you, things which she had never bothered to try to explain were possible, and then she flew away without telling you what she'd done or how she'd done it. She left you with no idea how much else she was holding back, or even who she actually was, because in that last second, she--"

"It was like she'd dropped the mask of mum-slash-wife," says Laura. "'This is who I really am. I'm a fucking Titan, I'm a cloaked thaumic witch-goddess and I can do anything. Goodbye.'"

"She was like an actual magician--"

"--never revealed her secrets," says Laura. "That interpretation had occurred to me too. But - and I'm sure I've covered this - magic is the worst-named field of science in the world. It was a lousy, stupid nickname for some genuinely new physics, and it stuck, and now everybody hates the man who coined it. Including himself. Magic isn't magic. It is a field of science. You do not sit on results. Not results like that."

"So you don't follow the launches because you're scared of another launch failure and want to be the one who stops them from happening," says Nick.

"No."

"And you don't follow them because you miss her."

"No."

"Although you do miss her."

"I do."

"And you definitely don't secretly want to be like your mother."

"God, no."

"So I don't get it. She made you angry. This is nothing but a big bad memory. What do you want?"

"...What I want is for us to go into space right now," says Laura. She takes off a few bangles and spins them idly between her fingers. "Just us two. We could walk out the door and it would take about ten minutes to get there, straight up. I just need the right words to say. I want autokinetics, air UI, the fluid pump spell she used for O 2 , non-vocal casting, DWIM, dynamic shielding, and whatever it is she used for a mana source. To begin with. I want it all and I want to be the first person to go into space without a vehicle. Today, if possible. And more after that.

"Magic's not the Force. It's not mystical, it's a gauge theory. It explains observations. It is, at its root, a collection of dry and unpalatable nonlinear partial differential equations which are known to be not totally accurate. Magic does not speak to us or obey our commands. Getting magic to do anything, let alone what you want it to do, is close to impossible without insanely complex equipment. The equipment itself couldn't be built prior to around 1981, and prior to 1990 computer-aided design and manufacture weren't sophisticated enough. That's to say nothing of the mental gymnastics. You know that people on my course are supposed to spend at least twelve hours a week meditating?"

Nick does know this. He also knows that Laura gets away with less.

"Magic is difficult," she continues. "It's harsh and expensive and obtuse. Magic isn't magic."

"...But it should be," Nick concludes.

"Yeah."

"It's not likely to happen today, Laura."

"This week, then."

Nick shakes his head. Laura shakes her head too. She knows what she's asking for.

Their glasses are both empty. "Another?" Nick asks.

"In a minute," Laura says, pointing.

On the television screen, because she knows what to look for, Laura can see the launch pad sound suppression system activating, dumping a thousand tonnes of water onto the pad just before liftoff in order to protect the orbiter from acoustic damage. In the pit underneath the Shuttle's engines, a shower of red sparks erupts, burning off any lingering pockets of flammable hydrogen before the engines themselves fire. In the absence of an on-screen timer or an audible commentator, Laura is counting to herself:

"Nine. Eight. Main engine start--"

They start, all three of them, bright red at first, then white, then ramping up in a matter of seconds to a temperature where the hottest part of the flame isn't visible. The whole launch stack pitches forward slightly, reacting to the off-centre thrust, then gently leans back towards vertical. All that's left now is for the SRBs to ignite. "Four. Three. Two. One."