Starfire

6

Celine was used to kisses. She had spent her teenage years in the Philippines and traveled widely in Europe and the Middle East. In many nations of the world she knew that an embrace or a kiss on the cheek was as natural as a handshake.

Less common — unique, in fact, in Celine’s experience — was the visitor who strode across the Oval Office, grabbed you in a bear hug, and gave you a great smacking kiss on the lips.

But that was Wilmer. He had acknowledged few of the rules of polite society when he and Celine were partners on the Mars expedition, and in the twenty-seven years since, he had apparently changed not at all.

Celine kissed him back, just as heartily. Lovers, even long-ago and faraway lovers, possess privileges denied to others. After a couple of seconds she pushed him away and held him at arm’s length. “Wilmer Oldfield, you’re as handsome and debonair as ever.” His head, close to bald, wore its remaining hair close-cropped, and his idea of suitable White House dress was a faded brown shirt and pants short enough to show two inches of white socks.

“Now you must introduce me,” Celine went on.

She had glimpsed the woman walking in behind Wilmer in the moment before she was grabbed and hugged. She made a more detailed survey now. The other visitor was short and broad and very black, with clear, shiny skin. She wore a tiny skirt of bright lime green and a yellow sleeveless top that showed off muscular limbs. Her hair was shaped into an array of jutting black spikes that suggested to Celine’s eye an electrocuted cartoon character.

Wilmer’s companion was in her mid-twenties. She appeared subdued and upset at the same time. “Celine,” Wilmer said, “this here’s my friend Star Vjansander. Star, this here’s Celine Tanaka.” He added, as an afterthought, “The President of the United States.”

The woman bobbed her head. “Pleased t’ meet yer, mam. I’m actually Astarte Vjansander; but if you want ter call me Star, like Wilmer does, that’s all right.”

The accent was unfamiliar. A broadness to the vowels, plus the occasional ter for to, and yer for you. Celine wondered if that was typical North Australian, and decided that she rather liked it. More familiar was the look that Astarte Vjansander gave Wilmer. Celine recognized it at once as adoration, though it was unlikely that Wilmer did. But it accounted for Astarte’s discomfort when she saw the other two kissing. Had Wilmer bothered to mention that he and Celine had been an intimate item in the remote past, although there had been nothing more than platonic friendship for many years?

Probably not. It wasn’t the sort of thing that would occur to him.

And was it a sexual relationship between Wilmer and Astarte? Probably, in spite of the big age difference. Wilmer might collect his female partners in a bemused and abstracted way, but he certainly collected them. Celine sensed her own objection to the idea that Wilmer and Astarte were lovers, at the same time as she was astonished by her reaction. If she didn’t like to share Wilmer when he had not been part of her love life for a full quarter of a century, then no wonder Astarte was jealous. Humans were inexplicable only if you assumed that they were logical.

She smiled at the young woman, offering nonverbal reassurance that she had no territorial claims on Wilmer. But it was a waste of time, because before she could get onto Astarte’s wavelength Wilmer was off and running.

“We probably sounded a bit mysterious to your lady in the outside office, insisting we had to see you in person and not telling her why. But you see, I didn’t want to put her in a panic or have her spreading bad rumors.”

“Given some of the things that Claudette has heard in the past few years, I don’t think you need to worry. It would take news of the end of the world to shake her.”

As a light remark, it fell flat. Astarte gasped and turned to Wilmer.

“She knows.”

“No, she don’t. Go on, Star, you tell it. It’s your story. I mostly came to get you in to meet Celine.”

Astarte nodded, but she didn’t say a word. Celine had seen the same thing often enough in the past. People entered the office with their story carefully prepared, and promptly became tongue-tied in her presence. After the first few times she realized that it had nothing to do with her. It was the office of the presidency, carrying a weight unrelated to the personality and character of its current occupant. The surprise was that Astarte Vjansander felt it.

Celine said, “Let’s all sit down and make ourselves comfortable. And Wilmer, why don’t you start instead of Star? You’ve briefed me often enough, you know how to keep it down to my level.”

She was making a trade-off. Wilmer must certainly know whatever it was that Astarte Vjansander wanted to say, otherwise he would never have brought her to meet Celine.

On the other hand, Wilmer’s briefings had their own problems. Clarity, yes. Brevity, never. Celine sat back and prepared for a long evening.

“Is that all right with you, Star?” Wilmer said. And, at her nod, “You take over whenever you feel like it.” He put his hand to the top of his bald head and rubbed at it for inspiration. “I -think I’d better go a fair way back. Celine, you know how I told you there was something odd about the Alpha Centauri supernova, right from the beginning?”

“Told me once, told me twice, told me a hundred times. You may not remember this, but when we had our first look at the supernova, back on the Schiaparelli, you said that Alpha Centauri was a double star system, and double stars can become Type Ia supernovas only if one of the pair is a white dwarf. And Alpha Centauri didn’t qualify.”

“Still doesn’t,” Wilmer said placidly. “Bit of a nuisance, really, since the thing did go supernova. Zoe Nash told me then that if that’s what the astrophysicists’ theories said, we damn well better get new theories. She was right, of course. Poor old Zoe.” He stared off at nothing for a few seconds, then shook his head. “Anyway, I worked and worked trying to explain the Alpha C supernova. And I got nowhere.”

Celine could imagine what lay behind those simple words. When Wilmer latched on to a question he was a bulldog, worrying at the problem endlessly. He had picked up and solved many other problems during the past quarter of a century, but she suspected that there had never been a waking moment when the mystery of the supernova was fully out of his mind.

Wilmer wouldn’t have had much help, either. Since the supernova, human survival and planetary rebuilding had been the sole priorities. There had been no spare money or resources for pure research, and you met few young physicists.

“You had no theory?” she asked, when neither Wilmer nor Astarte seemed ready to speak.

“Worse than that. I had a dozen.” Wilmer blinked at Celine. He was almost sixty, yet his eyes still had the clear innocence of a young child. “A few of the ideas were beauts, too. You could go to bed with ’em at night, and still be in love when you woke up in the morning. But you know what they say, a beautiful theory gets destroyed by one ugly fact. I could make up all sorts of mechanisms that might let Alpha C go supernova. I could even make my models match bits and pieces of the data. Sometimes I fitted the recorded light curves, or maybe the neutrino arrival pattern, and a few times I got the gamma pulse profile. What I couldn’t do was find a theory that would match all the data at once. Which means, when you get right down to it, that I didn’t have a theory at all. That’s where it stood for all those years. And that’s where it stood four months ago, when Star came to see me.”

He beamed at his young companion. She smiled back, a quick flash of crooked white teeth, but she ducked her head when she saw Celine was watching.

“Would you like something?” Celine asked. What she had in mind was a low-level fizz, something to calm Astarte and make her feel more at ease. All the while that Wilmer had been speaking, the young visitor had fidgeted on the edge of her chair.

“Yes, mam.” Astarte gave another wriggle, but still she didn’t look at Celine. “Mam, I’d like ter go ter the bathroom. In fact, I have ter, right this minute, or I’ll pee on the chair.”

“Last person to do that was probably Calvin Coolidge,” Celine said. She wondered if Astarte heard her, because as soon as she added, “Private facility through that door, help yourself,” Star was off, vanishing into the bathroom.

“Ta, mam,” she said as the door closed.

“Nerves,” Wilmer said. “She’ll get over it. If it’s all right with you, we’ll wait ’til she comes back so she can hear everything and join in when she feels ready. Star’s not normally like this. You’ll see, she’ll perk up.”

“We’ll wait for her. I’ve got nothing to do.”

Wilmer nodded. Irony was wasted on him, or possibly he found it reasonable that the President of the United States had lots of free time. Celine looked for a tactful way to phrase her next remark — though tact, like irony, was alien to Wilmer.

“Astarte doesn’t seem like one of your usual colleagues.”

“She’s not. She’s a damn sight smarter. Smarter than them, smarter than me.”

At Celine’s skeptical glance, he added, “She is, you know. I’m sure of it, but most people can’t recognize that because the way she does things is so off the wall. You’ll see it when she’s at ease and can relax a bit. It’s her first time north of the line, too, so she’s nervous. When she feels at home she can get a bit crude. Some of the people at the New Sydney institute say she needs to be house-broken.”

“I can understand anyone’s feeling strange the first time they’re in this office. I know I was.” It seemed to Celine that Astarte Vjansander was already quite as crude as she needed to be. As for her talents, Celine would reserve judgment — although Wilmer was not one to underrate his abilities. “How did you find her?”

“I didn’t. She found me. Star thinks she’s twenty-four, but she’s not sure. She’s had a hell of a life. She was born in what used to be the Northern Territory, a few years after Alpha C, when the whole of Australia was still a wreck. She doesn’t know who her parents were, but she reckons they have to be dead. She was about seven years old, living in the middle of nowhere, when the Vjansander party found her during the first post-supernova survey. She ate bugs and little lizards and crocodile eggs and anything else she could find. She could speak some, which is pretty much a miracle, considering there was nobody else around. She didn’t know her name.”

“So where did she learn science?”

“Beats me. Breathed it in through her skin, I guess. Things in science that the average twelve-year-old would know, she’s never heard of. But she finds other ways. I don’t believe she works in words at all; it’s pictures and equations. After she arrived at the institute, at the first seminar that I took her to—”

“Later,” Celine said quietly. She hoped that the housebroken remark was not to be taken literally, because the bathroom door was opening. “Everything all right, Star?”

“Real good.” Astarte gave Celine her first full smile, and she seemed like a different person. “There’s nothing beats a pee, is there, when yer really have ter go? I feel loads better.”

“Like to take over, then?” Wilmer asked. “It’s your theory.”

“That’s all right.” Star went to her chair, staring at it before she sat down. “Did that Coolidge fella yer talked about really sit here and unload?”

“I doubt it.” Celine laughed. “But who knows? Silent Cal, they called him. He’d never have admitted it.” The meeting was taking a downward turn. “Wilmer? Where were we when you stopped?”

“I said I was churning out supernova theories by the cartload, and all of them crashed when I compared them with experiment. I showed ’em to Star in the first month after she came to New Sydney. She agreed they were all junk. Data rules. Theories have to fit observations, not the other way round. So I thought that was the end of it.”

Wilmer paused again, looking right past Celine and frowning at the wall of the office.

“But it wasn’t?” she prompted.

“For a long time I wasn’t sure. Star came to me with something new, but it made me real uncomfortable. Right, Star?”

She nodded. “He told me that I knew bugger-all about how to prove things, an’ all I was doing was making wild-arse guesses. And he told me if I kept dropping monkey-nut shells on the floor where he stepped on ’em in his bare feet, I’d get a boot up the wazoo and be out of there so quick I wouldn’t know where I was ’til I landed.”

Celine decided that she might as well relax. This meeting would go at its own pace, regardless of her preferences. “Still works barefoot, does he?” she said. “I used to tell him he only did it in case he ever needed to count to more than ten.”

Astarte hooted, and Wilmer said mildly, “Star still doesn’t know how to prove things, and she’s a bugger to have around the house because she never cleans up. But she’s infernal good at guessing. And there are great ideas that just can’t be proved until long after they’re discovered. Remember Max Planck.”

“The physicist?” Celine did remember Max Planck, but Wilmer had lost her. “Planck, like in Planck’s constant and the Planck length?”

“That’s him. A hundred and fifty years ago, there was a problem in physics that had everybody baffled. When you worked out the formula for how much energy should radiate from a closed box, you found that at short wavelengths the calculated value went to infinity. In the real world that obviously wasn’t the case. And data rules, theory only serves. But people who looked at the analysis all agreed with the results, and they were some of the best minds of the time — men like Rayleigh and Jeans and Boltzmann.

“So there was a big problem, and no solution. Then in 1900 Max Planck showed that if you used a trick, you could get a curve that fitted the experiments for all wavelengths. It was a really odd trick, because to get the right answer you had to use a formula that would apply only if the energy radiating out of the box came in little discrete packages. Planck gave the package a name, a quantum, and he could calculate how big each quantum had to be. He found that it involved a new constant. Planck’s constant.”

“Wilmer, I heard all this thirty-odd years ago, and then I forgot it. Do I really need to hear it again?”

His high forehead furrowed. “Yeah. Of course you do. Otherwise I wouldn’t be saying it, would I?”

“Go on, then.” Celine had forgotten how impervious Wilmer was to distractions. “Just keep in mind that we can go to dinner as soon as we feel ready to eat it.”

“I’m ready now. I’ll speed up a bit. Everybody thought that what Planck did in 1900 was a mathematical trick, that it didn’t mean squat in the real world. Energy couldn’t really come in little bundles. Even if the method worked for some reason when you were dealing with radiation from a closed box, that wasn’t the way the rest of the world operated.

“But then Einstein took what Max Planck had done at face value. He explained the photoelectric effect by saying that light, and all radiation, interacted with matter as though the light was made up of quanta. If a quantum had enough energy, it would jar an electron loose from a surface that the light hit. If it didn’t have enough energy — if the wavelength of the light was too long — then no matter how intense the beam of light, there would be no release of electrons.”

“I’ve heard that before, too, and I’m getting hungry. Wilmer, what’s your point?”

“It’s this. Star made an assumption. We can go into details about what it is later; all I need to say at the moment is that it’s the same order of assumption that Planck made in 1900. Radical, and simple, and enough to make you drop your back teeth. Star can’t give you a justification for it, and neither can I, any more than Max Planck could. But with that assumption, and with nothing else that I didn’t already have in my theories, Star matched the recorded light curves from Alpha C, and the neutrino arrival pattern, and the gamma pulse profile. The lot, all at once, which was something I had never been able to do. And it’s something I would never have been able to do, nor would anyone else, if Star hadn’t made that leap of intuition.”

“That’s great.” Celine looked from Wilmer to Astarte, who was now basking in Wilmer’s praise. “I believe you, and I think it’s wonderful for both of you. And I’m glad to see you, Wilmer, anytime. But I don’t see why you had to come running over here to tell me this when you could just as easily have called.”

But did she know, or at least suspect? Celine recalled Astarte’s gasp when she mentioned the imminent end of the world. The bad thing about being a world-class worrier was that being right was worse than being wrong.

“No,” Wilmer said. “We absolutely had to come, as soon as we finished checking the calculations. Star’s theory says that one component of the particle flux released at the time of the supernova ought to be traveling a lot faster than the old theories predicted. So we have less time than we expected.”

Celine’s mind ran ahead, wondering about the rest of it. “When?”

“We’re not absolutely sure. We need the latest Sniffer data to determine accurate dates, and we don’t have it. Can you get that for us?”

“Yes. When will all this happen?”

“A big slug of particles could be here soon.”

“When?”

“Real soon. Months, maybe even weeks.” Wilmer leaned back and told Celine something she already knew better than he did. “Trouble is, the space shield you’re building can’t possibly be ready.”

Wilmer and Astarte added to Celine’s problems during dinner.

Meals were not optional events for Celine, even if the sky was falling. She had learned something during the disastrous return of the Mars expedition to Earth: Even when you were worried sick, even when you had zero appetite, even when you were so depressed that food felt like it stuck in your gullet, you had to eat.

First, though, Nick Lopez needed to know that the World Protection Federation — and the world — was in for bad news. Celine tried a quick call while Star went out to collect her and Wilmer’s luggage. The call turned out to be a wasted effort. On a planet where everyone could supposedly be reached at any time, Lopez did not answer. His whereabouts were stated as “unknown” by the staff of the World Protection Federation.

Celine didn’t believe that for a moment. They knew, but they weren’t telling. She left a message saying that she and Nick needed to talk on an urgent matter. After a moment she added the words highly sensitive. That ought to tickle Nick’s political curiosity.

As soon as Astarte had their luggage she would be conducted by the White House staff to the private dining room, where their meal should be waiting. As Celine and Wilmer headed that way she asked him how he had first heard of Astarte Vjansander.

“Out of the blue,” he said. “One day, five months ago, I got this package from the convent at Weipa, way up north on Albatross Bay.”

“You mean Star is a nun}”

“Gawdelpus, no. If Star’s a nun, Madame Curie ran a whorehouse. Star lived in the wild; she just used the convent as a mailing address and a place to beg free meals. Anyway, the envelope I received was full of pages of equations and drawings, all hand-written. I recognized the name Vjansander, it’s common in the territory, but I drew a blank with the name Astarte. At first I thought it had to be a man, because if a woman was given a name that sounded like ass and tarty put together, she’d change it soon as she could. Then during the tea break I found that Maria Greene and old Herbert Westerly had received copies of the same thing I had — all hand-written, must have taken ages. They’d looked at a few pages and found no sign of a proof for anything, so they’d chucked out the whole mess. I went back to my room, ready to follow their example, because there’s more nuts in the world than you can believe. It’s always the same old story: Einstein was wrong, Dirac didn’t understand what he was doing, Feynman was too simpleminded, Gottlieb missed the point. See, they always go after the big game in physics, and their own alternative ideas are always gibberish. It’s like Pauli says, most of the theories are so bad they’re not even wrong.”

They had reached the dining room and Astarte was not yet there. Celine walked over to the window and stared out at the night sky, looking to where Sky City would be, as Wilmer went on: “So I was all set to dump the papers into the trash. But I riffled through as I was ready to drop ’em, and I saw equations that I recognized at the bottom of a couple of the pages. One was the Klein-Nishina scattering formula, and the other was an old equation for something called an Emden polytrope, in an odd notation. That said we were in Eddington country. But the thing that struck me about what I was looking at wasn’t that those were new results — they were old, both of ’em — but that they were detailed. People with half-assed ideas always go grandiose, and they start by throwing overboard things like relativity or the conservation of energy. No sign of that here.

“So I glanced at a couple more pages and I saw variations on more things I recognized, like nucleosynthesis and stellar structure and stability. That’s when I cleared my desk, put my head down, and took a real good look.”

Celine could imagine what that meant. Wilmer had more sitzfleisch than a tired camel, more stamina than anyone in the world to sit in one place and worry at a problem while the seasons changed around him. He would remain at his desk forever, his high forehead with its heavy brow ridges scowling at nothing while his mind bludgeoned Nature into revealing its secrets.

“And I decided that whoever sent me the stuff wasn’t a nutcase at all,” Wilmer concluded. “Some of the ideas still seemed crazy, some I felt sure were dead wrong, a few I could see ways maybe to improve. But I knew I’d have to talk to the feller first and make sure I was reading him right. So I headed up-country to look for him. And I found Star. And I brought her back to the institute. I got her a staff position.”

A staff position, when there was precious little money for anything and none for theoretical physicists. Of course. As simple as that — if you were Wilmer Oldfield and you paid no attention to obstacles.

“She didn’t really live in the wild, did she?”

“She said she didn’t. I think she did, though, and I bet you would, too.” Wilmer turned away from the window and went to help himself to the stuffed celery sticks. “They do you well here,” he said with his mouth full. “Maybe it’s not all that bad being President. Anyway, Star had a little one-roomer at the edge of a wet-weather creek. Outside fireplace. No plumbing. No crapper. You want to take a dump, you do it out in the bush like the animals, and hope there’s no saltwater croc around to take a bite out of your arse. No electronics, of course, so no reference service or webwalks. Star had a couple dozen physics and astronomy books, all pre-Alpha C. She wouldn’t tell me where she got ’em — pinched ’em, for a guess — and a big slate board for writing down results. Not much used. She does analysis mostly in her head, like me. Saves on chalk.”

“So what was the big new idea she had?” Celine asked. “Even if it’s hard to understand, you have to be able to explain it to me. If I don’t get it, I guarantee that not many others around here will.”

“Best you ask Star about that.” Wilmer paused in his steady munching. “You give her a drink or two, get her loosened up, and she’ll talk. Do I hear her clogs out there? What’s she doing?”

The footsteps on the hard polished floor of the corridor had an odd cadence. They clopped forward half a dozen paces, paused for five seconds, advanced, and paused again.

“I think she’s looking at the pictures,” Celine said. “It’s a portrait gallery of the Presidents.” She suspected from Wilmer’s expression that he had walked along the same corridor three minutes earlier and never noticed the walls at all. She moved across to the side table and said as Star came in, “Here you are. How about a drink, then?”

“Yer better believe it.” Astarte was carrying a single bag. Like Wilmer, she apparently believed in traveling light — the travel bag was for both of them. She walked forward to the table, picked up a bottle of vodka, and sniffed at it. As she poured two tumblersful she said, “Lot of ugly old buggers out there in the hall. Yer the only woman, and the only one of the whole lot who looks halfway human.”

If you tried really hard, you could take that as a compliment. Celine pointed to the ice bucket as Astarte handed one of the tumblers to Wilmer. Star shook her head. “Dilutes the goodness out.” She raised her glass, took a big gulp, and breathed in deeply through her nose. “Not bad. Better than at the convent. Tastes a bit turpid, though. D’yer make it yerself?”

“In the basement,” Celine said, and saw Star’s accepting nod. Another joke fallen down dead. She made a decision and poured herself a glass of chilled white wine. In politics it often helped to be the only one sober, but tonight was not politics.

Though what it was, Celine was not sure. Not the end of the world, but perhaps the beginning of the end?

“Come and sit. down.” She nodded at the server, and it began to rotate the loaded tureens slowly to each place.

Astarte brought her tumbler and the bottle with her, set them down in front of her, and watched the action of the server. “Smart little bugger,” she said after a while. The server was pausing only at places where someone was sitting. “How’s it know where we are?”

“Thermal sensor. Help yourself.”

“Yeah. We do it that way at the convent in Weipa. Only they got people to serve food for yer at Wilmer’s institute, so yer feel yer can’t take too much. How come yer don’t get served by people? Yer the President.”

“People talk more freely if there’s no one else listening.” Which was a totally bogus explanation, since Celine knew that the whole meeting was being recorded. “Just take what you want from any dish.”

“And you use a knife and fork, Star,” Wilmer added. “Same as at the institute. Or you’ll be in trouble.”

Astarte glared at him, but she nodded. She piled her plate high with meat and shrimp, ignoring all forms of vegetable. Wilmer took his turn and helped himself to a ton of everything. As he was doing so Astarte drained her glass and refilled it to the brim from the bottle of vodka.

“No worries.” Wilmer noticed Celine’s dubious look. “Star’s got a hollow leg. She’ll drink you and me under the table and then go back to work on her physics. How about a bit of chat from you, Star? I bring you all this way, and we don’t get a peep out of you. What’s Celine here going to think?”

“All right.” In spite of Wilmer’s warning Astarte was holding three large shrimp in her left hand and a juicy veal chop in her right. “What yer want me ter say?”

“It’s your theory, girl. Talk about it.”

“What about my food?”

“It can wait. We’re not going to pinch it.”

Celine added, “If you like, we can warm it for you later.”

“Oh, all right.” Astarte reluctantly put down the veal chop and the shrimp and wiped her hands on the sides of her sleeveless top. “A supernova’s — mmm — just one form of stellar — mmm — instability.”

“Chew and swallow first.” Wilmer turned to Celine. “I can’t take her anywhere. She does that all the time. You’d think she was a pelican the way she packs food into her mouth.”

Star grinned at Celine, a round-cheeked chipmunk smile, chewed, swallowed, and finally said, “He’s always on at me, but he’s all right otherwise. Let’s start with a question: When is a star unstable? Wilmer proved that yer can’t make Alpha Centauri go supernova if you work with the usual theories and continuous variables. But it did. Once you accept that, then yer have ter ask, can yer do it with discontinuous variables? Things that act like an impulse. You know what an impulse is, do you?”

“Assume I do.” Once, in the distant past, Celine had possessed a first-rate technical training. The question was, how much of it remained?

“There’s a few different ways to drive a star toward instability,” Astarte went on. “One is, you load on mass from outside until all of a sudden you have a collapse and an explosion. Another is you run out of raw material for fusion, an’ again you get a collapse an’ explosion. But those don’t work for Alpha Centauri; Wilmer proved that. So I asked myself, is there another way to cause instability, using some kind of impulsive events?

“Well, there is. Yer take a star — an’ it don’t have ter be the usual sort of star for a supernova. I mean, it don’t have to be a binary with one dwarf component, or a star many times as massive as the Sun. It can be any old star, could even be Sol. There’s something for yer to think about. So you take this star, an’ you apply a compressive pulse. A bit of a squeeze, and it don’t have to be a big squeeze, either. Yer can do it asymmetric, like on opposite poles, or you can make it work with radial squeezes, too, toward the center. Either way, yer can calculate the modes of oscillation.”

“You mean you can.”

“Yeah. Me and Wilmer.” Astarte picked up a shrimp, stared at it longingly, then put it down. “A star is stable because there’s a balance everywhere inside it between gravitational force inward and radiation pressure outward. So the star reacts ter the squeeze by contracting a bit, then the radiation pressure takes hold and pushes it back out. It overshoots a little bit, comes out a bit farther than it was ter start with, and oscillates. For some stars, like Cepheid variables, the wobble occurs naturally. But for most stars the oscillation will damp out — unless, just at the right moment, yer hit it again with another compressive pulse. And then you hit it again, and again, doing it each time at just the right moment. Then the oscillations don’t damp out at all. Yer get resonance.”

“Like soldiers,” Celine said, “marching over a bridge. They’re supposed to break step and not march together, otherwise the regular rhythm of their marching could hit the resonant frequency of the bridge and make it collapse.”

“I didn’t hear about that!” Star’s eyes widened with pleasure. “I love it. Have yer seen it happen?”

“No. Actually, I’m not sure it ever has. But people talk about it all the time as if it’s true.”

“Yer could do it. You’re the President, you’re in charge of the Army. Yer could take a whole bunch of troops, and a bridge, and tell ’em ter march over and not break step and see what happens.”

“Not if I want to stay President I couldn’t,” Celine said, and Wilmer added, “Star, unless I hear more astrophysics I’ll take that bottle away.”

“First yer tell me ter talk, and then when I’m talking you complain.” Astarte turned to Celine. “Anyway, an oscillating star’s not quite like troops walking over a bridge. It’s more like a pendulum, where if yer give it a bit of a nudge on each swing, the size of the swing gets bigger and bigger each time. But all of a sudden, instead of swinging back, the pendulum changes the way it moves.” Star made a complete revolution with her arm. “It goes right over the top and comes down on the other side. That’s what it does if it’s a pendulum. If it’s a star, it goes supernova. Like Alpha Centauri went supernova. Got it?”

“I think so.” Celine had been expecting something far more complicated, and this seemed remarkably clear and simple. “The star experiences a small impulsive force, applied regularly.”

“No.” Star scowled. “Maybe I shouldn’t have used the pendulum idea. Yer can’t hit a star with a regular squeeze, you have ter do it at intervals that vary with time, or it won’t work — and calculating the times gave us no end of trouble.”

“But the principle’s the same, isn’t it?” Celine was reluctant to abandon her nice mental picture. “I mean, instead of coming regularly, the squeezes come at certain calculated times. And if that goes on long enough, the whole star becomes unstable.”

“It does indeed,” Wilmer said, and Star added, “Becomes unstable, and explodes like a son of a bitch.”

“That makes perfect sense.” But Celine suspected that she was still missing something. “Why did you think I would find it hard to accept?”

“Not that part,” said Wilmer. “I felt sure you’d accept everything so far.”

“So what else is there?” Celine looked from Wilmer to Astarte, who had bent low over her plate, grabbed her veal chop in both hands, and was tearing a big piece off it with those crooked white teeth. “What haven’t you told me?”

Astarte stared at her silently over the lump of bloody meat and went on chewing steadily.

“We haven’t told you the part that’s hard to accept,” Wilmer said. “The oscillatory squeeze process that Star describes works perfectly. It allows us to reproduce every measurement that we’ve made since the beginning of the Alpha C supernova. But there’s something we’ve not discussed.”

He deliberately waited, until Celine said, “What?” She had a hollow feeling in the pit of her stomach, as if her worry button had just been pressed.

“The agent. What is it that can impose such a systematic, exactly timed compressive pulse on a whole star?”

“You mean, what physical process can produce that effect?”

“I wish I meant that, but I don’t.” Wilmer seemed upset, and to Celine that was a bad sign. Wilmer never became uncomfortable when physics was the subject. “We’ve racked our brains, Star and me, trying to come up with a natural explanation for what happened. And we can’t. The timing-sequence of the impulses needed to make Alpha C go pop is so peculiar and improbable, I don’t see how it could possibly arise naturally. Something or somebody produced that sequence by design. Something made that star system go supernova.”

While Celine stared in disbelief, Astarte said, “Tell her the rest. About the gamma pulse and the particle storm.”

“Oh, yes.” Wilmer rubbed the bald patch on the top of his head — already red and inflamed from his previous attentions. “It turns out that the right sequence of impulsive compressions needed to provide a supernova is not radially symmetrical. Certain modes of oscillation must be excited, and that in turn gives preferred directions of emission for gamma rays and for the charged particle beam. Everyone always assumed that the fact that the gamma-ray beam was aimed to hit Earth, twenty-seven years ago, was a piece of pure bad luck.”

“Wasn’t it?” Celine was wondering if she could ever explain to anyone else what Wilmer and Astarte had been saying. Not one of her colleagues had any previous experience with Wilmer, or understood his brilliance and intellectual honesty.

“It wasn’t bad luck,” Wilmer said, and Astarte nodded firmly.

“Calculations show that it can’t be an accident,” she added. “Yer see, the Sun moves at thirty-two kilometers a second relative ter Alpha Centauri. Ter have a narrow gamma-ray beam intersect the position of Sol, twenty-seven years ago, and then ter have the main front of the particle storm hit Sol again, in its new position tens of billions of kilometers away — that’s off the scale on the probability charts.

“Something made Alpha Centauri go supernova. And that same something arranged for the gamma pulse and the particle storm ter run right smack bang into our solar system.”