“You've got to be joking, Bruno—”
“Why? Any computing circuit can be built by stringing together enough NAND gates; you think we can't leverage packet switching into a NAND gate? But that's just the proof that it's possible; I expect we can actually make it a thousand times tighter.”
Campbell said, “I'm going to get some aspirin and come back.”
We roped in Alison to help, but it still took us six weeks to get a workable design, and another month to get it functioning. We ended up exploiting authentication and error-correction protocols built into the internet at several different layers; the heterogeneous approach not only helped us do all the calculations we needed, but made our gentle siphoning of computing power less likely to be detected and mistaken for anything malicious. In fact we were “stealing” far less from the routers and servers of the net than if we'd sat down for a hardcore 3D multiplayer gaming session, but security systems had their own ideas about what constituted fair use and what was suspicious. The most important thing was not the size of the burden we imposed, but the signature of our behavior.
Our new globe-spanning arithmetical telescope generated pictures far sharper than before, with kilometer-scale resolution out to a billion kilometers. This gave us crude relief-maps of the far-side planets, revealing mountains on four of them, and what might have been oceans on two of those four. If there were any artificial structures, they were either too small to see, or too subtle in their artificiality.
The relative motion of our sun and the star these planets orbited turned out to be about six kilometers per second. In the decade since Shanghai, the two solar systems had changed their relative location by about two billion kilometers. Wherever the computers were now that had fought with Luminous to control the border, they certainly hadn't been on any of these planets at the time. Perhaps there were two ships, with one following the Earth, and the other, heavier one saving fuel by merely following the sun.
Yuen had finally recovered his health, and the full cabal held an IM-conference to discuss these results.
“We should be showing these to geologists, xenobiologists ... everyone,” Yuen lamented. He wasn't making a serious proposal, but I shared his sense of frustration.
Alison said, “What I regret most is that we can't rub Sam's face in these pictures, just to show him that we're not as stupid as he thinks.”
“I imagine his own pictures are sharper,” Campbell replied.
“Which is as you'd expect,” Alison retorted, “given a head start of a few centuries. If they're so brilliant on the far side, why do they need us to tell them what you did to jump the border?”
“They might have guessed precisely what I did,” he countered, “but they could still be seeking confirmation. Perhaps what they really want is to rule out the possibility that we've discovered something different, something they've never even thought of.”
I gazed at the false colors of one contoured sphere, imagining gray-blue oceans, snow-topped mountains with alien forests, strange cities, wondrous machines. Even if that was pure fantasy and this temporary neighbor was barren, there had to be a living homeworld from which the ships that pursued us had been launched.
After Shanghai, Sam and his colleagues had chosen to keep us in the dark for ten years, but it had been our own decision to cement the mistrust by holding on to the secret of our accidental weapon. If they'd already guessed its nature, then they might already have found a defense against it, in which case our silence bought us no advantage at all to compensate for the suspicion it engendered.
If that assumption was wrong, though? Then handing over the details of Campbell's work could be just what the far-side hawks were waiting for, before raising their shields and crushing us.
I said, “We need to make some plans. I want to stay hopeful, I want to keep looking for the best way forward, but we need to be prepared for the worst.”
* * * *
Transforming that suggestion into something concrete required far more work than I'd imagined; it was three months before the pieces started coming together. When I finally shifted my gaze back to the everyday world, I decided that I'd earned a break. Kate had a free weekend approaching; I suggested a day in the Blue Mountains.
Her initial response was sarcastic, but when I persisted she softened a little, and finally agreed.
On the drive out of the city, the chill that had developed between us slowly began to thaw. We played JJJ on the car radio—laughing with disbelief as we realized that today's cutting-edge music consisted mostly of cover versions and re-samplings of songs that had been hits when we were in our twenties—and resurrected old running jokes from the time when we'd first met.
As we wound our way into the mountains, though, it proved impossible simply to turn back the clock. Kate said, “Whoever you've been working for these last few months, can you put them on your blacklist?”
I laughed. “That will scare them.” I switched to my best Brando voice. “You're on Bruno Costanzo's blacklist. You'll never run distributed software efficiently in this town again.”
She said, “I'm serious. I don't know what's so stressful about the work, or the people, but it's really screwing you up.”
I could have made her a promise, but it would have been hard enough to sound sincere as I spoke the words, let alone live up to them. I said, “Beggars can't be choosers.”
She shook her head, her mouth tensed in frustration. “If you really want a heart attack, fine. But don't pretend that it's all about money. We're never that broke, and we're never that rich. Unless it's all going into your account in Zürich.”
It took me a few seconds to convince myself that this was nothing more than a throwaway reference to Swiss banks. Kate knew about Alison, knew that we'd once been close, knew that we still kept in touch. She had plenty of male friends from her own past, and they all lived in Sydney; for more than five years, Alison and I hadn't even set foot on the same continent.
We parked the car, then walked along a scenic trail for an hour, mostly in silence. We found a spot by a stream, with tiered rocks smoothed by some ancient river, and ate the lunch I'd packed.
Looking out into the blue haze of the densely wooded valley below, I couldn't keep the image of the crowded skies of the far side from my mind. A dazzling richness surrounded us: alien worlds, alien life, alien culture. There had to be a way to end our mutual suspicion, and work toward a genuine exchange of knowledge.
As we started back toward the car, I turned to Kate. “I know I've neglected you,” I said. “I've been through a rough patch, but everything's going to change. I'm going to make things right.”
I was prepared for a withering rebuff, but for a long time she was silent. Then she nodded slightly and said, “Okay.”
As she reached across and took my hand, my wrist began vibrating. I'd buckled to the pressure and bought a watch that shackled me to the net twenty-four hours a day.
I freed my hand from Kate's and lifted the watch to my face. The bandwidth reaching me out in the sticks wasn't enough for video, but a stored snapshot of Alison appeared on the screen.
“This is for emergencies only,” I snarled.
“Check out a news feed,” she replied. The acoustics were focused on my ears; Kate would get nothing but the bad-hearing-aid-at-a-party impression that made so many people want to punch their fellow commuters on trains.
“Why don't you just summarize whatever it is I'm meant to have noticed?”
Financial computing systems were going haywire, to an extent that was already being described as terrorism. Most trading was closed for the weekend, but some experts were predicting the crash of the century, come Monday.
I wondered if the cabal itself was to blame; if we'd inadvertently corrupted the whole internet by coupling its behavior to the defect. That was nonsense, though. Half the transactions being garbled were taking place on secure, interbank networks that shared no hardware with our global computer. This was coming from the far sid
e.
“Have you contacted Sam?” I asked her.
“I can't raise him.”
“Where are you going?” Kate shouted angrily. I'd unconsciously broken into a jog; I wanted to get back to the car, back to the city, back to my office.
I stopped and turned to her. “Run with me? Please? This is important.”
“You're joking! I've spent half a day hiking, I'm not running anywhere!”
I hesitated, fantasizing for a moment that I could sit beneath a gum tree and orchestrate everything with my Dick Tracy watch before its battery went flat.
I said, “You'd better call a taxi when you get to the road.”
“You're taking the car?” Kate stared at me, incredulous. “You piece of shit!”
“I'm sorry.” I tossed my backpack on the ground and started sprinting.
“We need to deploy,” I told Alison.
“I know,” she said. “We've already started.”
It was the right decision, but hearing it still loosened my bowels far more than the realization that the far side were attacking us. Whatever their motives, at least they were unlikely to do more harm than they intended. I was much less confident about our own abilities.
“Keep trying to reach Sam,” I insisted. “This is a thousand times more useful if they know about it.”
Alison said, “I guess this isn't the time for Dr. Strangelove jokes.”
Over the last three months, we'd worked out a way to augment our internet “telescope” software to launch a barrage of Campbell-style attacks on far-side propositions if it saw our own mathematics being encroached upon. The software couldn't protect the whole border, but there were millions of individual trigger points, forming a randomly shifting minefield. The plan had been to buy ourselves some security, without ever reaching the point of actual retaliation. We'd been waiting to complete a final round of tests before unleashing this version live on the net, but it would only take a matter of minutes to get it up and running.
“Anything being hit besides financials?” I asked.
“Not that I'm picking up.”
If the far side was deliberately targeting the markets, that was infinitely preferable to the alternative: that financial systems had simply been the most fragile objects in the path of a much broader assault. Most modern engineering and aeronautical systems were more interested in resorting to fall-backs than agonizing over their failures. A bank's computer might declare itself irretrievably compromised and shut down completely, the instant certain totals failed to reconcile; those in a chemical plant or an airliner would be designed to fail more gracefully, trying simpler alternatives and bringing all available humans into the loop.
I said, “Yuen and Tim—?”
“Both on board,” Alison confirmed. “Monitoring the deployment, ready to tweak the software if necessary.”
“Good. You really won't need me at all, then, will you?”
Alison's reply dissolved into digital noise, and the connection cut out. I refused to read anything sinister into that; given my location, I was lucky to have any coverage at all. I ran faster, trying not to think about the time in Shanghai when Sam had taken a mathematical scalpel to all of our brains. Luminous had been screaming out our position like a beacon; we would not be so easy to locate this time. Still, with a cruder approach, the hawks could take a hatchet to everyone's head. Would they go that far? Only if this was meant as much more than a threat, much more than intimidation to make us hand over Campbell's algorithm. Only if this was the end game: no warning, no negotiations, just Sparseland wiped off the map forever.
Fifteen minutes after Alison's call, I reached the car. Apart from the entertainment console it didn't contain a single microchip; I remembered the salesman laughing when I'd queried that twice. “What are you afraid of? Y3K?” The engine started immediately.
I had an ancient secondhand laptop in the trunk; I put it beside me on the passenger seat and started booting it up while I drove out on to the access road, heading for the highway. Alison and I had worked for a fortnight on a stripped-down operating system, as simple and robust as possible, to run on these old computers; if the far side kept reaching down from the arithmetic stratosphere, these would be like concrete bunkers compared to the glass skyscrapers of more modern machines. The four of us would also be running different versions of the OS, on CPUs with different instruction sets; our bunkers were scattered mathematically as well as geographically.
As I drove on to the highway, my watch stuttered back to life. Alison said, “Bruno? Can you hear me?”
“Go ahead.”
“Three passenger jets have crashed,” she said. “Poland, Indonesia, South Africa.”
I was dazed. Ten years before, when I'd tried to bulldoze his whole mathematical world into the sea, Sam had spared my life. Now the far side was slaughtering innocents.
“Is our minefield up?”
“It's been up for ten minutes, but nothing's tripped it yet.”
“You think they're steering through it?”
Alison hesitated. “I don't see how. There's no way to predict a safe path.” We were using a quantum noise server to randomize the propositions we tested.
I said, “We should trigger it manually. One counter-strike to start with, to give them something to think about.” I was still hoping that the downed jets were unintended, but we had no choice but to retaliate.
“Yeah.” Alison's image was live now; I saw her reach down for her mouse. She said, “It's not responding. The net's too degraded.” All the fancy algorithms that the routers used, and that we'd leveraged so successfully for our imaging software, were turning them into paperweights. The internet was robust against high levels of transmission noise and the loss of thousands of connections, but not against the decay of arithmetic itself.
My watch went dead. I looked to the laptop; it was still working. I reached over and hit a single hotkey, launching a program that would try to reach Alison and the others the same way we'd talked to Sam: by modulating part of the border. In theory, the hawks might have moved the whole border—in which case we were screwed—but the border was vast, and it made more sense for them to target their computing resources on the specific needs of the assault itself.
A small icon appeared on the laptop's screen, a single letter A in reversed monochrome. I said, “Is this working?”
“Yes,” Alison replied. The icon blinked out, then came back again. We were doing a Hedy Lamarr, hopping rapidly over a predetermined sequence of border points to minimize the chance of detection. Some of those points would be missing, but it looked as if enough of them remained intact.
The A was joined by a Y and a T. The whole cabal was online now, whatever that was worth. What we needed was S, but S was not answering.
Campbell said grimly, “I heard about the planes. I've started an attack.” The tactic we had agreed upon was to take turns running different variants of Campbell's border-jumping algorithm from our scattered machines.
I said, “The miracle is that they're not hitting us the same way we're hitting them. They're just pushing down part of the border with the old voting method, step by step. If we'd given them what they'd asked for, we'd all be dead by now.”
“Maybe not,” Yuen replied. “I'm only halfway through a proof, but I'm 90 percent sure that Tim's method is asymmetrical. It only works in one direction. Even if we'd told them about it, they couldn't have turned it against us.”
I opened my mouth to argue, but if Yuen was right that made perfect sense. The far side had probably been working on the same branch of mathematics for centuries; if there had been an equivalent weapon that could be used from their vantage point, they would have discovered it long ago.
My machine had synchronized with Campbell's, and it took over the assault automatically. We had no real idea what we were hitting, except that the propositions were further from the border, describing far simpler arithmetic on the dark integers than anything of ours that the far side had yet
touched. Were we crippling machines? Taking lives? I was torn between a triumphant vision of retribution, and a sense of shame that we'd allowed it to come to this.
Every hundred meters or so, I passed another car sitting motionless by the side of the highway. I was far from the only person still driving, but I had a feeling Kate wouldn't have much luck getting a taxi. She had water in her backpack, and there was a small shelter at the spot where we'd parked. There was little to be gained by reaching my office now; the laptop could do everything that mattered, and I could run it from the car battery if necessary. If I turned around and went back for Kate, though, I'd have so much explaining to do that there'd be no time for anything else.
I switched on the car radio, but either its digital signal processor was too sophisticated for its own good, or all the local stations were out.
“Anyone still getting news?” I asked.
“I still have radio,” Campbell replied. “No TV, no internet. Landlines and mobiles here are dead.” It was the same for Alison and Yuen. There'd been no more reports of disasters on the radio, but the stations were probably as isolated now as their listeners. Ham operators would still be calling each other, but journalists and newsrooms would not be in the loop. I didn't want to think about the contingency plans that might have been in place, given ten years’ preparation and an informed population.
By the time I reached Penrith there were so many abandoned cars that the remaining traffic was almost gridlocked. I decided not to even try to reach home. I didn't know if Sam had literally scanned my brain in Shanghai and used that to target what he'd done to me then, and whether or not he could use the same neuroanatomical information against me now, wherever I was, but staying away from my usual haunts seemed like one more small advantage to cling to.
I found a gas station, and it was giving priority to customers with functioning cars over hoarders who'd appeared on foot with empty cans. Their EFTPOS wasn't working, but I had enough cash for the gas and some chocolate bars.
The Year's Best Science Fiction (2008 Edition) Page 5