The Genius Wars

ONE

Two dented lift doors were embedded in a wall of pebblecrete. Between them, the up button looked slightly traumatized, like a punching bag. It was hard to believe that the University of New South Wales had just installed a state-of-the-art, web-based management system to run its elevators.

Cadel was convinced that they had to be at least thirty years old.

Right, he said, eyeing an indicator panel. We’ll wait till they’re empty before we give it a go.

Ping! The words had barely left his mouth when one set of double doors slid open, revealing a lank-haired student in a Metallica T-shirt who blinked in sheer astonishment as he surveyed the line of people confronting him. Then he ducked his head, adjusted his backpack, and shuffled off toward the nearest lecture theater.

He must be in my course, Cadel decided, cursing himself for being so slow off the mark. Even after three weeks of seminars, he still didn’t recognize many of his fellow students.

Do you know who that was? he asked, in the faint hope that Hamish, at least, might be able to help. But Hamish simply shrugged. He regarded Introductory Programming as an insult to someone who could boast a genuine police record, and had roundly dismissed many of the other teenage hackers with whom he was forced to associate as a pathetic bunch of script-kiddies.

Cadel couldn’t help thinking that Hamish had an attitude problem. Though the two of them were in exactly the same boat, Cadel wasn’t perpetually bitching about its shape or its color. Like Hamish, he had been forced to attend university; the demanding nature of his computer engineering course work was supposed to keep him so busy that he wouldn’t be tempted to engage in any illegal hacking operations. Unlike Hamish, however, Cadel had been quite happy to enroll. He had always wanted to attend a proper university, with legitimate teachers. And if that meant relearning all his painfully acquired programming skills . . . well, he was prepared to make the sacrifice.

Hamish wasn’t. He had left high school a year before, at the age of sixteen, to pursue his own, very specialized interests. Only the combined urgings of his parents, his lawyer, his psychiatrist, and the juvenile justice system could have pushed him back into a highly structured academic environment. It’s not like there’s anything they can actually teach us in a place like this, he’d said to Cadel on one occasion. "We’re in a totally different league. We’ve been out in the real world. We’ve fought real b-battles, and you can’t do that without breaking a few rules. We’re cyberwarriors, not schoolboys."

It had been hard to keep a straight face, because Cadel couldn’t imagine a more unlikely pair of warriors. Hamish looked like an archetypal computer geek, with his glasses and his braces and his bleached, knobbly frame, while Cadel had no illusions about his own appearance—which was unthreatening, to say the least. Angelic blue eyes and a halo of chestnut curls had rescued Cadel from more sticky situations than he cared to admit. And despite the rapid approach of his sixteenth birthday, he was still unusually small for his age.

Mind you, he thought, glancing at the three people lined up next to him, none of us are exactly unobtrusive. It wasn’t surprising that the lank-haired fellow in the elevator had blinked at the sight of them. Though Hamish belonged to a physical type that was quite common in most computer engineering classes, he wore a wholly unconvincing tough-guy outfit: biker’s boots, ripped jeans, studded belt. Beside him, Cadel looked like a cherub from a church ceiling. Then there was Judith, massive and middle-aged, with long, frizzy gray hair, fluorescent pink glasses, a shoulder bag made of recycled tea towels, and layers of tie-dyed hemp flapping around her ankles. As for Sonja, she was the most conspicuous of them all. Her cerebral palsy meant that she was racked by continual, eye-catching muscular spasms. What’s more, her wheelchair was an imposing piece of technology that tended to dominate whatever space it occupied, thanks to the huge amount of equipment attached to it.

Not that any of this equipment was as big or as clumsy as her old Dyna Vox machine. Once upon a time, Sonja had been forced to spell out her remarks on a keyboard, which had then transmitted them as spoken language. For someone with unreliable motor skills, it had been a slow, laborious, tiring process.

Now, thanks to Judith Bashford, Sonja was hooked up to a revolutionary speech synthesizer. From one of her mysterious offshore bank accounts, Judith had extracted enough money to pay for the very latest kind of system. If Sonja’s going to be studying at university, Judith had declared, then she’ll need all the help she can get. This help included a cutting-edge neurological interface device that interpreted signals sent by Sonja’s brain to her vocal cords. A tiny wireless transmitter resting on her voice box then relayed the signals to a portable computer that decoded them, matching them against a set of prerecorded words in its databank. As a result, Sonja was not only able to utter her thoughts aloud—via the speech synthesizer—but also direct her wheelchair to stop, go, slow down, speed up, turn, retreat . . . whatever she wanted it to do.

At first, Cadel had assumed that this new system would give her complete independence. He had expected to see his best friend making her own way around town, or at least around the university. Most public buildings now contained ramps and lifts and automatic doors; as far as Cadel knew, it was illegal not to provide access for people in wheelchairs. He’d been convinced that Sonja would soon find the trip to her Advanced Mathematics class just as easy as the course itself.

He hadn’t reckoned, however, on the large amount of push-button technology standing in her way. Sonja couldn’t manage wall-mounted buttons. She would hurt herself trying vainly to hit them as she wrestled with her own wayward limbs. Pole-mounted buttons were almost as bad as the wall-mounted variety. So when it came to crossing roads or operating elevators, she was at a serious disadvantage. Without help, Sonja couldn’t be sure of reaching her classes on time.

To Cadel, this was unacceptable. He found it hard to believe that all the money, effort, and sophisticated research lavished upon Sonja’s new wheelchair could be undermined by something as basic as a little plastic button. It was ludicrous. It was unfair. Cadel knew how hard her life had been. He knew that, after being abandoned at an early age, she had been shunted from one group home to the next. Her only real friends (before her first meeting with Cadel) had been nurses and nurses’ aides. She had fought to speak, fought to move, fought to learn. Every day had been a battle. And despite the fact that she now had Judith to take care of her, Sonja’s life was still far from easy. She couldn’t even tie her own shoes or wash her own hair.

The last thing she needed was yet another obstacle blocking her path to freedom.

So Cadel had decided to tackle the problem himself. After doing a little research, he’d realized that every up and down button on campus could be circumvented, given the right tools. And it just so happened that he had the right tools. He had Sonja’s wireless transmitter, which could be reprogrammed. He had the university’s own wireless Internet connection, which could pick up her signals and pass them on to a special server. Most important, he had the new elevator management system (or EMS), which was connected to the World Wide Web.

Cadel had quickly worked out that, with elements like these in place, there was no need for Sonja to push any buttons. All she had to do was think of a command and it could be routed through to the EMS via her wireless transmitter. Of course, that meant hacking into several secure networks, but he had no qualms about doing so. Not for a good cause. And if the arrangement actually worked, it could be used to help other people with similar disabilities.

He told himself this, though he still felt bad. Having promised not to do any more unofficial hacking, he couldn’t help struggling with a faint sense of guilt as he stared up at the indicator panel. It wasn’t that he had straight-out lied. He had simply chosen not to keep everyone properly informed. Sonja knew what he was doing, naturally. So did Judith. Hamish was in on the secret because he and Cadel were classmates; it was inevitable that they would have bumped into each other, purely by accident, just before the first test run of Sonja’s modified transmitter. But nobody else was aware of Cadel’s latest project. Not even his foster parents, Saul and Fiona Greeniaus.

He was hoping that if he presented them with a completely successful, exhaustively tested, thoroughly worthwhile service to humanity, they would overlook the fact that he hadn’t been entirely honest with them. Surely they would understand? It wasn’t as if he had liked keeping them in the dark. It was just that Saul happened to be a police detective. And police detectives are notoriously unsympathetic when it comes to illicit network infiltration.

Once Cadel’s system was up and running, however, even Saul was bound to see how beneficial it was.

Right, Cadel said again. Then he turned to Sonja. Are you ready?

"I’m-ready, was her synthesized response, which had a slightly less robotic tone to it than anything produced by her old Dyna Vox. Shall-we-go-up?"

Remember, you have to be specific. Cadel felt that this point was worth repeating. Just to be on the safe side. Code, location, level, destination.

"I-know." Sonja sounded calm. She always did, because she talked through a machine. Only by studying her appearance was it possible to tell if she was agitated; for one thing, her muscular spasms became more violent when she was stressed.

But as her brown eyes strained toward him, Cadel could see that she was excited, rather than anxious. Her flushed cheeks gave her away.

"Audeo, EEB, level-G-up-level-two," she intoned, her synthesizer responding to directions that were also being channeled toward the EMS. Cadel immediately lifted his gaze. Above him, the indicator panels showed that elevator one was stuck on level three. But elevator two was still on the ground floor; its doors parted just as he glanced at them.

Sonja’s wheelchair began to move. She guided it carefully into the mirrored box, which shuddered beneath the weight of all her equipment. Judith followed her. Cadel was next in line, and made room for Hamish by pressing against one wall.

When the doors banged together again, they nearly squashed Hamish’s enormous, overloaded backpack.

"Going up," said a disembodied female voice.

Did someone press that? Hamish asked, gesturing at the button labeled 2. It was glowing softly, unlike the buttons surrounding it.

Nope, Judith replied. It was all lit up when I got in.

Then it’s worked! Hamish crowed. But Cadel raised a cautionary hand.

Just wait, he said. Let’s see. We can’t be sure, yet.

With a lurch, the elevator began its ponderous climb. Cadel checked his watch. While Sonja’s next class wasn’t for another half hour, he and Hamish were due at the Rex Vowels lecture theater in less than ten minutes. It would have been nice to run a whole series of different tests, at a variety of different locations. Unfortunately, however, that wouldn’t be possible. Not yet, anyway.

"Second floor,"the elevator announced, grinding to a halt. And Hamish punched the air in a victory salute.

Yes! he exclaimed.

Cadel wasn’t convinced, though. When the doors opened to reveal another startled-looking student, he realized that he had mistimed the whole procedure. I should have done this at night, he fretted. There are too many people around. Too many variables. I wasn’t thinking.

He said as much after he’d hustled everyone out of the lift.

We can’t get a clean set of results, he observed. Not right now. We’re up against the scheduling algorithms. That girl who just got in, she might have affected the outcome.

"I-don’t-think-so,said Sonja. The-button-lit-up, remember?"

It’s still inconclusive. Someone else might have pushed it by accident. Though Cadel could sympathize with her desperate optimism, he didn’t approve of unscientific methods. "We should do this at night. Or on a Sunday, when no one’s around. It’ll be the same with the traffic lights, when I tackle those. We’ll have to trial them really early, like at three o’clock in the morning."

Traffic lights? Hamish echoed. What about the traffic lights?

I’ll tell you later. Cadel had just spotted a woman marching toward them down a nearby corridor. He didn’t want anyone else listening in. He didn’t want the whole world to know that he was about to target the Sydney Coordinated Adaptive Traffic System. I’ve got to go, he informed Sonja. I’ll be late otherwise. Do you want to meet for lunch?

She can’t, said Judith. She has a physio appointment.

Oh. Cadel accepted this, but wouldn’t let Judith hijack the conversation. She was always doing it, nowadays, and it annoyed him. In his opinion, she was being overprotective; Sonja would be eighteen in less than a month, at which time she would become an adult, with an adult’s right to choose. In other words, she would be taking charge of her own destiny.

And if she decided to miss a few appointments, that would be her privilege—no matter what her new foster mother might think.

Well, what about this afternoon? Cadel continued, addressing Sonja. You could come over to my house, and we could talk about a weekend test run.

She’d be better off at home, was Judith’s opinion. It’s set up properly.

By this she meant that Cadel’s house didn’t have ramps, sensor lights, or automatic doors, whereas Judith’s seaside mansion was fitted out with all these features, and more besides. It was a fully wired Smart House—an intelligent environment.

Cadel’s house, in contrast, was as dumb as a doorknob. Or so Judith seemed to imply whenever she compared it unfavorably with her own.

"I’ll-come-over-to-your-place-if-I’m-not-too-tired, Sonja interjected. Physiotherapy-can-wipe-me-out-sometimes."

Sure. Cadel gave a nod. He was aware of how tired she could get doing the simplest things. What if I call you?

"Okay."

I’ll be working at home, so you can reach her there, said Judith, causing Hamish to frown. He was jealous of the work Judith did. As a condition of her parole, she had recently set up some kind of forensic accounting consultancy; Hamish envied the amount of time she spent helping the police to track down dirty money while he himself was stuck in school. I could help the police, he’d often said. Why don’t they ask me to help? Why does Judith get all the b-b-breaks? He didn’t seem to realize that he had been very, very lucky—that he could easily have ended up in a juvenile detention center, or a community service program. For some reason, he remained unconvinced that he had done anything wrong by joining the illegal operation known as Genius Squad. The fact that at least one of its former members was now in prison didn’t appear to faze him in the least. Nor did the attitude of his fellow squad members Cadel and Sonja, who wanted to put the past well and truly behind them.

As far as Hamish was concerned, trying to bring down a corrupt organization could only be a good thing, no matter what questionable means you might employ to do it.

Okay—well, I’ll call you, Cadel assured Sonja before Hamish could make one of his sour remarks about Judith’s busy schedule. Some time after lunch, say? Around two? And we can work out who should go where.

"All-right, Sonja agreed, her calm, metallic delivery undermined by her eager expression. See-you-later, then."

Bye. Cadel began to edge away. Bye, Judith.

Bye, boys. Have fun.

Hamish snorted. He didn’t respond to Judith’s cheerful wave. And on his way downstairs, he accused her of taking the piss.

Like we could possibly have any fun in Pediatric Programming, he complained. "Do you know what she told me last week? She told me she was chasing after money that Prosper English has tucked away in some tax haven somewhere. Can you b-believe that? The police are going after Prosper English, and they haven’t come to you for help!"

Because I don’t want to help. Cadel slammed through a fire door. I wouldn’t help even if they asked me.

"Yeah, but they d-didn’t ask you. That’s what I’m saying. It’s like they think you’re useless, when you probably know more about Prosper English than anyone. Hamish then launched into his usual rant about the criminal stupidity of disbanding Genius Squad: how it wouldn’t have cost too much to run, no matter what the accountants said; how its teenage members had not been the least bit unreliable, no matter what the police commissioner claimed; and how, if Genius Squad had been permitted to survive, Prosper English would have been caught within weeks of his escape from prison. Instead of which, we’re all given a slap on the wrist and told to go home! And nine months later Prosper’s still at large, free as a bird and breathing down our necks!"

He’s not breathing down our necks, Cadel said shortly. He’s gone to ground.

"Yeah, b-but he’s still out there, isn’t he? And you know him better than anyone. The police should be begging you to help."

No they shouldn’t, Hamish! Because it wouldn’t do any good! Cadel suddenly became aware of how loud his voice was as it echoed around the concrete walls of the stairwell. So he continued more quietly. I don’t want Prosper English in my life anymore. If I leave him alone, he’ll leave me alone. It’s a tradeoff.

You can’t be sure of that.

Yes I can. Cadel was sure of it. He had calculated the probabilities. There could be no other explanation for the nine months of perfect peace that he’d enjoyed—unless, of course, Prosper English was dead and buried. If he saw me as a threat, he would have got to me by now, Cadel went on. He could have killed me the minute I left the safe house. But he didn’t. So I’m going to be fine, as long as I keep my nose out of his business.

Do you think he’ll go after Judith, then? Hamish queried, following Cadel down another flight of stairs. "Since she’s sticking her nose into his b-business?"

I don’t know. It was a good question. It had certainly crossed Cadel’s mind. Saul Greeniaus, however, had assured him that Judith was just a very small part of a large long-term, ongoing pursuit of Prosper English, whose criminal empire was slowly being taken apart, piece by piece, all over the world.

According to Saul, police from half a dozen different countries had so far failed to uncover any evidence that Prosper was trying to undermine their investigations. There had been no attempts to bribe or kill or intimidate any members of the task force. And this meant that Judith would probably be safe as well.

Because they’re nowhere near Prosper, Cadel had decided upon hearing this news. If they were getting close to where he is, they’d find out soon enough. But he had said nothing. Not even to Saul.

He wasn’t going to make himself a target by offering up any unsolicited advice.

Anyway, I’m happy as I am, he said. I don’t want to get involved in stuff like that. I like things the way they are.

You must be joking. Hamish sounded genuinely shocked. Aren’t you b-bored to death?

No. Cadel pushed through another fire door, emerging into a wide, sloping hallway near the Rex Vowels lecture theater. I’m happy.

"How can you be? In this place? It’s so dull."

It’s not dull. It’s normal. It’s a normal life. It was, in fact, Cadel’s first taste of a normal life, and he’d been savoring every moment. Things were so easy. So free. He could go anywhere he wanted without having a surveillance team tagging along. He could say anything he wanted without wondering if the people who were listening to him had some kind of hidden agenda. He could stroll around campus secure in the knowledge that none of his fellow students was going to explode.

For fifteen years, he had lived under constant scrutiny. He’d grown accustomed to being closely monitored, first by Prosper English, then by the police—who had been afraid of what Prosper might do to him. As heir to a criminal empire, Cadel had been brought up in an atmosphere of invasive scrutiny, subtle manipulation, and unending lies. Even his education had been an exercise in duplicity. At the age of thirteen, he’d been enrolled in a college known as the Axis Institute, which had been established for the express purpose of turning him into the world’s greatest thief, liar, and con artist. What’s more, he had escaped that particular trap only to fall into another one—which, like the Institute, had been the work of Prosper English.

As far as Cadel was concerned, Genius Squad hadn’t been a fearless team of brilliant crusaders secretly working to bring down the world’s most evil corporation. It had been a naïve group of opinionated suckers who had become more and more entangled in one of Prosper’s cunning schemes. Cadel didn’t mourn the loss of Genius Squad. Not one little bit. He didn’t need Genius Squad to give his life meaning.

Now that he had a real home, and real parents, and real friends—now that he had enough room to move, and talk, and make his own decisions about his own future—why would he want anything else?

Hey, Cadel. Hamish wouldn’t let up. Can I ask you something?

I suppose so. Cadel wasn’t keen to continue their discussion. A crowd was gathering outside the lecture theater, drifting in from every point on the compass, and he didn’t want to be overheard. As long as it’s not about Prosper English.

"But what if he doesn’t know? Hamish demanded, blithely ignoring Cadel’s request. What if that’s why he hasn’t tried to kill you: b-because he still thinks you’re his son? What do you think will happen when he finds out you’re not?"

Oh, shut up, Hamish, Cadel said crossly. Then he darted forward, swerved past a press of rumpled students, and plunged through the open door beyond them.

TWO

Introductory Programming was divided into two classes: basic and advanced. Advanced students didn’t have to fight for a place in the Rex Vowels lecture theater, which was big enough to accommodate every one of them. Scattered thinly across three hundred or so brightly upholstered seats, the advanced class could afford to spread out a little.

At times, however, Cadel almost wished that he belonged to the larger group. There were so many basic students that they were never asked to move down to the front, please. Cadel would have felt less conspicuous in a crowd like that. He would have found it easier to keep a low profile. And he could have chosen a seat up at the back without attracting any kind of attention.

Not that he was intimidated, or scared of being caught out. He didn’t find the course work especially hard. But he preferred to keep a low profile because he wasn’t sure how much his teacher actually knew about him. Although the campus admissions office knew everything there was to know, Saul Greeniaus had insisted that certain aspects of his foster son’s background remain completely confidential. Cadel had even enrolled under Saul’s name—Greeniaus—despite the fact that the adoption process was taking a long, long time.

"You’re my son, now, Saul had declared. Mine and Fiona’s. You don’t have to worry about Chester Cramp anymore. Chester Cramp is irrelevant."

Chester Cramp was, in fact, Cadel’s biological father. But since Chester was sitting in an American jail, charged with all kinds of offenses (including conspiracy to commit murder), Cadel could only conclude that he was irrelevant—in the legal sense, at any rate. And since Cadel had never even met Chester Cramp, there wasn’t much of an emotional connection between them. In fact, of all the various fathers who had cluttered up Cadel’s life over the years, Chester was probably the least important.

Phineas Darkkon had been important; he had tried to mold Cadel into a criminal mastermind. Prosper English, Darkkon’s right-hand man, had also been very important; he had engineered the death of Cadel’s mother, before proceeding to mess with her infant son’s head. Saul Greeniaus had been the most important of the lot, kindly rescuing a lonely, mixed-up, homeless kid from a life full of social workers and group homes. All three men had viewed themselves as father figures and had behaved accordingly.

Only Chester Cramp had displayed a complete lack of interest in his own flesh and blood. Though a brilliant scientist, he was also (in Saul’s opinion) a totally deficient human being.

He’s done you a favor, Saul had once remarked. You can ignore Chester Cramp, because he’s ignored you. Unlike Prosper English. Prosper, unfortunately, had always treated Cadel as his personal possession—until a few months ago. Perhaps news of Cadel’s true paternity had filtered down to him at long last. Perhaps that was why Prosper had gone to ground.

Perhaps he wasn’t interested in Cadel now that he knew they weren’t blood relations.

Whatever the reason, he had suddenly withdrawn from Cadel’s life. So had Phineas Darkkon—who was long dead—and Chester Cramp, who had never been a big part of it to begin with. Therefore, for all intents and purposes, Cadel was now just a policeman’s son. An ordinary kid. And although he might have been a little younger than his classmates, with more memorable features, he was careful not to dress or behave in a manner that was going to get him singled out. If anything, he was one of the quieter students.

Nevertheless, he had a funny feeling that his teacher knew something about him—something more than just his name and student number. Richard Buckland was in charge of Introductory Programming; he had been given the tricky job of coaxing several hundred budding computer engineers through the first year of their degrees. Despite the size of his class, however, he always seemed to remember who Cadel was. And occasionally, when Cadel asked a question, Richard’s benign regard would become rather more intent than usual.

Had Richard been told the full story? Or was he simply impressed by the insightful nature of Cadel’s questions?

It was hard to decide.

What was all that stuff about traffic lights? Hamish queried as he sat down beside Cadel in one of the middle rows. "Why d-didn’t you mention it to me?"

Cadel sighed. Hamish saw himself as an expert on all things traffic-related because he had once hacked into the Digital Image Department of the Roads and Traffic Authority. His aim had been to tamper with various speed camera photographs.

It’s just an idea I had, Cadel muttered, glancing uneasily over his shoulder. But no one was listening. If Sonja’s wheelchair could get a signal through to the regional computer that runs all the controller boxes around here—

Then she wouldn’t have to press a ‘walk’ button, Hamish concluded. Yeah, I get it. Hack the loop detector input, somehow.

It depends what’s in there. Cadel cast his mind back to his former infiltration of the Sydney Coordinated Adaptive Traffic System. He’d been in elementary school at the time, and his approach had been a little heavy-handed. It’s a while since I poked around in SCATS, he confessed, almost sheepishly. I don’t really know what’s been happening. I don’t know if they’ve got any kind of new strobe preemption program for emergency vehicles. Or how many microwave detectors have been installed.

Oh, I can tell you that, said Hamish in a condescending tone. But all at once Richard Buckland appeared, laden with technology, and Hamish couldn’t risk uttering another word.

Even a whisper would have been audible in the sudden hush.

Richard dumped his laptop on the podium, where various plugs and cables allowed him to connect his computer to the theater’s audio-visual system. He was tall and bespectacled, with neatly trimmed brown hair and an open, genial, squared-off face; he wore a baggy old T-shirt over jeans and sneakers. For a minute or so he flicked switches and pushed buttons, peering back at the big white screen on the wall behind him. Then he addressed his audience, delivering information in explosively rapid, breathlessly excited bursts like machine-gun fire.

Words and ideas seemed to erupt out of Richard, as effervescent as a carbonated soft drink.

Today we’ll be looking at stack frames and buffer overflows, he observed, getting straight to the point. "I used to save this one for my third-year course, but buffer overflows arise from poor programming practice, and by the time you’re in third year, it’s too late to fix that up. With a fleeting smile, he added, The problem is that if your data is stored next to your program, and your users are allowed to put in as much information as they like, then the data can become part of your program."

None of this was news to Cadel. He’d launched quite a number of buffer overflow attacks in the past. But he was interested to hear Richard’s thoughts on programming solutions. As a matter of fact, he was interested in everything that Richard had to say about programming—because it completely contradicted what the Axis Institute had taught.

There, the emphasis had been on infiltration. Cadel’s Infiltration teacher, Dr. Ulysses Vee (a.k.a. The Virus), had delighted in loopholes, weaknesses, vulnerabilities. And Prosper English had been the same. You can only tell whether you’ve mastered a system if you isolate and identify its weakest point, he had once advised Cadel. If you knock that out and the whole system collapses, then you know you’ve got a handle on it. This opinion had been endorsed by Dr. Vee, who had created only to destroy. He’d created computer viruses and malware. He’d constructed labyrinthine security programs with built-in flaws, which had given him free access to many a company’s databanks. He’d been a consummate hacker, with a hacker’s mind-set.

In other words, he had been deficient in what Richard liked to call style.

Cadel was still coming to terms with this concept. It had something to do with simplicity, and something to do with practicality. It was a measure of how you approached a problem—of how well you understood the fundamentals of programming. But it was also an attitude: a kind of inherent appreciation of all things clean, clear, and beautiful. Cadel couldn’t help thinking that Sonja would have grasped what Richard was talking about. Her love of numbers was almost aesthetic; she would go into raptures over an exquisitely balanced algorithm. For Sonja, it wasn’t just getting there that mattered. It was the way you got there.

Apparently, Richard felt the same. He wouldn’t have liked Genius Squad’s scrambling, headlong, piecemeal approach to solving problems. And he would have deplored the Axis Institute’s choice of problems to solve. When you’re really young, he had pointed out during his very first lecture, "it’s all about puzzles, about unlocking secrets and cracking codes. But as you mature, you come to realize that none of this means anything unless it helps people and makes the world a better place." Trashing networks or sabotaging software clearly weren’t stylish goals, in Richard’s view.

Cadel sometimes wondered if he himself was making the world a better place by helping Sonja to push buttons. He certainly hoped so.

Psst. Suddenly Hamish jabbed him in the ribs. Look who’s here.

Cadel hadn’t been watching the door. He’d been staring at a stack-frame diagram projected onto the screen behind Richard—who abruptly broke off in the middle of his lecture. Can I help you? asked Richard. Are you lost?

He was addressing the new arrival: a neat, wiry, dark-haired man wearing a suit and tie that looked bizarrely out of place among so many hoodies and cargo pants. It was painfully obvious that this man didn’t belong in Richard’s class.

Cadel’s stomach did a backflip.

I’m here for Cadel, said the newcomer, so quietly that his Canadian accent was barely perceptible. Cadel stared at him, paralyzed.

Only something very, very urgent would have prompted Saul Greeniaus to interrupt an Introductory Programming class.

Oh . . . well. Okay. Richard seemed hesitant. He glanced at Cadel, who was slowly shutting his laptop. Are you all right with that, or . . . ? I take it you know each other?

Cadel nodded, flushing. He pushed his computer into its bag, uncomfortably aware that almost every single person in the auditorium was studying him with intense curiosity.

Only Hamish appeared to be more interested in Saul.

Do you want me as well? asked Hamish. But the detective shook his head.

No, he rejoined. You can stay. Then he turned to Richard. Sorry about this. If it wasn’t important . . .

Oh, look. With a wave of his hand, Richard signified complete understanding. These things happen.

Yes. They do. Unfortunately. Saul’s tone was grim. He watched Cadel sidle past eight pairs of denim-clad knees while Richard adjusted his glasses. The strained silence was broken only by the pad of Cadel’s rubber soles and a muffled cough from the back of the hall. Cadel tried not to look at anyone. On his way to the exit, he kept his head down and his pace rapid.

He was mortified.

As a schoolkid, he had always been a detached little weirdo, isolated from the rest of the herd. Since then he’d adopted a kind of camouflage, having learned how to dress and talk and conduct himself like other people. But at this precise moment, he felt as if he were twelve all over again.

Okay, said Richard, addressing his other students as Saul followed Cadel out of the room. So those integers, they take up how many bytes?

Then the door creaked shut, muffling Richard’s voice.

Wait. Saul grabbed at Cadel’s shoulder, lengthening his stride in an effort to catch up. I’m sorry. I tried to call, but you weren’t answering.

I always put my phone on mute before a lecture. Struck by an awful possibility, Cadel stopped in his tracks. Is it Fiona? he asked hoarsely. Is she—is she all right?

It was a measure of Saul’s preoccupation that for a moment he stood blank-eyed, as if he didn’t recognize his own wife’s name. Then he blinked, tightening his grip on Cadel.

What? Oh yeah. She’s fine. At the moment, she’s . . . Saul checked his watch. She’s on her way home from work.

Why? Cadel demanded, searching the pallid, fine-drawn face that hung over him. He knew that his foster mother wouldn’t have canceled her appointments for any minor reason. She was a social worker, with an overwhelming caseload and very little support. Only a real emergency