Zimmerman's Algorithm

2.06 Thur. Mar. 19

C OLONEL Gregory Mecham stood at a podium in a small, secure meeting room at Fort Meade. The room was designed to hold about two hundred people; at the moment it held ten. In a meeting about Zimmerman, ten was a quorum. It consisted of the National Security Council and a few select people from the various intelligence agencies.

In particular, Mecham noticed a new face from the DISA who sat next to General Adrian Harris, Chairman of the JCS.

"This is what we have," Mecham said, switching on a remote that operated the screen behind him. Surveillance photographs crossed the screen. "We've received these pictures from the team observing Gideon Malcolm. The team on Malcolm was carefully chosen and isolated, our communication has been through uncompromised channels." Mecham manipulated a mouse pointer across the screen behind him, highlighting the pictures in turn. "While the hope was that Malcolm might uncover new intelligence by his investigation, he has—up until yesterday—been researching already well-covered ground.

He's visited Dr. Zimmerman's home and members of her family. . ."

Mecham clicked a button, and the pictures changed to street scenes in Greenwich Village. "The second hope, that allowing Malcolm to roam unhindered would draw out other forces interested in Dr. Zimmerman, has borne fruit." Mecham clicked the mouse on one picture of a man dressed in a jogging suit. The picture blew up and filled the whole screen with a grainy, but recognizable photo of one of the gunmen who had attacked Malcolm and Zimmerman's sister. "This man is named Lyaksandro Volynskji, born Ukrainian, but he's been a resident of various Islamic states, mostly parts of the old Soviet Union. He is a recognized assassin, he's worked in Bosnia, Palestine, and inside Russia. He's associated with the International Unification Front, a loose confederation of extra-national paramilitary groups that operate out of the Middle East. After some backtracking, we've pinpointed his entry into this country as December 3, last year. He came into Miami on a Cuban passport."

Mecham slid the mouse around and clicked on another photograph. This time another man's picture expanded to fill the screen. "Hashim Abu Bakr, Syrian. We suspect that he's been involved in organizing various terrorist training camps in Syria and Libya, part of the same IUF. He entered the country on a Palestinian passport on December 2, last year."

Mecham clicked the last picture and a young man with dark hair and intense black eyes filled the screen. "The third man hasn't been identified yet. However, it seems clear the IUF is responsible for killing at least three people involved with Zimmerman. Consulting with the CIA, we've positively identified Volynskji as the shooter in the assassination of Morris Kendal."

Mecham shut off the display and leaned forward on the podium. "I'll hand the floor over to the CIA's expert."

One of the ten people stood up and walked over to the podium. He was a short black man named Williams who was one of the CIA's resident experts on Middle East terrorist organizations. "Gentlemen, we

are dealing with a very dangerous situation here. While, over the past decade, the IUF has been shifting its focus to economic and technological espionage, they are still terrorists. While I understand the grave threat Dr. Zimmerman poses to our SIGINT capabilities, I think the presence of the IUF suggests a threat that's much graver than the exposure of our cryptographic resources."

What little noise there was in the room silenced. Mecham looked up at Williams. He knew what Williams meant. Ever since Zimmerman's disappearance, the fear had been that her mathematical work for the NSA might be exposed. For a few years before Dr. Zimmerman came to work for them, the NSA's mission had been hampered, especially with digital communication, by the presence of strong cryptographic methods. After Zimmerman came, there was no such thing as strong encryption.

But that wasn't the only thing that Zimmerman was working on.

"If crypto was all the IUF was interested in, Zimmerman would never had had to disappear. Zimmerman's work could be passed on a single CD. They didn't need her work, they needed her. And from all appearances, Zimmerman went willingly. They've since been trying to get access to a Daedalus supercomputer. That doesn't make any sense unless they were interested in Zimmerman's work in information warfare. The fact that they're still operating in the country means they haven't smuggled Zimmerman out. That implies that they have a definite plan, and they need a Daedalus to carry it out.

We've had a number of alerts recently, where it appeared that there were hostile forces attacking domestic information systems. The virus that instigated the Wall Street crash has only been the most public. Since Zimmerman's disappearance, we've had computer-related power failures at seven major facilities, lost two major air traffic control systems for over three hours, and—for five minutes—lost the entire long distance phone network between the Rockies and the Mississippi. These may all be related, and may only be tests." Williams paused for emphasis, then said, "If they get access to a Daedalus, I would consider it as much a threat to the United States as if they had access to a weapon of mass destruction in every major city in the country."

Colonel Mecham was back in his office before eight in the morning, and around eight-fifteen, Emmit D'Arcy was knocking on his door.

"Come in, sir," Mecham said, standing up to meet D'Arcy.

D'Arcy shut the door behind him and took off his glasses to rub the bridge of his nose. "I wanted to talk to you, Greg. I wanted your take on Williams' analysis."

"I respect his expertise."

"That's an evasion."

"I know," Mecham waved to a chair in front of his desk. "Why don't you have a seat. You look tired."

"Four hours' sleep in the last three days, half unintentional." D'Arcy moved over to the chair and sighed. "You know he's right on the money about the IUF. They're probably the worst people that could have Zimmerman."

Mecham sat down himself. "Yes, I know. I don't dispute that."

"You have a reservation about something."

Mecham nodded. "I have reservations about Zimmerman. She wasn't taken. She left with an almost obsessive amount of premeditation and planning—"

"As Williams said, if the IUF has her, she went willingly."

"But why? Have you read her psychological profile?"

"Five times."

"Then you know what's bothering me. She's not an ideologue, barely a political bone in her body. Her personal life is practically antiseptic. No debts, and she cares little for money. Her strongest beliefs are about mathematics. How can someone like that be recruited by the IUF, of all people? She had the best hardware, the most sophisticated forum possible for doing her work, which is all she really cares about. You couldn't bribe her away from that. She doesn't have anything you can blackmail her with—even her family, she hasn't communicated with any of them in a couple of years."

"I've read the same things you have. Assuming the profile isn't wrong—and someone with her intelligence would be able to intentionally skew our profile, and hide her true feelings— assuming it isn't wrong, what conclusions are you drawing?"

"Zimmerman would only have left—and I don't care who might have facilitated it, because I doubt she would've—if it meant she could do work that, for one reason or another, she couldn ’t do here. She would never have left here just so she could reconstruct old information warfare viruses she's already designed for us. Doing old work would be pointless to her."

"What kind of work would she be doing?" D'Arcy asked. He leaned forward, his expression suddenly showing an intense interest in what Mecham was saying.

"Something that requires a Daedalus. Other than that, I don't know, and that's frightening." Mecham shook his head. "I suspect it has something to do with her work at MIT, since people from the Evolutionary Theorems Lab are working with her—but what it could be, I don't know. I'm not a mathematician, and, until now, I had thought that everything she did here was a logical extension of her work there."

D'Arcy nodded and leaned back. "True, perhaps, but nothing you've said means we change how we deal with this. Zimmerman is still a threat, probably more so than we ever thought. We still have to keep a tight watch on every Daedalus out there. Eventually the IUF will move on one of them, and then we have her."

"I just wish we hadn't lost Malcolm . . ."

Gideon and Ruth spent a good part of the evening on the subway. They went as far as Queens and back again, switching trains a number of times in an effort to foil any pursuit. Ruth was exhausted and spent most of the time asleep, leaning against Gideon's shoulder. Gideon was too keyed up to sleep. He spent most of the time staring at other passengers, wondering which ones were planning to attack them.

The rest of the time he thought about what was happening. Why was he here, next to Dr.

Zimmerman's sister, on the New York subway system?

"Julia, who are you?" he asked a mental image of the Doctor. "What are you doing?"

His only response was an enigmatic stare from those depthless gray eyes. What made her turn away? From her parents, from her sister, from her colleagues . . . ?

Christ, tell me why I turned away?

He must have been too tired, because that kind of question bore on things that he never wanted to think about.

Ruth must have felt him tense up because she sat up next to him and looked at him. "Are you all right?"

"I'm fine." The words were a whisper through clenched teeth.

"You're crying."

Gideon shook his head, but he raised his hand to his cheek and found wetness there. "It's just the smoke."

"It's all right," Ruth whispered. "You've been through a lot."

"It's not all right. It's never been all right." Gideon rubbed his forehead as if he could push the thoughts away, distract himself with what was going on around them now. "I'm a fraud," he whispered.

Ruth rubbed his shoulder.

"I couldn't hack it as a Fed," Gideon said. "I shouldn't be a cop either. I'll deserve it when IA pulls my badge."

"You aren't responsible—"

"My brother, my ex-partner . . . I got them both killed. Just because I wanted, someday, to be Rafe."

Ruth was silent for a long time before she said, "Rafe was your brother?"

Gideon nodded.

"I know what it is like to live in someone's shadow."

They were on the return trip from Jackson Heights, and morning light was streaming into the car as they rode over northern Queens. Ruth looked around as if she was looking for some reason to change the subject. "Where are we?" she finally asked.

"Queens," Gideon said, relieved to be talking about something else. "Going back to Manhattan."

She looked at the rest of the car. It was packed with people making the morning commute. Standing room only. She shook her head and whispered, "Is that safe?"

"I think we're all right now. The Israelis did us the favor of separating me from all the tracking devices—" Gideon felt the Micro-Uzi in his pocket. He'd had to strip off the silencer to allow it to fit.

"We should go to the FBI," Ruth whispered.

That was the easy answer, wasn't it? Gideon had been thinking the exact same thing for most of the night. There was one problem with it, though. "I can't."

"What do you mean, you can’t?"

"I can take you to them," Gideon said. "I can't stop."

Ruth's voice lowered even further. "Don't you realize that people are shooting at you?"

Gideon rubbed his healing leg and said, "I know." Not just at me. His voice was slow, halting, as he tried to explain why he needed to continue. Why he couldn't ask anyone for help. "I still have to find out

what's happening. Why." He closed his eyes and wondered how much of what he was saying was rationalization. "I can't back off now. I go to the Feds now, and the best that will happen is they'll hand me over to IA while they try and bury all their embarrassing mistakes." And I have to prove to myself that I can do this. Every time I've hit a snag, I've turned to someone to bail me out. Dad, Rafe, Kendal—

Ruth leaned back and sighed. Even with the motorcycle jacket, perhaps because of it, she looked very small and vulnerable. "You think I don't want to find Julie? She's my sister."

Gideon nodded. The train shot into a tunnel under the East River, briefly exchanging day for night. Gideon's hand drifted back toward the pocket with the gun. I'm doing this for Rafe. What he did for me has got to mean something.

Later on, as they rode under Manhattan, Gideon asked, "Do you think Julia could be working with the IUF?"

"Are you kidding? Why would she do that? It'd be pointless."

"She planned her disappearance," Gideon said. "Just like MIT. She even wiped her own home computer. Wherever she went, she planned to go there."

Ruth laughed. The sound was half derisive and half nervous. "You can't be suggesting that after all these years that Julie suddenly became political—not to mention political for these guys."

The train slowed for a stop, and the packed cars began to gradually empty out.

"What could they offer her?"

"To get her to jump ship at the NSA?" She shook her head. "You don't understand. All she really cares about is her work, it's almost a divine mission for her. From what I heard, the NSA gave her the best environment to conduct her work that she could possibly have."

Gideon thought back to their conversation in the restaurant. "Something she'd need a Daedalus for," he muttered.

"What?"

"What if they were watching us, had a man near us? What if something we did or said triggered the attack? What if we stumbled on something the IUF didn't want anyone to know?"

"Like what? We just talked about Julie's life, nothing secret—" Ruth shivered a little bit. "We didn't talk about anything worth shooting at us for."

Gideon stared out at a platform as the train pulled out. The lighted platform slid away and replaced itself with the depthless black of the tunnels. The clearest image was his own reflection in the window.

"She was working on something on her own. Something private. Everyone looking for Julia Zimmerman is afraid of what she was known to be working on for the NSA. What if the IUF offered her the opportunity to work on something she couldn't work on at the NSA?"

Ruth shook her head. "I know where you're going with that. I know it looks a lot like when she left MIT. But Julie isn't stupid. She'd consider the consequences of her actions. She knew that she could screw MIT, because she knew who would be backing her if things came to a head. She knew that she'd beat them." She turned her head and looked at Gideon. "This isn't the same. I can't see her making that decision. This is a no-win situation."

The train pulled to a stop again, and Gideon stood up. "Come on."

"What? Where are we going?"

"I want to make a stop at the library."

When Gideon sat behind one of the public terminals at the New York Public Library, Ruth asked him, "And what exactly do you expect to find here?"

Gideon cued up a search engine and said, "I want to look into what your sister might have been working

on."

"How the hell do you intend to do that?" Ruth pulled up a chair and sat next to him. "Are you some sort of police mathematician?"

"No," Gideon shook his head. "But I think the answer is somewhere in what we already know."

There was a pile of scratch paper and a small pencil box next to the computer. He took a sheet and a pencil and started scribbling a list of words;

"Information Warfare. Virus. Cryptography. Riemann. Number Theory. Aleph-Null. Evolutionary Algorithm. Zeta Function."

Gideon looked at the list of words. "That should be enough of a start."

Ruth watched as he scanned papers, articles, as well as the other detritus accumulated on the Internet. Those sites that weren't mathematical tended to be about private-sector information security. After about fifteen minutes, Gideon found a page that made him realize one of the fundamental reasons why the government was scared of losing Zimmerman. On the screen was a layman's description of public key cryptography, the de facto standard for secure personal communications on the Internet.

"No wonder they're frightened of her," Gideon whispered.

"What?" Ruth said.

"Look at this." Gideon tapped his finger on a paragraph that he had just scrolled onto the screen. "This whole process is based on very large prime numbers. . ."

"Okay, so?"

"That was at the heart of what she was doing at MIT, wasn't it?"

Ruth shrugged. "I never followed it very well. She was way past me by the time she left grade school."

Gideon scrolled through the article. "Most of the security on the Internet is based on these huge numbers, and on the fact that it's supposedly a practical impossibility to factor a four-thousand-bit number by brute force."

"So?"

"I'm not a mathematician, but one of the things that your sister's colleague, Dr. Nolan, told me—'Zimmerman was pushing the lab toward new theorems that could generate the primes, or factor huge numbers.'" Gideon shook his head. "No wonder the NSA wanted her, and wants her back. With that kind of algorithm there'd be no such thing as a secure communication on the Internet—or elsewhere for that matter. E-mail, credit-card transactions, private databases—you could crack any of it, all of it."

Ruth stared at the screen. "Do you think she managed that?"

"Why not?" Gideon said. "What would be worth more to an intelligence gathering agency? A factoring algorithm that renders the bulk of encrypted information in existence completely transparent." Gideon nodded to himself, leaning back. "And they have to be very careful bringing her back. If it became public knowledge that such an algorithm existed, it would become useless." Gideon tapped his fingers on the table. "That explains the government. . ."

Gideon was quiet a long while before Ruth interrupted him. "You don't sound completely sure."

Gideon shook his head. "I can make it fit with everything . . . except your sister. It fits with what the old man said about her designing parts of the NSA's computer security—" He sighed. "There's more to this. I know there's more to this. This doesn't explain why your sister disappeared. It certainly doesn't explain why she, or the IUF, would need a supercomputer."

"It doesn't? This sounds kind of heavy to me."

Gideon nodded. "But the work she was doing at MIT was using equipment anyone has access to, not particularly sophisticated. 200Mhz PCs. I could get more powerful computers used. So, if what she did was a direct outgrowth of the ET Lab, why would she suddenly need the kind of power a Daedalus provides? Not to mention, this is exactly the kind of thing the NSA was using her for. I'm sure that whatever she's doing now would have to be something that she couldn’t do at the NSA—"

"I keep telling you. She's not stupid. She wouldn't jump ship at the NSA unless she thought the odds were in favor of her getting away with it.

Gideon nodded. He'd been thinking along those lines himself. There was another possibility that Ruth wasn't seeing. What if Zimmerman didn't care about the odds? What if she was working on something that she thought was important enough to risk being hunted down by the Feds as a traitor?

There wasn't any question in Gideon's mind that Zimmerman had her own agenda. What if there was something she was working on in secret, ever since MIT? Maybe since before . . .

But what?

What could she think is that important?

Gideon stared at the screen, trying to think. Ruth looked at him and said, "Don't you think it's time to consider the FBI?"

Gideon looked at Ruth. "I doubt the government's priorities match ours— I don't think they care about bringing your sister in alive."

"And you do?"

The question made Gideon uncomfortable. He had been driven to this point by a need to discover what had happened in the warehouse, why Rafe had died. Somehow, his focus had changed. Julia Zimmerman had become his focus. He could rationalize it by saying that she had been the focus of what had happened at the warehouse. Was that the real reason? He was following this woman, finding himself fascinated by her history. . .

In his gut he knew that, if he discovered what she was doing, he could damage those who had shot him and killed Rafe. He knew he wanted to bring whatever happened to the press and to that Congressional hearing. He wanted to damage those who had damaged so much around him.

He wanted to vindicate himself.

But that wasn't it. Not completely.

He realized that he didn't want Julia Zimmerman to end like Rafe, or Kendal, or Davy Jones, or Kareem Rashad Williams. Whatever she had done, Gideon had an irrational belief that it wasn't treasonous. Somehow she was serving her first and only love. There was something in her that wasn't of Gideon's world. Gideon's world was constructed from self-serving politics, where his brother's death was some sort of bargaining chip, a political asset—or liability—depending on what side of the fence you were on.

Julia came from somewhere else. And, somehow, understanding her, what she was doing, would give Rafe's death the meaning that Gideon desperately needed. Gideon couldn't accept that all it had been was some interdepartmental screwup. . .

There was something larger, and much more important at stake.

Gideon looked at Ruth. Did he care about bringing Julia in alive? "I do," Gideon said quietly. "Believe me, I do."

Ruth looked at him a little oddly. "You don't have a crush on her, do you?"

Gideon laughed. "That's silly. I've never even met the woman."

He turned back to the computer screen and started calling up searches on the other terms that related to Dr. Zimmerman's work. As he worked, the phrase kept running through his head, I've never even met the woman.

He searched for things relating to "Evolutionary Algorithm," "Virus," and, "Information Warfare."

The search presented him with dozens of pages on the Evolutionary Algorithm. A few pages were actually archived copies of papers from the ET Lab at MIT. There were so many documents that Gideon threw Zimmerman's name into the search to pare down the list.

When he did that, he found all the MIT papers, and a document titled, "Tenth International Conference on Artificial Life."

Gideon stared at the title for a long time before he opened the document. He was remembering something Dr. Michael Nolan had said. "She began to act as if the programs we were creating were living creatures. . ." He also remembered the lone thing that she'd left on her own personal computer, a little icon labeled "life."

The document had an introduction to the term "artificial life." Gideon scanned the page, picking out phrases that caught his eye, or seemed important.

"Artificial Life labels human attempts to construct models—digital, biological, and robotic—that reproduce some of the essential properties of life. The goal of such models is to reveal the organizational principles of living systems on Earth, and possibly elsewhere . . ."

". . . requires a truly interdisciplinary approach that knits together fields of knowledge as diverse as mathematics and biology, computer science and physics, engineering and philosophy . . ."

". . . an important part of this effort is a search for independent principles of living systems, which apply to any living system, regardless of biology—or lack thereof. Artificial Life also considers the possibilities of life, artificial alternatives to a carbon-based chemistry."

"This sounds like so much science fiction," Ruth said.

Gideon nodded. "But, according to Dr. Nolan, this kind of research has been going on for decades. He said some of the first Genetic Algorithms were produced on an Apple II computer."

Gideon checked the conference schedule and found Dr. Zimmerman's name.

"Sat. June 29: 8:30-9:15 Keynote Talk, Julia Zimmerman, The Biology of the Internet."

Gideon stared at the title of her talk for a long time. It was hard to reconcile with his idea of what Julia Zimmerman was involved in. So far he had pictured her as interested in obscure mathematical objects like the Zeta Function. The Internet seemed too "earthy" a topic for her.

He looked across at Ruth. "How interested is your sister in computers?"

"She's fascinated by them," Ruth said. "At least as far as they are a means to her ends. She once called them a mathematical telescope."

"Interesting metaphor."

"I think she meant that a computer can be used to see parts of the mathematical universe that would be otherwise undetectable."

There was an abstract of the speech available, and Gideon opened it.

"Has the term 'virus' stopped being metaphorical?" Gideon read. "With the increase in complexity of the

Internet, there has been an increase in the 'size' of the environment that can host uncontrolled entities. An average personal computer is packed with so much data that it is easy for foreign bits of code to hide undetected, and when it is connected to a network, the environment is vast. Security against computer viruses, because of their constant proliferation, has had to concentrate more and more on preventing the harmful effects of these viruses, and less on preventing the infection of the system. It is possible for a 'benign' virus, a virus that conducts no discernible attacks on its host, to propagate unimpeded. Evolution forces the eventual existence of such 'benign' viruses."

Gideon looked at the abstract and thought about what the old guy had told them about Julia's work for the NSA. Information warfare he said, military-grade viruses . . .

"Maybe this is what she was really working on," Gideon whispered. If it was, he wondered what it meant. Was she actually working on some terrorist weapon? Why?

On the other end of the secure phone line, Emmit D'Arcy said, "What've you got?"

Colonel Mecham looked at the papers that'd just been delivered to his desk. "We have a flag from the New York Public Library."

"The library?"

"Mother filtered out a keyword search originating from one of the public terminals. About Zimmerman. There's a good chance it's Malcolm." Mecham cleared his throat. "I've ordered a team in to extract him."

There was a pause on the other end of the line. Eventually D'Arcy said, "Did I hear you right?"

"This was time sensitive. The search was in progress as Mother flagged it. I had to act immediately."

"I see." D'Arcy's voice became colder. "When this is over, we'll have a talk about this, Colonel Mecham."

I'm sure we will, Mecham thought. Probably in front of a Senate hearing. "Yes, sir," he hung up the phone and shook his head. He looked up at the man sitting across from him. "There we go," he said. "That's my career."

General Adrian Harris shook his head. "It has to be done. This situation is too dangerous to have a loose cannon out there. He's served his purpose, drawing the IUF out of the woodwork." The General stood up and said, "Don't worry, son. You did your duty."

Mecham watched as the Chairman of the Joint Chiefs left his office. The door closed silently behind him.

He had been on the computer long enough for his eyes to begin to hurt. He leaned back and let his gaze drift.

"So," Ruth asked, "are you any closer?"

"I don't know." He had spent hours scanning documents, some of them way beyond his level of understanding. He had even found a description of the program Julia left on her own PC. It was a "game" called Life that seemed to have originated on a checkerboard. It was played on a grid, and each turn, every cell on the grid is turned on or off—lives or dies—based on the number of neighboring living cells. The rules of the game were simple, four lines long, but the complexities of the patterns involved could be astounding.

The game of life, in the decades since its invention, had spawned a whole mathematical discipline around the study of what was called cellular automata. There were people writing theses on the properties of various arrangement of cells—there were patterns that could "move" across the grid, essentially unchanged in form, there were other patterns that could repeatedly build other patterns. All from a set of rules that could fit on a business card.

Why leave that behind? Gideon pictured the way the pattern had erupted across the screen of Julia's computer, and then dissolved off into nothing. Why?

He had found quite a few traces of Julia Zimmerman in articles across the Internet, all predating her work for the government. While there was no question about her mathematical genius, she more often gave talks about the Evolutionary Algorithm than the Theorems she was trying to solve with it. When he first heard about what the ET Lab was doing, he'd thought that the computers were simply a means to work on the problems she was trying to solve.

More and more, it seemed that those problems were an excuse to work with the computers, and the opportunities that they opened up for her.

Gideon looked up at one of the chandeliers above the main reading room, watching as the late morning sunlight caught it. "You think she saw the computers as a window on that pure mathematical world she

believed in?"

"That's the way she described it to me, back when she was going to college."

Gideon looked at the description of "Life," and thought of Julia's own computer. Why leave it there unless it was some sort of message? A message to the people she knew would be going over her hard drive with a fine-toothed comb.

'"This is what I'm doing,'" Gideon said, still staring at the chandelier. '"This is what I'm interested in.'"

"What?"

"That's what she was telling them. I have a feeling about this. I think she might have modified her thinking about computers, about the data inside them, at least."

"What do you mean?"

"I don't think she sees them as a window on her mathematical world," Gideon turned to face Ruth. Her face was half shadow and half rose from the ambient light reflecting off the woodwork. "I think she might see them as that world."

Ruth looked at him. "Come on, that's crazy. Julie knew—even when she talked about God in the numbers—that we're only talking about mental constructs here. She knew that there could never be a 'real' physical representation of it. There's even a theorem that proves that we can't have a complete picture of the mathematical world."

"What's that?"

"I don't quite understand it, but she told me about it the last time she talked to me about her work. It's called Godel's Incompleteness Theorem—I think it says that it's impossible to prove all true statements in a logical system, even if the system is consistent. Julia thought that it proved that we can only glimpse the perfection of the mathematical."

Gideon nodded. "What that means is that there's still room for faith in Julia's religion."

Ruth stopped short. "What do you mean?"

"What's faith, but the acceptance that some things are true despite lacking the proof for them? Despite the impossibility of proving them . . . When did Julia tell you about this?"

"Just before she went to MIT. What are you thinking?"

Gideon looked at the computer in front of him, then past it at the series of terminals ranged along the reading tables. It's gotten to the point where we see them, but we don't see them. The computer was ubiquitous, everywhere . . . and most of them were connected to each other. The space, the environment that existed inside those machines, was just on the edge of comprehension. It was very easy to think of it as another world, an alternate universe.

And if he was thinking along these lines with just a brush against Julia Zimmerman's ideas, what was the impact of the woman herself? Someone everyone acknowledged as a genius . . .

"She stopped talking to you about the time she started working at MIT, didn't she?"

Ruth nodded.

"You said she took a page from the Greeks . . ."

"Yes, the Pythagoreans. Where are you going with all this?"

Gideon pulled a paper out of his pocket. It was the copy of the campus paper he had taken from MIT. He showed it to Ruth, reading the caption, '"Assault on Mt. Riemann; Drs. Nolan and Zimmerman stand with their New Pythagorean Order—members of the ET Lab— show a printout of a possible proof,' have you heard that phrase before? 'New Pythagorean Order?'"

Ruth shook her head.

Gideon bent over the computer and called up a new search. The term "Pythagorean Order" brought a series of documents. The content wasn't that surprising. . .

"According to Aristotle, the Pythagorean Order, first to develop the science of mathematics, revered number as the origin of the cosmos. The Order, a religious cult founded in Croton on the coast of Italy around 530 BC, was founded by Pythagoras of Samos, a mathematician, philosopher, and religious leader."

Gideon looked at the screen and said, "Nolan said that they were almost a cult."

"I'm not following you."

"I'm talking about what every religious leader needs." Gideon turned and looked at Ruth. "Disciples."

"Are you serious?"

Gideon took the article back and started hunting down some on-line telephone directories. "She told you her beliefs; she doesn't seem shy about voicing them."

"Yes, but I mean, they're off the wall. What are you talking about? A cult at MIT?"

Gideon started getting phone numbers matching the names in the article. He scribbled on the article as he paged through a series of names. "Is it so unlikely that she'd manage to find people who'd give some kind of weight to her beliefs? Look at how she left MIT. She erased all the ongoing work at the ET Lab. Could she do it all herself? We're talking about the efforts of a dozen people. Wouldn't that require some complicity from the people who worked in the lab?"

"I'm certain that a few people supported her . . ."

"The only member of the ET Lab who's still there was the one tenured professor. Not a one ended up with a teaching position, or even continued their studies there past the demise of the lab." Gideon shook his head. "And I know at least one of those people is helping Zimmerman right now." Gideon scribbled a final number and stood up. "Come on, I need to get to a phone."

Ruth stood up, and they started heading toward the end of the reading room. They had only gone a few feet when Gideon slowed to a stop. There were two men standing at the end of the room in front of them, both converging on the exit.

Gideon turned around to head toward the other end of the room, and another set of doors. At that end of the room, there were two others. A pair of guys, one who'd been sitting at a terminal, another who had been reading at a table—both were just standing.

Gideon had been keeping an eye out for people who were out of place. But these guys hadn't been. They'd been filtering into the reading room, one at a time, over the past half hour. They were all dressed differently, one was in a suit, another in jeans and a flannel shirt, another in Dockers and a turtleneck. Gideon kept turning and Ruth gripped his arm.

Everyone who had been in the room with them—reading or perusing the computer network—they were all standing, facing the two of them. Gideon put an arm around Ruth, as if he could protect her from the people surrounding them.

Of the people surrounding them, one of the two or three women stepped up toward them. She wore a navy suit and Gideon found himself looking for where the gun was holstered. She stopped about twenty feet away.

"Gideon Malcolm, Ruth Zimmerman?" she asked. It was just barely a question.

"Who are you?" Gideon asked.

"Tracy Davis, I'm a federal agent. I'm a negotiator."

"Can I see an ID?"

Davis obliged by pulling one out and opening it for him. Gideon looked and noted, with some irony, that she was Secret Service.

"What's to negotiate?" Gideon said. "You have us surrounded."

"I'm going to try and make sure no one gets hurt." Davis smiled weakly, and Gideon could tell, by looking in her eyes, that she was unsure how this was gong to go down. They were treating this like a hostage situation, which suddenly made Gideon feel very nervous.

"No one's going to get hurt," Gideon said. He said it to reassure Ruth and himself as much as the folks surrounding them. "I'm letting her go now, okay?"

He waited for Davis to say, "Okay," before he started moving, very slowly. Right now there was no doubt in his mind that there were snipers in place somewhere beyond the arched windows that overlooked the reading room. None of whom he wanted to spook.

Once his arm was free and Ruth was standing beside him, he held his hands out in front of him. He said, "I have a gun in my pocket. Are people going to be nervous if I hand it over?"

Davis pulled out a walkie-talkie that was the size of a small cellular phone. She spoke quietly back and forth for a few moments, then she said, "Is it in your jacket?"

Gideon nodded.

"What you want to do is take off the jacket and toss it over here by me."

At this point, Ruth said, "What's going on?"

Gideon shook his head as he Slowly began removing his jacket. "You wanted to talk to the Feds? Here they are."

They were both cuffed by the Feds and led out of the library. As they took him out, Gideon had a good look at how serious they were. As they passed out of the reading room, they entered a hallway that was filled with NYPD guys in ballistic helmets and flak jackets.

When they stepped out on to Fifth Avenue, the street had turned into a parking lot for cop cars, sedans, and two SWAT team vans. Gideon saw press crews, but they were so far away that he doubted that they could see anything.

Davis handed him off to a dark guy in a suit, and he hustled him into one of the sedans. The last Gideon saw of Ruth, she was shoved into the back of a different sedan. Gideon asked the driver, "So, what federal agency are you with?"

The guy didn't answer him. He stared straight ahead, and Gideon could only get a good view of his crew cut and a strip of his face in the rearview mirror. Gideon looked over the man's shoulder, at his hands. He saw an academy ring.

"Marine, huh?"

"I'm not permitted to speak with you, sir."

Gideon kept trying to get the guy to talk, but true to his word, the Marine didn't say a single word more. Eventually, he drove off, following two other sedans down Fifth. They were the first cars to leave the scene.

Gideon expected the reporters to converge, but the cops held the press, and everyone else, away from the small motorcade. As they left, Gideon looked back and saw what had to be a staged disturbance at the front of the library. Several men were being escorted by the NYPD cops, kicking and struggling, despite being chained and carried between four cops in riot gear. Designed to draw attention away from the anonymous sedans.