But it was a wire that crossed the air gap.

That would do it. One of Sam's special tricks was a clever bit of software that would break IP packets into tiny bits, attach them to genuine e-mails, and rea.s.semble them at the other end, creating an invisible connection between the two computers that flowed beneath the constant current of e-mail messages between the two networks.

It was like writing secret messages, one word at a time, underneath stamps on envelopes and posting them one after the other. At the receiving end, someone had to a.s.semble the words back into a full sentence.

He called it Cross Fire, for no particular reason.

He slipped his software onto the NetOp e-mail server by launching a Denial of Service (DoS) attack from a small server farm in the Netherlands that he had compromised over a year before.

While the systems and their administrators responded to that, he slid Cross Fire quietly onto the server using a variant of the old Metasploit tool.

Now for the e-mail server.

An Uninterruptible Power Supply, a UPS, protected it against power outages. The UPS was connected to the server by an old-fashioned serial cable, which in emergencies could send a shutdown command to the server. Furthermore, the company that installed the UPS monitored it so they could run diagnostics and respond to any problems in the device.

Sam crept carefully into the network of the UPS supplier and slid slowly down the wire to the UPS device itself.

It wasn't enough to load Cross Fire onto the server, though; it had to be run. The program had to be executed, and he couldn't do that through a serial connection.

He encased Cross Fire in a self-executing sh.e.l.l and renamed it to that of a common internal Windows program. Someone inside the White House would unwittingly run the program that would complete the circuit and give Sam access, through the e-mail connection, to the heart of the U.S. government.

Through the serial connection, he copied the file into the Operating System folder of the e-mail server and closed out of the UPS and the UPS company network.

Now there was nothing more he could do. It was up to the staff at the White House to open the door and let him in.

7

NEOH-CK

He checked his watch a couple of times, not worried but a little nervous. If Cross Fire was detected, then he was sunk. If it simply wasn't activated, then he would miss the convention.

To pa.s.s the time, he alt-tabbed back to see Ursula.

The next set of neuro-exercises involved loading a program, such as Photoshop, while thinking about that program. Very soon he could open and close programs, activate commands and functions, and even move things around on a page, all without touching the keyboard. Next, Ursula asked him to visualize each key on the keyboard in turn, while pressing it. That was easy enough.

A short while later, he was in the middle of an exercise that involved him thinking of a word, then seeing it appear on the screen, when a pop-up message alerted him that Cross Fire was now active.

"See you soon, Ursula," he whispered, and minimized her again.

Someone had activated Cross Fire, opening up a tiny pathway onto one of the e-mail servers on the White House network.

He slipped Ghillie onto the machine, and it lay there for a while, un.o.bserved but observing.

The amount of data traffic was amazing but not unexpected for the nerve center of a world superpower.

Sam did not move at all, just watched for intrusion detectors or security spiders. The spiders were everywhere, constantly crawling through the White House network. They pa.s.sed over him harmlessly, though, without seeing.

He spun a small data-web on one branch of the network, blocking packets from getting through. Not many, and they would get through on the retry, but enough for him to gauge how the network reacted.

The White House network was monitored by special software called Therminator. It presented the network as a thermal image, with any problems showing up as hot spots. But there had to be a built-in tolerance level, Sam figured; otherwise, every slight networking issue would set off alarm bells.

No alarms went off. No searchlights swept the area. A small packet loss was within the tolerance of the network, it seemed, as it should be.

He extended a probe, a clever device that emulated broken TCP/IP packets and simulated data loss, which would be ignored by Therminator. He scanned the disk structure of the big server.

There were over thirty disk drives attached to the machine. He scrolled through the list of drives, wondering where to start.

One caught his eye. A tiny drive, just half a gigabyte. A fraction of the size of the others, which was why he noticed it. It was labeled "NHC."

It took a moment before that clicked.

NHC! Con! It had to be, he thought as he accessed the contents of the drive itself.

The hackers had set up their own part.i.tion on one of the White House central server's disks and were using that for their meetings. On the drive was just a single file. An executable. A program. That would be the online-forum software, he guessed.

His watch said it was 8:15. Too early. Not that he minded being early, but there might be risks in logging on too soon. The longer he was logged in, the greater the chance of being caught.

He alt-tabbed to bring the Neuro-Sensor software to the front again, but even as he did so, he realized something strange. For the last twenty minutes, he had been crawling around inside the computer network of the White House. He had activated programs, spun data-webs, even written short bursts of code.

But he hadn't touched the mouse or the keyboard at all.

Ursula had a whole bunch of other exercises to improve his skills, but he was getting impatient, so he bypa.s.sed them and loaded the next module.

"Neuro-visualization," Ursula told him smoothly. "The neuro-sensors in your headset are also transmitters. They not only pick up signals from your brain, but they also can feed sounds and images into your brain by stimulating brain waves in your visual and auditory cortices."

"Cool," Sam said, nervously flicking a glance at his watch. It was 8:16. Only a minute had pa.s.sed.

"Close your eyes," Ursula said. "I am going to send an image to you now. Nothing fancy, just a red triangle. Relax and allow your brain to receive and interpret the image. If you open your eyes, the feed will automatically shut off. This is a safety mechanism to ensure you do not overload the visual receptors in your brain with information from two different sources."

Sam closed his eyes.

"Visual feed starting now," Ursula said.

A blurry red dot appeared behind Sam's eyes.

"It had better get better than this," he muttered.

"You should now be seeing a fuzzy red shape," Ursula said. "Focus on it; try and draw it toward you."

Sam focused, imagining himself speeding toward the red nothingness. It began to grow in size.

After a moment, it filled almost half of his vision, and although still out of focus, it was clearly a large red triangle.

"Concentrate on the triangle; try and bring it sharply into focus. As it changes, I want you to press the Plus and Minus keys on your keyboard. If it gets clearer, press Plus. If it becomes less distinct, then press Minus. When it is perfectly sharp, press the s.p.a.ce bar."

Sam waited until the edges were sharp and clear, then pressed the s.p.a.ce bar.

"Okay," she said. "Now for color. I am going to show you a series of color images. When you see the one that has a red dot at the top, a blue dot at the left, and a green dot on the right, then press the s.p.a.ce bar."

It was the first image.

"Good. Now I am going to send you a color image. If you can identify the image, then type the name on the screen," she said, and added, "with your mind, of course."

Sam opened his eyes for a moment to check his watch (8:53 p.m.), and when he shut them, a huge, clear image of the famous da Vinci painting Mona Lisa Mona Lisa was hanging right in front of him, occupying all of his vision. It was bigger and clearer than he could have ever dreamed possible, and he realized that the image was being beamed directly into his visual cortex. was hanging right in front of him, occupying all of his vision. It was bigger and clearer than he could have ever dreamed possible, and he realized that the image was being beamed directly into his visual cortex.

Mona Lisa, he thought, and the words appeared over the top of the picture. The bemused smile on the face in the painting broke into a grin, and Mona Lisa said, with Ursula's voice, "Congratulations. You are correct. You are now ready to use your neuro-connector to view and operate your computer. Have fun!"

The painting disappeared, replaced by his normal Windows background and icons. He opened a few programs and closed them again just to prove he could do it. He opened a word processor and typed a few sentences with his mind. He ran an MP3 file and was astounded to hear the music inside his head. He tried the same with a video and was rewarded by the movie starting to play in a small window.

He closed it and glanced at the clock in the lower right corner of his screen (did you call it a screen when it was inside your head?) and noticed that it was 8:59 p.m.

"Dinnertime," he said out loud.

Without touching the mouse or the keyboard or looking at the LCD screen of his laptop, he ventured back into the electronic corridors of the White House.

He checked the clock in the bottom right corner again. 9:00 p.m.

Open, he thought, staring at the file.

It opened.

There was a brief second or two of a standard hourgla.s.s; then the software took over the whole of his screen, the whole of his vision vision!

It opened into an image, a virtual version of the White House. He was somewhere in the grounds of the big building. It was a sunny day, and the gra.s.s was green underfoot. In front of him, a fountain, surrounded by a low hedge, sprayed virtual water up into the air, digital droplets sparkling in the bright sun before cascading back to earth.

Now, finally, he understood what Skullface had meant. It wasn't just an online forum; it was virtual-meeting software, where their avatars would see and talk to each other in a cyberworld. Like Third Life. They would probably meet in the Oval Office itself, he thought. No, Skullface said dinner-it would be in the formal dining room.

By thinking himself forward, he began to move, skirting around the side of the fountain toward the front doors.

He moved across a roadway, past the white pillars, up a flight of stairs toward the huge double doors of the White House, which were set in an arched entranceway.

He imagined the doors opening, but they did not.

He opened his eyes and tried clicking on the doors with his mouse, but they remained solidly closed.

He closed his eyes again and looked around.

To the right of the doors, conveniently placed at head height on the door frame, was a black rectangular plastic shape with a white b.u.t.ton in the center.

A doorbell.

Sam chuckled to himself. So simple. The final hurdle was not a hurdle at all.

At the start it had seemed impossible, yet here he was, at the front door of the White House, about to embark on an incredible new adventure. What would he learn? Who would he meet?

He took a deep breath and clicked on the doorbell.

A sound intruded and he opened his eyes with a start, shutting off the audiovisual feed from the neuro-connector. The White House doors and the doorbell were still there, though, staring at him from the laptop screen.

Surely he had just imagined that sound.

He kept his eyes open and tried again, this time preferring traditional methods. He reached out and grasped his mouse with his right hand and moved it over to the doorbell.

Drawing in his breath again, he clicked on the b.u.t.ton a second time.

And jumped out of his chair with sudden, terrible knowledge and fear.

Outside his bedroom, past the kitchen, where his mother was preparing dinner, at the end of the hallway, at the front door of their sixth-floor apartment, the doorbell rang again.

8

KIWI

Sam lay on the lumpy mattress on the metal-framed bunk, staring blankly at the ceiling of his cell and watching fuzzy specks of eyeball dust float around like microbes in a solution on a microscope slide.

He felt he was going mad. Three days locked in a cell they called a bedroom. But it had wire mesh on the windows, and the door was permanently locked, which seemed more like a prison cell to Sam.

Three days ago, he had raced down the hallway to the front door of their apartment. Terrified of opening the door, but even more terrified of his mother opening it first.

The man standing there wore tactical black SWAT-type coveralls and a Kevlar vest. A pistol in a black leather holster was strapped halfway down his thigh. He was in his late twenties. Not short, but not tall either. His hair was slicked back in a style reminiscent of old fifties rock 'n' rollers, as if to make him taller, and he wore dark aviator-style mirrored gla.s.ses, which he removed as Sam opened the door.

The man was flanked by two others in identical uniforms but who had automatic rifles slung across their chests. They stood back from the doorway, against the wall on the opposite side of the hall, and their gazes flicked left and right as if they were expecting trouble.

All three of them wore flesh-colored earpieces with a curly wire that disappeared around the back of their necks.

Through a half-open door on the other side of the corridor, Louis, the Neanderthal fourteen-year-old, watched, wide-eyed.

"Sam Wilson?" the first man asked.

Sam nodded mutely.

"I'm Special Agent Ranger Tyler from the Department of Homeland Security, Cyber Defense Division. I am placing you under arrest on suspicion of government network infiltration and sabotage. You have the right..."

Sam didn't get to hear his rights. Not just then, anyway.