At 0654 hours at the vital U.S. Army, Air Force, and Naval installation on Diego Garcia, the officer commanding the shift at the control tower was gazing out the windows as the morning sun illuminated the warm blue waters of Emerald Bay on the lagoon side of the U-shaped atoll and wishing he were off duty. His eyes blinked slowly, and his mind wandered.

The U.S. Navy Support Facility, the host command for this strategically located, operationally invaluable base, kept all of them busy with its support of sea, air, and surface flight operations. The payback was the island itself, a remote place of sweeping beauty, where the easy rhythms of routine duty lulled ambition.

He was seriously contemplating a long swim the instant he was off duty when, one minute later, at 0655 hours, the control tower lost contact with the base's entire airborne fleet of B-1B, B-52, AWACS, P-3 Orion, and U-2 aircraft, on a variety of missions that included hot-button reconnaissance and antisubmarine and surveillance support.

The tropical lagoon vanished from his mind. He bawled orders, pushed a technician from one of the consoles, and started diagnostics. Everyone's attention was riveted on the dials, readouts, and screens as they battled to regain contact.

Nothing helped. At 0658, in a controlled panic, he alerted the base's commanding officer.

At 0659, the commanding officer informed the Pentagon.

Then, oddly, inexplicably, at 0700, five minutes after they had mysteriously disappeared, all communications with the aircraft returned at the precise same second.

Fort Collins, Colorado
Monday, May 5

As the sun rose over the vast prairie to the east, the rustic Foothills Campus of Colorado State University glowed with golden light. Here in a state-of-the-art laboratory in a nondescript building, Jonathan ("Jon") Smith, M.D., peered into a binocular microscope and gently moved a finely drawn glass needle into position. He placed an imperceptible drop of fluid onto a flat disk so small that it was no larger than the head of a pin. Under the high-resolution microscope, the plate bore a striking -- and seemingly impossible -- resemblance to a circuit board.

Smith made an adjustment, bringing the image more clearly into focus. "Good," he muttered, and smiled. "There's hope."

An expert in virology and molecular biology, Smith was also an army medical officer -- in fact, a lieutenant colonel -- temporarily stationed here amid the towering pines and rolling foothills of Colorado at this Centers for Disease Control (CDC) facility. On unofficial loan from the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), he was assigned basic research into evolving viruses.

Except that viruses had nothing to do with the delicate work he was watching through the microscope this dawn. USAMRIID was the army's foremost military medical research facility, while the CDC was its highly touted civilian counterpart. Usually they were vigorous rivals. But not here, not now, and the work being done in this laboratory had only a peripheral connection to medicine.

Smith was part of a little-known CDC-USAMRIID research team in a worldwide race to create the world's first molecular -- or DNA -- computer, therefore forging an unprecedented bond between life science and computational science. The concept intrigued the scientist in Smith and challenged his expertise in the field of microbiology. In fact, what had brought him into his lab at this ungodly early hour was what he hoped would turn out to be a breakthrough in the molecular circuits based on special organic polymers that he and the other researchers had been working night and day to create.

If successful, their brand-new DNA circuits could be reconfigured many times, taking the joint team one step closer to rendering silicon, the key ingredient in the wiring of current computer circuit boards, obsolete. Which was just as well. The computer industry was near the limits of silicon technology anyway, while biological compounds offered a logical -- although difficult -- next step. When DNA computers could be made workable, they would be vastly more powerful than the general public could conceive, which was where the army's, and USAMRIID's, interests came in.

Smith was fascinated by the research, and as soon as he had heard rumors of the secret joint CDC-USAMRIID project, he had arranged to be invited aboard, eagerly throwing himself into this technological competition where the future might be only an atom away.

"Hey, Jon." Larry Schulenberg, another of the project's top cell biologists, rolled into the empty laboratory in his wheelchair. "Did you hear about the Pasteur?"

Smith looked up from his microscope. "Hell, I didn't even hear you open the door." Then he noticed Larry's somber face. "The Pasteur," he repeated. "Why? What's happened?" Like USAMRIID and the CDC, the Pasteur Institute was a world-class research complex.

In his fifties, Schulenberg was a tan, energetic man with a shaved head, one small diamond earring, and shoulders that were thickly muscled from years of using crutches. His voice was grim. "Some kind of explosion. It's bad. People were killed." He peeled a sheet from the stack of printouts on his lap.

Jon grabbed the paper. "My God. How did it happen? A lab accident?"

"The French police don't think so. Maybe a bomb. They're checking out former employees." Larry wheeled his chair around and headed back to the door. "Figured you'd want to know. Jim Thrane at Porton Down e-mailed me, so I downloaded the story. I've got to go see who else is here. Everyone will want to know."

"Thanks." As the door closed, Smith read quickly. Then, his stomach sinking, he reread...

Paris -- A massive explosion killed at least 12 people and shattered a three-story building housing offices and laboratories at the venerable Pasteur Institute at 10:52 P.M. here last night. Four survivors in critical condition were found. The search continues in the rubble for other victims.

Fire investigators say they have found evidence of explosives. No person or group has claimed responsibility. The probe is continuing, including checking into recently released employees.

The identified survivors include Martin Zellerbach, Ph.D., a computer scientist from the United States, who suffered head injuries....

Smith's heart seemed to stop. Martin Zellerbach, Ph.D., a computer scientist from the United States, who suffered head injuries. Marty? His old friend's face flashed into Jon's mind as he gripped the printout. The crooked smile, the intense green eyes that could twinkle one moment and skitter off, lost in thought or perhaps outer space, the next. A small, rotund man who walked awkwardly, as if he had never really learned how to move his legs, Marty had Asperger's Syndrome, a rare disorder at the less severe end of the autism spectrum. His symptoms included consuming obsessions, high intelligence, crippling lack of social and communications skills, and an outstanding talent in one particular area -- mathematics and electronics. He was, in fact, a computer genius.

A worried ache settled in Smith's throat. Head injuries. How badly was Marty hurt? The news story did not say. Smith pulled out his cell phone, which had special scrambler capabilities, and dialed Washington.

He and Marty had grown up together in Iowa, where he had protected Marty from the taunts of fellow students and even a few teachers who had a hard time believing anyone so smart was not being intentionally rude and a troublemaker. Marty's Asperger's was diagnosed when he was older and at last he was given the medication that helped him function with both feet firmly attached to the planet. Still, Marty hated taking meds and had designed his life so he could avoid them as often as possible. He did not leave his cozy Washington, D.C., bungalow for years at a time. There he was safe with the cutting-edge computers and the software he was always designing, and his mind and creativity could soar, unfettered. Businessmen, academicians, and scientists from around the globe went there to consult him, but never in person, only electronically.

So what was the shy computer wizard doing in Paris?

The last time Marty consented to leave was eighteen months ago, and it was far from gentle persuasion that convinced him. It was a hail of bullets and the beginning of the near catastrophe of the Hades virus that had caused the death of Smith's fiancée, Sophia Russell.

The phone at Smith's ear began to ring in distant Washington, D.C., and at the same time he heard what sounded like a cell phone ringing just outside his laboratory door. He had an eerie sense...

"Hello?" It was the voice of Nathaniel Frederick ("Fred") Klein.

Smith turned abruptly and stared at his door. "Come in, Fred."

The chief of the extremely secret Covert-One intelligence and counterintelligence troubleshooting organization stepped into the laboratory, quiet as a ghost, still holding his cell phone. "I should've guessed you would've heard and called me." He turned off his phone.

"About Mart? Yes, I just read about the Pasteur. What do you know, and what are you doing here?"

Without answering, Klein marched past the gleaming test tubes and equipment that crowded the line of lab benches, which soon would be occupied by other CDC-USAMRIID researchers and assistants. He stopped at Smith's bench, lifted his left hip, and sat on the edge of the stone top, arms crossed, face grim. Around six feet tall, he was dressed as usual in one of his rumpled suits, this one brown. His skin was pale; it rarely saw the sun for any length of time. The great outdoors was not where Fred Klein operated. With his receding hairline, wire-rimmed glasses, and high, intelligent forehead, he could be anything from book publisher to counterfeiter.

He contemplated Smith, and his voice was compassionate as he said, "Your friend's alive, but he's in a coma. I won't lie to you, Colonel. The doctors are worried."

For Smith, the dark pain of Sophia's death could still weigh heavily on him, and Marty's injury was bringing it all back. But Sophia was gone, and what mattered now was Marty.

"What the hell was he doing at the Pasteur?"

Klein took his pipe from his pocket and brought out his tobacco pouch. "Yes, we wondered about that, too."

Smith started to speak again... then hesitated. Invisible to the public and to any part of the government except the White House, Covert-One worked totally outside the official military-intelligence bureaucracy and far from the scrutiny of Congress. Its shadowy chief never appeared unless something earthshaking had happened or might happen. Covert-One had no formal organization or bureaucracy, no real headquarters, and no official operatives. Instead, it was loosely composed of professional experts in many fields, all with clandestine experience, most with military backgrounds, and all essentially unencumbered -- without family, home ties, or obligations, either temporary or permanent.

When called upon, Smith was one of those elite operatives.

"You're not here because of Marty," Smith decided. "It's the Pasteur. Something's going on. What?"

"Let's take a walk outside." Klein pushed his glasses up onto his forehead and tamped tobacco into his pipe.

"You can't light that here," Smith told him. "DNA can be contaminated by airborne particles."

Klein sighed. "Just one more reason to go outdoors."

Fred Klein -- and Covert-One -- trusted no one and nothing, took nothing for granted. Even a laboratory that officially did not exist could be bugged, which, Smith knew, was the real reason Klein wanted to leave. He followed the intelligence master out into the hall and locked his door. Side by side, they made their way downstairs, past dark labs and offices that showed only occasional light. The building was silent except for the breathy hum of the giant ventilation system.

Outside, the dawn sunlight slanted low against the fir trees, illuminating them on the east with shimmering light while on the west they remained tarry black, in shadows. High above the campus to the west towered the Rocky Mountains, their rough peaks glowing. The valleys that creased the slopes were purple with night's lingering darkness. The aromatic scent of pine filled the air.

Klein walked a dozen steps from the building and stopped to fire up his pipe. He puffed and tamped until clouds of smoke half-hid his face. He waved some of the smoke away.

"Let's walk." As they headed toward the road, Klein said, "Talk to me about your work here. How's it going? Are you close to creating a molecular computer?"

"I wish. The research is going well, but it's slow. Complex."

Governments around the world wanted to be the first to have a working DNA computer, because it would be able to break any code or encryption in a matter of seconds. A terrifying prospect, especially where defense was concerned. All of America's missiles, secret systems at NSA, the NRO's spy satellites, the entire ability of the navy to operate, all defense plans -- anything and everything that relied on electronics would be at the mercy of the first molecular computer. Even the largest silicon supercomputer would not be able to stop it.

"How soon before the planet sees an operational one?" Klein wanted to know.

"Several years," Smith said without hesitation, "maybe more."

"Who's the closest?"

"Practical and operational? No one I've heard of."

Klein smoked, tamped down his burning tobacco again. "If I said someone had already done it, who'd you guess?"

Precursor prototypes had been built, coming closer to practicality each year, but an actual, complete success? That was at least five years away. Unless... Takeda? Chambord?

Then Smith knew. Since Klein was here, the clue was the Pasteur. "Émile Chambord. Are you saying Chambord is years ahead of the rest of us? Even ahead of Takeda in Tokyo?"

"Chambord probably died in the explosion." Klein puffed on his pipe, his expression worried. "His lab was completely destroyed. Nothing left but shattered bricks, singed wood, and broken glass. They've checked his home, his daughter. Looked everywhere. His car was in the Pasteur parking lot, but they can't find him. There's talk."

"Talk? There's always talk."

"This is different. It comes from top French military circles, from colleagues, from his superiors."

"If Chambord were that near, there'd be more than talk. Someone knew."

"Not necessarily. The military checked in with him regularly, but he claimed he was no farther along than anyone else. As for the Pasteur itself, a senior researcher of Chambord's stature and tenure doesn't have to report to anyone."

Smith nodded. This anachronism was true at the renowned institute. "What about his notes? Records? Reports?"

"Nothing from the last year. Zero."

"No records?" Smith's voice rose. "There have to be. They're probably in the Pasteur's data bank. Don't tell me the entire computer system was destroyed."

"No, the mainframe's fine. It's located in a bomb-proof room, but he hadn't entered any data in it for more than a year."

Smith scowled. "He was keeping longhand records?"

"If he kept any at all."

"He had to keep records. You can't do basic research without complete data. Lab notes, progress sheets. Your records have to be scrupulous, or your work can't be verified or reproduced. Every blind alley, every mistake, every backtrack has to be chronicled. Dammit, if he wasn't saving his data in the computer, he had to be keeping it longhand. That's certain."

"Maybe it is, Jon, but so far neither the Pasteur nor the French authorities have found any records at all, and believe me, they've been looking. Hard."

Smith thought. Longhand? Why? Could Chambord have gotten protective once he realized he was close to success? "You figure he knew or suspected he was being watched by someone inside the institute?"

"The French, and everyone else, don't know what to think," Klein said.

"He was working alone?"

"He had a low-level lab assistant who's on vacation. The French police are searching for him." Klein stared toward the east, where the sun was higher now, a giant disk above the prairie. "And we think Dr. Zellerbach was working with him, too."

"You think?"

"Whatever Dr. Zellerbach was doing appears to have been completely unofficial, almost secret. He's listed only as a 'general observer' with Pasteur security. After the bombing, the police immediately went to his hotel room but found nothing useful. He lived out of one suitcase, and he made no friends either there or at the Pasteur. The police were surprised by how few people actually recalled him."

Smith nodded. "That's Marty." His reclusive old friend would have insisted on remaining as anonymous as possible. At the same time, a molecular computer that was near fruition was one of the few projects that might have seduced him from his determined isolation in Washington. "When he regains consciousness, he'll tell you what Chambord's progress was."

"If he wakes up. Even then it could be too late."

Jon felt a sudden anger. "He will come out of the coma."

"All right, Colonel. But when?" Klein took the pipe from his mouth and glared. "We've just had a nasty wake-up call that you need to know about. At 7:55 Washington time last night, Diego Garcia Island lost all communications with its aircraft. Every effort to revive them, or trace the source of the shutdown, failed. Then precisely five minutes later, communications were restored. There were no system malfunctions, no weather problems, no human error. Conclusion was it had to be the work of a computer hacker, but no footprints were found, and every expert short of heaven says no existing computer could've pulled it off without leaving a trace."

"Was there damage?"

"To the systems, no. To our worry quotient, one hell of a lot."

"How does the timing compare to when the Pasteur was bombed?"

Klein smiled grimly. "A couple of hours later."

"Could be a test of Chambord's prototype, if he had one. If someone stole it."

"No kidding. The way it stands, Chambord's lab is gone. He's dead or missing. And his work is destroyed... or missing."

Jon nodded. "You're thinking the bomb was planted to hide his murder and the theft of his records and prototype."

"An operational DNA computer in the wrong hands is not a pretty picture."

"I was already planning to go to Paris, because of Marty."

"I thought so. It's a good cover. Besides, you'll have a better chance of recognizing a molecular computer than anyone else in Covert-One." Klein raised his anxious gaze to stare out across the enormous prairie sky as if he could see ICBMs raining down. "You've got to find out whether Chambord's notes, reports, and data were destroyed, or whether they were stolen. Whether there really is a functional prototype out there somewhere. We'll work the usual way. I'll be your only contact. Night or day. Whatever you need from any part of the government or military on both sides of the pond, ask. But you must keep a lid on it, understand? We don't want any panic. Worse, we don't want an eager Second or Third World country cutting a unilateral deal with the bombers."

"Right." Half the nonadvanced nations had little love for the United States. Neither did the various terrorists who increasingly targeted America and Americans. "When do I leave?"

"Now," Klein said. "I'll have other Covert-One experts on it, of course. They'll be following other leads, but you'll be the main thrust. The CIA and FBI have sent people out, too. And as for Zellerbach, remember I'm as concerned as you. We all hope he regains consciousness quickly. But there may be damn little time, and many, many other lives are at stake."