'Actually I'm not okay, Agent Flaherty,' Stokes said, mopping his chin, then chucking the vulgar handkerchief in the waste-basket beneath his desk. 'Which makes this your lucky day.'

'How so?' Flaherty asked.

'You see, I'm not just a smart man. By tomorrow, I'll be a dead man. Which means I have no reason to hide anything from you. So you'll get your answers. All of them. You'll hear things you'll wish you never heard. But first I'll need to show you a few things to help you sew your thread.' He rose to his feet, came around the desk and hesitated. 'And you're wrong about one thing.'

'What might that be?'

'The cave is is the common thread.' the common thread.'

59.

Randall Stokes ushered the two guests across the office to an ordinary-looking door centred between two floor-to-ceiling bookcases. He punched a pa.s.s code into a keypad mounted on the doorframe to disengage the vault's pneumatic locking system. He clasped the door handle, paused, and turned to Brooke and Flaherty. 'Few have ever been in this room. This is where I keep my personal collection,' he confided in a whisper.

When Stokes pulled the door open, a motion sensor activated the lights in the s.p.a.ce beyond.

'Come and see,' Stokes said, leading the way inside.

The tantalizing possibilities had Brooke's heart beating triple-time. She could tell Flaherty's curiosity was equally piqued.

'After you,' Flaherty said to Brooke. As she slipped past him, he paused at the threshold and gave the formidable security door closer consideration. He noted the deadbolt on the door's inside face. Giving the s.p.a.cious vault a cursory once-over, he detected no other doors or windows. The air in here was thin. One word came to mind: asphyxiation.

As she moved deeper into the vault, Brooke was rendered speechless by the incredible a.s.sortment of Mesopotamian relics Stokes had ama.s.sed. Display cases and shelves filled with jaw-dropping specimens: dozens of cuneiform tablets inscribed with the same characters she'd deciphered in the cave; ancient tools from the early Bronze Age, including an axe, chisels, hammers and knives. 'Are these reproductions?' she asked Stokes.

'All originals,' he said like a proud father. He looked back to the door. 'Will you be joining us, Agent Flaherty?'

'Just taking it all in,' Flaherty said, and made his way over in small steps. The smooth soles of his loafers caught the slick surface of a wide swath of carpet in the room's centre. A trace of chemicals wafted up into his nostrils. Cleaning solution. The area had been scrubbed very recently. Flaherty had a sneaking suspicion as to why.

'Oh wow,' Brooke muttered. She stared in wonderment at the huge monolith carved in bas-relief with two winged Mesopotamian protective spirits, or apkallu apkallu, facing one another in profile, as if courting for a dance - each half human, half lion. Raised broad wings and intricate rosettes adorning ceremonial dress depicted their divinity. 'Is this from Babylon?'

'No. That was the seal that we removed from the cave entrance.'

'Really.' She quickly tabulated that it predated Babylonian works by at least fourteen centuries. Ye t its quality was equally stunning. 'It's magnificent.'

'Indeed. Even more impressive than what came centuries after it. Just like the writing you transcribed for us - far more sophisticated than anyone ever expected.'

In the obelisk-shaped display case next to the seal, Brooke spotted a highly unusual clay tablet etched not only in writing, but schematic designs. 'This text ... these images,' she said in awe. 'Is this what I think it is?'

Stokes nodded. 'The world's oldest map. Given to me by a dear friend.'

For a long moment, Stokes stared at the artifact. More than anything, this keepsake symbolized the incredible spiritual transformation he'd undergone after the monks had found him disfigured on the roadside all those years ago.

In the sanctuary of a hilltop monastery, it had been Monsignor Ibrahim himself who'd overseen Stokes's physical and spiritual rehabilitation. The monsignor had brought Stokes to the looming mountain that marked Lilith's ancient tomb and imparted to him a haunting tale of civilization's first Apocalypse that transformed what had once been a lush paradise. By torchlight, they'd stood side by side in the cave's entry pa.s.sage as the monsignor recounted Lilith's journey, immortalized in stone. He'd shown Stokes the chamber where Lilith's victims had been buried en ma.s.se. Then he'd brought Stokes to the demon's tomb, deep inside the mountain.

'Like you, Lilith's bold venture into the unknown realm had not been in vain,' Monsignor Ibrahim had told him. 'Her predestined journey merely marked the beginning for many changes yet to come. Everything you need is here. Now it is time for your destiny to begin.'

And from that humble beginning - that tiny mustard seed - sprang Operation Genesis.

Stokes punched a code into the base of the display case, then unhinged the lid. He removed the tablet, admired it and offered it to her.

'A map for what place?' Brooke asked as she cautiously accepted the tablet.

'That, Ms Thompson, is the map to what later mythology would call Eden. A treasure map that points to the beginning of humanity and civilization. A thriving city in the northern mountains of ancient Mesopotamia. It is how we found the cave.'

Once again, Brooke was overcome by wonder.

'You can see here,' Stokes said, 'the river that once led to the Zagros Mountains. But the real clues are written here.' He indicated the wedge-shaped symbols.

The way the symbols repeated suggested to Brooke that it was a numbering system. If so, the established timeline of recorded history had again been turned upside down. The earliest known numeral system had been developed in southern Mesopotamia in 2000 BC by the Sumerians - a s.e.xagesimal system that used the number sixty as its base (with ten as a subbase). With sixty being the smallest number divisible by every factor from one to six, it could easily be separated into halves, thirds and quarters. Thus it simplified common measurements, such as time, geometric angles and geographic coordinates. The Sumerians annotated numbers one through nine with Y-shaped wedges (e.g., three: 'YYY', six: 'YYYYYY'), and tens were sideways Vs that looked like less-than signs (e.g., twenty: '<>

What appeared on this tablet looked much different - much more sophisticated than the Sumerian numbering system. 'These are numbers?' Brooke said.

'Yes. Geographic coordinates based on astrological measurements,' Stokes said. 'Ingenious for its time.'

'Is that possible, Brooke?' Flaherty asked.

She considered it, then nodded. 'The Mesopotamians were obsessed with the celestial cycles. So I'd say, yes.' But without fully transcribing and testing the number system she had to accept what Stokes was saying. 'And this was what led you to the cave?' she asked Stokes.

'Yes.'

If he'd truly been able to decipher this tablet, she thought, then why would he have commissioned her - an outsider - to a.s.sist in the excavation? It didn't add up.

Flaherty was losing his patience. 'This is all very nice, Stokes. But let's talk about the other things you found in the cave. The real reason behind your excavation. We know about the skeletons. So why did you study all their teeth?'

'Yes, the teeth,' Stokes said. He reflected for a moment to choose his starting point. He directed his response to Brooke. 'As you know, the emergence of civilization was long, uneven, violent, and marked by many false starts and setbacks. And every major turning point ... every conquest in history, was determined by nature's most potent equalizer: disease. Pestilence is the planet's survival mechanism. The means not only for maintaining equilibrium, but for genetically selecting winners and losers.'

Flaherty said, 'I thought guys like you didn't believe in evolution?'

'Creationism may make for good sermons, but it certainly doesn't make good sense or good science,' Stokes admitted. 'Ms Thompson, the story you deciphered on the wall of that cave chronicled one of the most profound events that shaped modern civilization. It told of a thriving, technologically advanced people who'd effectively been wiped out shortly after the arrival of a foreign visitor.'

'Lilith,' Brooke said.

'That's one of the names later mythology ascribes to her,' he conceded. 'Lilith was responsible for a wholesale extermination at the dawn of the earliest civilization. A theme that would play out many, many more times throughout our history.'

'But only the males died, right?' Brooke said.

Stokes raised his eyebrows. 'Every one of them. Which begged the question: how could pestilence selectively afflict only men? It seemed impossible. But the remains found in that cave substantiate the story. At that time Frank Roselli was overseeing Fort Detrick's Infectious Disease lab. His top virologists and geneticists studied specimens from the cave - traces of ancient DNA left behind from a most unusual virus. Of course, I'm not a scientist,' Stokes said, 'so the nuances are lost on me. However, I do understand the basic mechanics.' He paused to marshal his thoughts. 'The majority of conventional viruses are coded in RNA and replicate within the cytoplasm of host cells. But some viruses, like Lilith's plague, are coded in DNA and penetrate deeper into the host cell's nuclear core to replicate.'

Roselli had explained to him how the nucleus of human cells stores the entire genetic code - the genome. The genome has twenty-three chromosome pairs, twenty-two non-s.e.x chromosomes, and one pair of s.e.x chromosomes. The female s.e.x chromosome is noted as 'XX' and the male's is 'XY.' At the genetic level all humans are 99.9 per cent identical. Mutations pa.s.sed on from one generation to the next make up the remaining 0.1 per cent of the genetic code. These 'single nucleotide polymorphisms' recode one of the four nucleotides - adenine (A), cytosine (C), guanine (G) and thymine (T) - along the gene, changing an 'A' to a 'C' or a 'G' to a 'T'. And in those slight mutations, ancestry can be traced back along a 100,000-year genetic tree to one man and one woman in Africa - the genetic Adam and genetic Eve. 'Which means we're all distant cousins,' Roselli had explained. Roselli inevitably sided with science by refuting the notion of a truly common variant among any ethnic group. Yet Roselli's scientists clearly demonstrated that a high frequency of specific genetic variations were common among different ethnic groups.

Stokes's interpretation of the genetic data was simple: the Middle East was a hotbed of genetic variation, and Lilith's plague was capable of pinpointing the specific genetic sequences that accounted for it.

And Stokes was sure that Lilith's plague wasn't mere science - it was a mechanism put into play by G.o.d Himself to destroy the wicked early civilizations in the Middle East. He'd learned that from the man who'd given him the map to Eden.

'When Lilith's virus enters the host cell's nucleus, replication can only occur when the viral DNA successfully binds to a matching gene sequence found on the male Y chromosome. And we believe that that gene sequence is specific to males of distinct Arab ancestry. In the absence of this specific Y chromosome gene marker, the virus remains dormant. So a female, or a male of non-Arab descent, can carry the virus, but not manifest its symptoms.'

'Come on, Stokes. I'm no scientist, but that sounds a bit outlandish to me,' Flaherty scoffed. 'I've never heard of anything like that. There's no "Arab" gene. That's ridiculous.'

Stokes was undeterred. 'The Y chromosome makes up less than half of one per cent of the male genome. But unlike most other genes, the strands of the Y chromosome do not recombine over successive generations. Quite simply, that means the Y chromosome is transcribed almost perfectly from father to son with virtually zero mutation.'

'He's right,' Brooke said. 'It's how ancestral lineage is determined.'

This aspect of genetics, Brooke knew firsthand, had been widely adopted even by anthropologists. Human migrations out from Africa brought ancient peoples first into the Middle East. There, climate and other environmental factors caused slight adaptive mutations. The Middle East became a nexus for successive migrations pushing out across Eurasia and eventually across land bridges to the American continent and as far south as Australia (thanks to intercontinental land bridges resulting from dramatic drops in sea level brought on by the Ice Age). And every step of the human journey brought greater diversity - including slight changes both in the paternally transcribed Y chromosomes and the maternally transcribed mitochondrial DNA.

Stokes added, 'Mapping the Y chromosome is how scientists know that 16 million men living today are direct descendants of Ghengis Khan. A distinct genetic marker unites 8 per cent of all men living in the former Mongol Empire. Similarly, the skeletons we found in that cave were among the earliest ancestors of modern Arabs. When we compared their Y chromosomes to modern Middle Eastern men, the similarities were startling. So that brings us to a most compelling crossroads.' He held out his hands like a magician. 'You're a smart man, Agent Flaherty. So I'm sure you see where I'm going with this.'

Flaherty certainly understood what Stokes was implying, though he wasn't buying it. 'You're hoping to recreate Lilith's plague.'

'Bravo,' Stokes said, grinning.

'You can't be serious,' Flaherty scoffed. 'If you're bitter about losing your leg, you might want to consider psychotherapy instead.'

'I a.s.sure you this is no joke, Agent Flaherty,' Stokes said.

Brooke, too, was incredulous. 'You're saying you've created a plague that kills only males of Arab ancestry?'

'Give or take,' Stokes said.

'Give or take?' Flaherty said, horrified. 'So you're playing around with a virus that you don't even understand?'

'It's impossible to account for every mutation. We can't antic.i.p.ate every scenario,' he admitted.

'But you developed a vaccine, right?' Brooke said. 'I mean if this virus is from six thousand years ago, there's no guarantee that anyone anyone will be immune.' will be immune.'

'There is no vaccine, Ms Thompson,' Stokes said. 'And by the time one is developed, the balance of humankind will be reset, just as G.o.d intended when he sent Lilith over those mountains so long ago. Lilith had been snuffed out before her destiny was complete. We're merely giving her another chance to finish what she started. It's a perfect solution to solve the hostilities in the Middle East. No soldiers or weapons needed. We let Mother Nature do what she does best.'

'The DNA would have degraded,' Brooke said with conviction. 'The DNA in those teeth wouldn't have been any good.'

'You're missing the point, Ms Thompson. The teeth from the skeletons in the burial chamber only confirmed the genetic profiles of the plague victims. The teeth gave us a template for the Y chromosome marker. And you're absolutely correct: the viral DNA found in those specimens wasn't well preserved. However, thanks to those brazen Mesopotamians who managed to execute Lilith, some of the viral DNA had had been perfectly preserved. Let me show you.' been perfectly preserved. Let me show you.'

Brooke and Flaherty watched Stokes step over to the veil-covered display case in the room's centre. 'You see, it wasn't only Lilith's victims we discovered in that cave.' Stokes pulled the veil away, revealing the most prized item in his collection, which was locked within a rectangular gla.s.s case. 'It was Lilith herself.'

60.

Mounted atop a cylindrical gla.s.s base inside the case was a translucent sphere, flat on top and bottom, and no bigger than a medicine ball. And frozen within it was a severed human head.

'Exquisite, isn't she?' Stokes said, doting upon the severed head without utmost adoration. "'Upon her forehead was a name written, Mystery, Babylon the Great, the Mother of Harlots and the Abominations of the Earth."' He smiled. 'Revelation 17:5.'

Cold p.r.i.c.kles shot down Brooke's spine. Lilith's ancient head was both beautiful and ghastly. Wisps of golden hair intermingled with blood swirls spun through the honey-coloured sphere which resembled gla.s.s. The flesh remained intact so that even now, millennia later, the refined face seemed locked in time, a snapshot of death that bore testament to a most brutal execution. The morbid lips remained in a taunting smile. But it was the punishing, inescapable stare of the eyes that was most frightful. Like staring at Medusa, Brooke imagined herself being turned into stone.

'As you can see, she has been perfectly preserved,' Stokes said. 'After the executioners cut off her head, they immediately sealed it away, hoping that Lilith's evil would be trapped for eternity. Obviously, they were wrong, because it wasn't Lilith's soul that had been the source of her malevolence. It was her DNA. And you can see how we got to it ... where we drilled through the resin,' Stokes explained, pointing to thin bore holes that extended through the resin like invisible straws, and penetrated through the skull's soft crown. 'All we had to do was extract the dormant virions and culture them.'

'So if it's so simple, why are you so concerned about the cave?' Flaherty said.

'Come now, Agent Flaherty,' Stokes said, feigning disappointment. 'A virus in a dish is useless. For a plague to have any effect, it must be spread - widely and rapidly. It needs a catalyst.'

Then Flaherty remembered Jason saying how sick Al-Zahrani had been when they pulled him out from the cave. 'You infected Al-Zahrani, didn't you? Is he your catalyst?'

'He's infected, yes. But I certainly can't rely on him. He's only one man, after all. Let's think of him as an experiment.'

'Lilith was only one woman,' Brooke countered. 'And think of what she did.'

'This isn't 4000 BC, Ms Thompson. Things work much differently nowadays.'

'So then what is is your plan, Stokes?' Flaherty insisted. 'Sounds to me like you've got nothing to lose now. Why not just tell us what's inside that cave?' your plan, Stokes?' Flaherty insisted. 'Sounds to me like you've got nothing to lose now. Why not just tell us what's inside that cave?'

Stokes enjoyed watching Flaherty stew the possibilities. He stepped up to the display case, pressed his hand against the gla.s.s, and stared at Lilith with deep reverence. 'The inherent beauty of plague,' he cryptically replied, 'is that once it is introduced into a population, nature itself provides the most reliable and potent delivery system. It's been that way since the beginning, just as G.o.d intended. Even the mightiest empires can't stop nature.'

For a long moment, Flaherty ruminated on the phrase 'delivery system'. 'You aren't seriously considering biological warfare,' Flaherty said. 'It violates every peace treaty. The United States can't afford to-'

'No missiles will be fired, I a.s.sure you, Agent Flaherty.' Stokes's breathing was getting shallower. 'Once the infection begins, no one will be able to stop it. In under an hour this virus rips through cells ... gets into the blood, the lymph nodes, you name it. In less than two hours, it strikes the lungs and becomes pneumonic.'

'Nu-what?' Flaherty said.

'It becomes airborne. Someone can catch it just by breathing it in,' Brooke said in horror.

'Very good, Ms Thompson,' Stokes said. 'Suffice it to say, when all is said and done, an entire generation of Arabs will be wiped out ... and any threat of Islamic fanaticism right along with them. And there will be zero accountability for the United States. It will be viewed as Allah's divine retribution.'

'That's not true,' Flaherty said. 'Scientists will study the disease. They'll see that-'

'When scientists study the DNA of the virus, they'll be unable to explain its origins. I promise you that. They will rule out the possibility of any scientist being able to engineer such a complex, exotic contagion. They'll attribute the plague to a mutation bred in the backwaters of the Middle East. It's been nearly a hundred years since Spanish Flu killed upwards of 50 million people - more casualties than all the soldiers and civilians in World War I. And as far as scientists are concerned, we're long overdue for the next great pandemic. You saw how excited they were about swine flu. That was a joke compared to this. The scientific community will feel nothing but vindication.'

'Why do this?' Brooke challenged, abhorred by Stokes's indifference. 'What's the point?'

'The point? Come now, Ms Thompson,' Stokes said. 'I've fought these people for almost two decades. This is no ordinary enemy. They don't wear uniforms. They don't respect innocence. They hate civilization ... and everything we stand for. Flying planes into buildings was only the beginning for them.'

'Terrorism is a universal problem - not a Middle Eastern one,' she pleaded.

'Wars are fought one battle at a time, Ms Thompson. To spare the innocents, extreme measures are sometimes necessary. Your idealism is endearing, but fails to recognize the chilling reality we're facing. We've reached the tipping point where only one side can inevitably survive. Call it Social Darwinism.'

'You're a real nut job, Stokes,' Flaherty said. 'I'm giving you one more chance to answer my question. What's in the cave?'

'I could tell you, but that would only ruin the surprise,' Stokes replied wryly. 'Besides, it's too late for you or anyone else to do anything about it.'

'I don't have time to play games with you.' Flaherty's fuse had burned out. If there was something in the cave, Jason would need to be warned. He decided to cast diplomacy to the wind. He went for his gun. But Stokes antic.i.p.ated the move and, to Flaherty's surprise, managed to draw his own gun first. And to Flaherty's horror, the pastor levelled the Glock at Brooke's chest.

'Don't be upset, I've had lots more practice than you, Agent Flaherty,' Stokes said. Another coughing fit struck, but the gun-slinger managed to keep his aim true. He covered his mouth with the crook of his arm and when he pulled it away, blood and bile covered his jacket sleeve. 'Let's not make this messy. I told you, I'm already a dead man. Don't you see?' He held out the gory sleeve. 'I've got nothing to lose.'