Kill Switch (9780062135285) (34 page)

Behind him he heard a
whomp,
followed by a second, sharper
boom
.

He kept sprinting as a string of firecrackers—­the cache of artillery shells—­began detonating.

Head down, legs pumping, he kept going.

Don't look back! Run!

The pressure wave hit him and sent him flying.

2:39
A.M.

Tucker landed in a heap, blinked hard, and spat out a mouthful of dirt, swearing under his breath. He had survived, gotten the others out safely—­but still failed.

Kharzin had a sample of LUCA.

The rumble of engines echoed from the other canyon. The Russians were preparing to leave.

Tucker looked around. Behind him, the cliff face that he just jumped through showed little sign of damage, save for the gout of smoke and dust gushing through his exit hole. But he knew inside, that tiny microcosm of the primordial world was gone, incinerated.

But it was too little, too late.

He pictured Kharzin in one of those SUVs, clutching a buttery-­white bulb.

Was there still time to catch him—­and, more important, catch him by surprise?

Tucker would never make it out and around to the other canyon, and even if he did, he'd likely just be run over. Instead, he turned and headed back the way he had come, checking his pockets as he ran. He'd lost his rifle, so he would have to improvise. He sprinted, passing through the surge of smoke, and skidded to a stop beside the boulder steps that led up to the plateau. He scrambled like a monkey with his tail on fire. When he reached the top, he paused for a breath, picturing what lay below. He was now standing
atop
the cavern inside. If the blast there had weakened the structure, he might drop straight through.

Might, maybe, if . . . the hell with it.

He charged across the plateau toward the opposite canyon. As he neared the edge of the cliff, the rumble of the trucks ratcheted to twin roars. Tucker slid to a stop and looked down to see both of Kharzin's SUVs racing along the canyon floor, their headlights bouncing over the rock walls.

Tucker started running parallel to them, balanced on the cliff's edge: one eye on his footing, one eye on the SUVs. Somewhere directly ahead of him was the end of the cliff, the section shaped like a pig's snout. He ignored the voice in his head yelling for him to stop.

Instead, he ran faster and yanked out the two grenades he had stolen from the soldier he had shot. As he reached the cliff's edge, he dropped to his butt and began sliding down the steep slope of the snout. To his right, out of the corner of his eye, the first SUV raced past him. Skidding along, he pulled the pin with his teeth, but he kept the spoon pressed tightly.

Then he reached the blunted end of the snout and went airborne. The drop was only ten feet, but he was flying. He hit the ground hard and shoulder-­rolled, hugging his limbs tightly, clutching the grenades to his belly. As his momentum bled away, he skidded to a stop and rose to his knees. He let the grenade's spoon pop and hurled it after the lead SUV as it swept past him.

Behind him, an engine roared. Headlights flashed over him. He spun to find the second SUV barreling straight at him. He dove right and rolled out of its way, barely making it. Flipping to his back, he pulled the pin on the second grenade and lifted his arm to throw—­

Whomp.

The first grenade exploded, fouling his aim as he let loose with the second. The black chunk of armament bounced harmlessly past the second SUVs back bumper and rolled into the scrub. Escaping damage, the truck sped away, dropping down the ravine that led up here—­and was gone.

Whomp.

Bushes blasted away, amid a choke of rock dust.

All that wasted fury . . .

Cursing, Tucker turned to the first SUV. Its right side was on fire, flames licking inside. From the cabin came screaming.

He ran toward the SUV, not knowing if Kharzin was in this vehicle or the one that got away. There was only way to know for sure. He ran to the far side of the burning SUV, where the flames were less intense, and yanked open the passenger door. Heat washed over him, accompanied by a few licks of fire that he dodged.

The driver lay slumped at the wheel, his back burning, his skin blackening and oozing. But his uniform marked him as a major, not a general. Same was true of the passenger. The second man had caught shrapnel in the chest and the side of his face. The man groaned and grabbed Tucker's wrist. His head turned, revealing a flayed cheek and an eye scorched black. His mouth opened, but only guttural sounds came out.

Tucker twisted his wrist, trying to free it from the man's viselike grip.

“
Nyet,
” the man rasped finally. “
Nyet
.”

His other hand rose—­clutching a grenade. He threw it over his shoulder into the backseat and held fast to Tucker, trapping him with a strength born of vengeance and pain.

Not hesitating, Tucker swung his fist and smashed it into the guy's face. As the man's head snapped back, he finally broke free and ran. He'd only taken a handful of steps when a sledgehammer struck him across the back.

Everything immediately went dark.

41

March 22, 7:57
A.M.

Groot Karas Mountains, Namibia

The world returned in fits and starts, fluttering pieces that lacked substance: a shadowy glimpse of a face, whispers near his ear, something cold poured through his lips.

Then something real: the lap of a warm tongue along his cheek.

I know that . . .

He forced his eyes to open, to focus, blinking several times, and found himself staring at a brown-­black nose, whiskers, and the darkest amber eyes. The wet nose nudged him a few times.

He groaned.

“Sleeping Beauty awakes.” That had to be Bukolov.

Tucker sensed he was somehow moving, bumping along, but his legs were immobile.

“Lie still, Mister Tucker,” Christopher said as he hauled Tucker along in a makeshift travois, the sled made of branches and climbing rope.

Coming slowly alert, Tucker took in his surroundings. The sun was up, low in the sky, likely early morning from the residual chill. They were moving through forests that were too tall and thick for the upper highlands of the Groot Karas.

Nearing the foothills . . .

He finally pushed up on an elbow, causing the world to spin for a moment, then steady again. He spent another minute just breathing to clear the cobwebs from his head.

Kane sidled over, his tail wagging, a prance to his gait.

“Yeah, I'm happy to be alive, too.” Tucker called to Christopher, “I think you've played oxen long enough, my friend. I can walk.”

Christopher lowered the sled. “Are you sure?”

“I'll let you know when I'm back up on my legs.” He reached out an arm. “Help me up.”

They lifted him to his feet and held him steady as he regained his balance.

He looked around. “Where are we?”

“About a five-­hour walk from the cavern,” said Christopher.

Bukolov explained, “When we heard the grenades, we came as fast as we could and found you near the destroyed vehicle.”

“I told you both to keep going,” Tucker said. “Not to turn back, no matter what.”

“I don't remember him saying that, do you, Christopher?”

“I'm sure I would have remembered that, Doctor Bukolov.”

“Fine.” He turned to Bukolov, his chest tightening as he relived the events of last night fully in his head. “Doc, where are your LUCA samples?”

“Right here in my satchel with the lichen—­”

“Count them.”

Frowning, Bukolov knelt down, opened his kit, and began sorting through it. “This isn't right. One is missing.”

“What about the lichen samples?”

He counted again, nodding with relief. “All here. But what about the missing bulb?”

“Anya must have snatched it during the tumult of her escape. Kharzin has it now.”

Her father . . .

“That is not good,” Bukolov moaned. “With the resources at his disposal, he could wreak havoc.”

“But he doesn't have the lichen. Which means he doesn't have the kill switch for controlling it.”

Tucker pictured the burned bulbs and stalks that came in contact with the phosphorescent growth.

“And we do . . . or might.” Bukolov looked determined. “I'll have to reach a lab where I can analyze the lichen, run challenge studies with the LUCA organism. Find out which component or chemical is toxic to our ancient invasive predator.”

“Then that's what we'll do. We need that kill switch.”

And soon.

10:02
A.M.

Two hours after they ditched the travois and slowly worked their way east toward their old campsite in the foothills, Kane came sprinting back from a scouting roam. He sat down in front of Tucker, stared up at him, then swung his nose toward the east.

“Something ahead,” Tucker said.

Bukolov dropped back a step. “Bandits? Guerrillas?”

“Maybe. Christopher, you take the doctor into cover. Kane and I will go have a look.”

Tucker followed the shepherd east down the next ravine to a string of low hills. He climbed one to gain a good vantage point and dropped to his belly.

Below and two hundred yards away, a lone SUV trundled across a salt flat, heading in their direction. He lifted his binoculars, but with the sun in his face, it took him a few moments to adjust. Finally, he was able focus through the vehicle's windshield.

He smiled when he recognized the driver.

It was the group's regular chauffeur.

Paul Nkomo.

“F
ETCH EVERYONE
,” he instructed Kane.

As the shepherd raced back to the others, Tucker stood up and waved his arms over his head. The SUV stopped, and Paul leaned out the window. A glint of sunlight on glass told him Paul was peering back at him with binoculars.

Then a thin arm returned the wave.

Christopher joined Tucker a few moments later. He frowned down at the slow approach of his younger brother. “Little Paul. He was supposed to meet us at the campsite, but as usual, he didn't listen and kept heading this way. Always the impetuous one. Always getting himself into trouble.”

Tucker glanced over at his bruised, sprained, and lacerated friend. “Yeah, right,” he said sarcastically, “
he's
the troublemaker of the family.”

8:42
P.M.

With the assistance of their regular chauffeur, Tucker and the others reached the Spitskop Game Park shortly after nightfall, where staff awaited them with food, drink, and first aid, including veterinary care.

A man in a clean smock who told wild stories of life as an African vet cleaned Kane's wounds, listened to his heart and lungs, and palpated the area of his ribs that had taken Anya's bullet.
Nothing broken just a deep bruise
was his verdict. Only after that did Tucker allow a nurse to stitch the four-­inch-­long gouge in his thigh.

Hours later, Tucker found himself visiting Bukolov in a private room. The doctor had his own unique needs that went beyond food and medicine. He had borrowed a dissecting microscope and some lab equipment from a group of scientists doing research locally. Though he and the others were due to depart for the United States at midnight, Bukolov had wanted to get a jump on his investigation into a potential kill switch for LUCA.

Tucker didn't blame him. After his brief encounter with General Kharzin, he knew they dared not waste a moment. He knew Kharzin would be working just as quickly to weaponize his prize.

“How are things going?” he asked Bukolov.

The man sat hunched over the dissecting microscope. A specimen of LUCA, sliced in half, lay on the tray under the lenses. “Come see this.”

Bukolov scooted back to make room for Tucker to use the eyepiece.

He found himself staring at the edge of the specimen. The outer surfaces were peeling away like the layers of an onion, the tissue pinpricked with tiny holes.

“That is a sample of dying LUCA taken from the cave,” Bukolov said.

Tucker pictured that glowing primordial garden.

“I'm fairly certain what you're looking at here is a chemical burn, something given off by the lichen.
What
that chemical is I do not know, but I have a hypothesis, which I'll get to in a moment. But first let me tell you about this mysterious glowing lichen.” Bukolov looked at him. “Are you familiar with lichens?”

“Considering I thought it was moss . . .”

“Oh, my dear boy, no. Lichens are much more ancient and strange. They're actually made up of
two
organisms living in a symbiotic relationship. One is a fungus. The other is something that photosynthesizes.”

“Like plants.”

“Yes, but in the case of lichens, it's either an algae or cyanobacteria that pairs up with the fungus.” He slid over a petri dish of the glowing organism. “In this particular case, it's a
cyanobacteria
. Cyanobacteria are three to four billion years old, same as LUCA. Both inhabitants of the strange and hostile Archean eon. And likely competitors for the meager resources of that time.”

“Competitors?”

Bukolov slid the lichen sample and slices of bulbs resting in another petri dish next to each other. “You see, during that Archean eon, true land plants were yet to come. These two were the earliest precursors.”

He tapped the lichen. “Cyanobacteria gave rise to modern chloroplasts—­the engines of photosynthesis—­found in today's plants.”

He shifted the sample of LUCA. “And here we have the earlier common ancestor, the stem cells of the flora world, if you will.”

Tucker pictured the microcosm of that ancient world found in the cave. “And the two were in competition?”

“Most definitely. In that harsh primordial time, it was a winner-­takes-­all world. And I believe it was that
war
that was the evolutionary drive for the rise of today's modern plants.”

“And what we saw in the cave?”

“A snapshot of that ancient battle. But as in all wars, often common ground is found, cooperation necessary for short periods of time. What we witnessed below was an uneasy détente, two enemies helping each other survive in such strict isolation. Both needed the other to live.”

“Why do you think that?”

“During my studies here, I found
healthy
LUCA bulbs with dead lichen melting deep inside, being consumed. I believe
living
lichen can kill LUCA and use it as some fertilizer source. While at the same time, as the lichen die and flake from the roof and walls, it feeds the LUCA below, raining down, landing on those broad mushroomlike growths.”

“You're saying they were feeding off each other.”

“That. And I'm sure the constant flow of water through the chamber brought a thin and steady flow of nutrients and biomatter to them as well. I also think their relationship was more nuanced, that they helped each other out in other ways. Perhaps the lichen's bioluminescence served some beneficial advantage to the LUCA, while the sulfur-­rich gas—­that stink we smelled down there—­given off by the germinating bulbs helped the lichen in some manner. I don't know if we'll ever understand it fully. That unique relationship was formed as much by geology as it was biology.”

“And how does that help us find the kill switch?”

Bukolov held up a finger. “First, we know that the
living
lichen can kill LUCA, but not
dead
lichen. So that knowledge alone will help me narrow my search for the chemical kill switch.”

He raised a second finger. “Two, we know who won that ancient battle. LUCA was vanquished, all but this small isolated garden, leaving behind only its genetic legacy in the form of modern plants. But cyanobacteria survive today, going by their more common name: blue-­green algae. Because of their versatility, you can find cyanobacteria in every aquatic and terrestrial location on the planet, from the coldest tundra to the hottest volcanic vent, from freshwater ponds to sun-­blasted desert rock. They are masters of disguise, merging with other organisms, like with the lichen here, but also with other plants, sponges, and bacteria. They can even be found growing in the fur of sloths.”

“It almost sounds like your description of LUCA from before. An organism with limitless potential.”

“Exactly!” Bukolov stared over at Tucker. “That's because cyanobacteria are the closest living organisms to LUCA today. But from my studies—­on a purely genetic scale—­LUCA is a thousandfold more efficient, aggressive, and tough. Released today, unchecked and untamed, LUCA would wreak untold ecological havoc across every terrain on Earth, both land and sea.”

“But, Doc, it
was
defeated in the past. Like you said, it didn't survive.”

“And that's the second clue to discovering the kill switch:
Why didn't LUCA survive, while cyanobacteria did?
”

Tucker had to say he was impressed with how much Doctor Bukolov had learned in such a short time. He could only imagine what he could accomplish with Sigma's laboratory resources in the States.

“I have much to ponder,” Bukolov said.

Tucker's satellite phone buzzed in his pocket. “Then I'll leave you to it.”

He headed out of the room and answered the call.

“How are you all doing out there?” Harper asked as the line connected. He had already debriefed her about the past day's successes and failures. “Will you be ready to go at midnight?”

“More than ready.”

“I talked to the military biologists over at Fort Detrick, and they wanted to know if Doctor Bukolov had any estimate on how long it would take Kharzin to weaponize his sample of LUCA.”

“That's just it. According to Bukolov, it would take very little engineering. It's a ready-­made weapon. All that he really needs to figure out is the method of delivery and dispersal.”

“And how long would it take General Kharzin to do that? It seems Bukolov knows this man and his resources fairly well.”

“No more than a week.”

“Not much time,” she said dourly. “And is Bukolov any further along with the kill switch?”

“Some progress, but any real answers will have to be worked out back in the States.”

“Then I have one last question. From Bukolov's assessment of the general's personality, would Kharzin unleash this bioweapon without that kill switch.”

“In other words, how much of a madman is he?”

“That's about it.”

“I don't have to ask Bukolov.” Tucker reviewed his dealings with Kharzin from Vladivostok to now. “He'll test it. And he'll do it soon.”