The Kill Switch

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.

“FETCH 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.”