He let out a sigh of relief at the sight stretching away from the piers.

  The row of barges still blockaded the river, anchored in place from earlier. Their wheelhouses stood tall, a few glowing with lights. Tires hung along their flanks.

  Monk patted Tucker’s shoulder. “Smart.”

  “We’ll see about that.”

  His internal clock counted down.

  Three minutes.

  Tucker squinted, readjusted his trajectory, and sped toward the last pier, the one closest to the nearest barge. A gangway led straight to an open hatch in the hull’s side. The ramp was wide, lined by tracks, meant for hauling in ore carts.

  He raced down the pier, hit the gangway, and shot up its length. The Rover rattled but held together long enough to reach the end and barrel into the barge’s hold.

  Two minutes . . .

  He didn’t stop. The headlights revealed giant piles of coal and metalliferous ore. He raced around the hillocks, swerving back and forth, trying to put as much of it between them and the mine.

  He finally braked hard and turned to the others. “Brace yourself. Cover your ears. Mouths open. You’re about to have the worst ride of your lives.”

  And hopefully it won’t be the death of us.

  The last minute stretched painfully. He crawled over the seatback to join Kane. He huddled with his buddy, inhaling his panted breath, feeling his warmth. A tongue licked him; a cold nose nudged his chin.

  “I know. We’re in this together.”

  To the very end.

  He checked his watch and saw the last second tick away.

  De Coster was nothing if not punctual.

  The blast sounded like the end of the world. It felt strong enough to flatten them on its own. For a beat, Tucker thought they might have escaped the worst of it—then the concussive wave hit. The barge got shoved hard, rolling sideways. Rockslides from the piles flowed toward them. Seams broke in the hull as the force crimped its length. Collisions with other barges shattered plates inward.

  The Rover tried to ride it out, sliding and skidding, but eventually it toppled end over end. Ore and coal rattled around them, over them.

  They all clung to seatbacks, to one another. Still, it was like being dumped into a paint shaker set on high. They tumbled over each other, elbowed and kicked one another. It felt like forever, but Tucker knew all too well how terror slowed time to an infinite moment.

  Finally, the world resettled around them.

  Ore still fell and shifted. Metal groaned under stress. The Rover sat ass-down in a pile of rock, sunk to its sidewalls.

  Frank climbed to the windshield that was mostly shattered and kicked it the rest of the way free. They gathered weapons and gear, then clambered out and slid down a pile of coal. It looked like the barge had landed on its side.

  “We’d better get out before it sinks,” Monk warned.

  Tucker had recovered an intact flashlight and used it to guide them. In the dark cavernous space, as they climbed over sliding rock and shale, he felt like the expedition leader of a group of cave explorers—accompanied by one hearty dog.

  They all limped and hobbled, deeply bruised and concussed, bleeding all over, but surprisingly there appeared to be no broken bones.

  Finally, Tucker reached a metal ladder that sloped horizontally to the toppled wheelhouse. They followed along its length until they could climb into the barge’s helm. All the glass had been shattered or blown out of it. They crossed as a group to get their first view of the damage.

  Frank groaned. “I don’t think we need to worry about sinking.”

  Tucker stared out across the dark jungle. It surrounded them on all sides. Barges lay crashed across the forest, looking like the wreckage of a train derailment. The entire blockade had been shoved from the river into the jungle—including their barge.

  Beyond them, past the fringe of jungle, a massive crater smoked. Fires burned at its heart, glowing through the cloud of dust. Its breadth was impossible to fully fathom, especially in the dark.

  “What do we do now?” Charlotte asked.

  Tucker shared a glance with Frank. They had already discussed the matter, with the foolish optimism that they might survive.

  And just look at us now.

  Tucker pointed upriver. “That bastard De Coster is planning something similar at his island. We overheard him. Cleaning house, he called it. At dawn. We intend to make sure it stays messy.”

  Charlotte looked aghast. “You’re going back there?”

  “It’s our best chance to reach a radio. Especially now that we know how to make it work.” He pictured Draper’s encoded thumb drive. “Plus, we might get a little payback along the way.”

  Monk nodded at this plan.

  Kane wagged a tail.

  “I’m going with you,” Charlotte said. She seemed to sense an objection building and stepped forward against it. “I have patients there. They’re still my responsibility.”

  “It’ll be a long walk back,” Frank warned.

  Charlotte’s spine straightened. “I’m not giving up on them.”

  Monk gave her a small smile. “With that attitude, can you be my doctor, too?”

  22

  April 25, 4:11 A.M. CAT

  Ituri Province, Democratic Republic of the Congo

  Gray fought the ATV up a difficult terrain of lichen-scribed boulders and mossy rocks. The vehicle’s headlights speared through the darkness under the heavy canopy. The beams bounced all about. Massive tires chewed across the landscape, riding over obstacles like a rampaging monster truck. The cabin tilted one way, then crashed down on the other, jarring everyone side to side.

  Benjie and Faraji rode in the back. Though strapped to their seats, they still braced their arms and legs in all directions, looking like a pair of squirrel monkeys struggling to keep their perches in a storm-swept tree.

  Next to Gray, Kowalski snored, competing with the rumble of the engine. His head snapped back and forth, but failed to wake him, proving there was likely nothing inside his skull that could be rattled.

  Gray had taken over the wheel two hours ago, just as the night’s storm had finally ended. Still, the humid jungle continued to weep and drip all around. He searched the eastern skies for any sign of dawn, praying for some hint that this interminable night would come to an end.

  Unfortunately, the world ahead rose in a wall of forested mountains, cliffs, and volcanic cones. Some of the peaks rose to over fifteen thousand feet. Their path climbed from the western half of the continent, topographically known as Low Africa, to the high plateaus and mountain ranges of High Africa. Splitting the two regions was the great Eastern African Rift. It stretched four thousand miles long, cracking down its length into many smaller pieces. According to the topo map, directly ahead of them was the most inhospitable section of all, called the Albertine Rift.

  The blue line that Gray had drawn on the topo map headed straight into the heart of that broken landscape, where the Somali tectonic plate shoved high, forming an impenetrable barrier of sheer cliffs and jagged mountains.

  As they climbed toward it, Gray hoped that the forest would thin, but instead it only grew taller and thicker, as if the jungle were trying to push those highlands back down by the sheer weight of the vegetation.

  The trunks of palms and red cedars grew to gargantuan sizes. Ropy lianas netted them all together, while stands of bamboo formed impenetrable barriers that had to be skirted around. The entire landscape—shrouded with moss, entangled with vines, and festooned with giant ferns—looked prehistoric, like some Jurassic holdover.

  The jungle tried to push into the cabin through the missing windshield. It smelled of a rotting sweetness. Leaves slapped at them. Mosquitoes and black flies swarmed inside, plaguing them with stings and bites. The only reprieve came when they slowed enough to allow the diesel fumes from the ATV’s exhaust snorkel to drive off the haranguing hordes. But as soon as their vehicle started moving again, the clouds would swamp back inside.

  But such tiny nuisances were the least of the threats. Gray constantly searched the jungles for any bigger dangers. Back a mile ago, a herd of wild hogs, curl-tusked beasts, had trampled around their ATV, skirting them like a boulder in a river. But the hogs had moved onward, ignoring them, leaving them unmolested.

  Gray found himself holding his breath for long stretches. Tension tightened the muscles between his shoulder blades. He felt exposed with the window missing. They had not been attacked in hours, so he expected another assault at any moment. He glanced all around as he forced the ATV up the next steep incline.

  When he reached the top, the terrain finally leveled out for a stretch. He followed a swollen stream, where a recent flash flood had cleared much of the undergrowth and brush from along its banks. Able to travel faster, he felt more hopeful.

  Still, the dark jungle around them remained daunting. The Ituri rain forest covered over twenty-five thousand square miles. A fifth of it was preserved and managed under a conservancy, but the rest was wild and untamed. Especially this remote eastern corner, where the land was a confounding maze, all buried under thick forest.

  Anything could be hidden here.

  The same worry must have drawn Benjie to release his vicelike hold on his armrests and lean forward. “I’ve been thinking about the source of this virus,” he said.

  Gray looked back to him. “What about it?”

  “If it truly lies somewhere ahead of us, it must have remained dormant for ages, possibly for millennia.”

  “At least going back to the time of Prester John and his lost kingdom,” Gray agreed.

  “Exactly. But what set this virus off now? After so long? Something had to trigger it. That’s what I’ve been struggling with.”

  Gray frowned at the biologist. “I thought we believed it was the recent flooding, that it flushed that virus loose into the greater world.”

  “I have no doubt that the heavy monsoons exacerbated the spread of the virus. But I think its initial release predated the storms. By several months. Probably longer. Especially after what we’ve seen.”

  “How do you mean?”

  “I keep thinking about those jackals. The rains and flooding must have forced them to migrate from their normal territory. Wherever the pack had come from, the virus must have been smoldering for at least a year in order to generate those biological changes.”

  Gray considered this. According to Benjie’s earlier discourse, a jackal’s gestation period, followed by the time it took for a pup to grow to maturity, spanned nearly a year.

  Benjie continued, “But if that jackal pack had always lived within the scope of the virus, I would’ve expected more divergence from their normal appearance, especially after so many generations of exposure. They wouldn’t be just bigger versions of themselves.”

  “So, you think the animals were exposed within the past year, causing them to be only mildly altered. Then the floods drove them farther afield.”

  He nodded. “If I had to guess, I would say the virus began its spread abruptly, but it only reached a limited area at first, effecting local species. After that, it slowly spread outward. Passing from species to species.”

  “Until the storms came.”

  Benjie nodded. “The flooding would’ve triggered a mass migration, a huge shift in the environment, leading the virus to eventually spill over into the human population.”

  “Which we know was a recent event. But you’re thinking the virus was brewing out there for far longer.”

  “I do. Which worries me.”

  “Why?”

  “We’ve been focused on trying to figure out where the virus originally came from, but I think it’s equally important to know what triggered its initial spread, after millennia of being dormant.”

  Gray suspected he was right. “Do you have any thoughts on that?”

  “Maybe . . .”

  Gray heard the hesitancy in the biologist’s voice. The young man was clearly gifted, able to work out puzzles, maybe as well as Gray could. Benjie was a kindred spirit in this regard.

  “What are you thinking?” Gray pressed him.

  Benjie stared off into the jungle. “Right now, we seem to be the main target of the virus. It makes us dull and unresponsive, while ramping up the environment into a more hostile state. Though, perhaps I may be placing too much intelligence and forethought into a virus. Instead, all of this might simply be due to man’s encroachment into the virus’s normal biosphere. Through roads, construction, deforestation.”

  Gray pointed ahead. “On the map, it shows a major mining enterprise—Kilo-Moto—at the northeast corner of the DRC, right on the border. It’s only a couple hundred miles from where we are now. I read that its operations have been slowly spreading deeper into the jungle.”

  The mine had also caught Gray’s attention for another reason. It was a major gold-mining operation, established when nuggets were discovered along the Ituri River in 1903. Considering Gray’s team was hunting for a mythic kingdom tied to legends of King Solomon’s famous gold mine, he thought the current operation might further support an historical basis for a lost mine being established in this region.

  Benjie stared off in the direction where Gray had pointed. “Maybe the uptick in local mining upset the virus’s natural environment, allowing it to break loose. But I don’t know.” He rubbed at the peach-fuzz scruff of beard over his jawline. “I’m not buying it. I still think we’re missing a main catalyst. Something more dramatic that immediately impacted the environment and loosed the virus on the world.”

  “Like what?”

  Benjie shrugged. “I have no idea. But if there’s an answer, it lies somewhere ahead of us.”

  Gray returned his full attention forward.

  Then we’d better find it.

  5:02 A.M.

  Forty minutes later, Gray rubbed the sweat from his eyes. The stream they had been following had grown steamy, heated to a near boil. It raised the humidity in the area and added a sulfurous stink to the air.

  He was relieved when the waterway finally vanished underground. As he rode past the hot spring, its presence served as reminder that this entire rift area was geologically active, prone to frequent earthquakes, and home to volcanoes both dormant and active.

  Unfortunately, while he was happy to escape the spring’s sulfurous heat, the jungle quickly closed in on both sides. To make matters worse, the terrain climbed yet again.

  Gray slowed the ATV. Through breaks in the canopy—and with the clouds momentarily thinning to allow the moon to shine—he spotted the dark silhouette of peaks and cliffs cutting the sky in half ahead. He tried to judge the distance.

  We must be close.

  Gray drew to a stop and nudged Kowalski, who still snored next to him. When there was no response, he tried once more, with more fervor. After still nothing, he tried to elbow him in the ribs—only to have his arm caught in a large mitt.

  “Hit me again,” Kowalski said, shoving Gray away, “and I’ll return the favor—only a lot harder.”

  Gray ignored the threat. “Just grab my pack. It’s time we checked in. Maybe Painter and Kat are having better luck than us.”

  Kowalski grumbled, retrieved the sat-phone from his bag, and resecured its battery. He handed it over to Gray. “I’d bet my left nut that Sigma’s as lost as we are.”

  Gray placed more confidence in the others. He called up Sigma command. The connection was immediately picked up. Both Painter and Kat were on the line, clearly waiting for this call.

  “We reached the highlands,” Gray reported in. “Any luck at your end?”

  “I’ll let Kat answer that,” Painter said.

  Gray heard the strain in her voice when she came on the line. “We weren’t able to pinpoint any single site with certainty,” she admitted. “Then again, the photo was taken over a century ago. Between erosion and landslides, the topography has likely changed significantly.”

  Gray closed his eyes, his heart sinking in his chest.

  Kat continued, “Jason and I were able to do some extrapolations. We searched for those areas that most closely matched the silhouette in the photo. We came up with eighteen possible sites. I’m transmitting them to you now.”

  Cradling the phone at his ear, Gray pulled out his digital pad and brought up the topo map. As he watched, tiny blue squares appeared on the screen, dotting the highlands.

  So many . . .

  “You weren’t able to narrow them any further?” Gray asked.

  “We’ve been a tad busy,” she said sharply.

  He could guess the source of her irritability and tension. “Any word on Monk and the others?”

  “Not yet,” she answered curtly.

  Painter cut in. “Between the chaos spreading with the virus and a less-than-efficient chain of command in the DRC, it’s been difficult to get cooperation. Plus, the entire area is being pounded by thunderstorms. We’re hoping by dawn to be able to mount a more determined effort.”

  Gray could only imagine Kat’s fear. “I have no doubt Monk will hold his own until then.”

  “He damned well better,” she answered.

  Gray studied the spread of blue dots on his map. Despite his own worries for his best friend, he set aside those fears, compartmentalizing them away. There was nothing he could do out here, and he had his own daunting task ahead.

  Fearing to keep this connection open any longer, he signed off. He gave the others a brief account of the call. He passed the topo map around to show them the challenge ahead.

  Kowalski returned the pad to him with a scowl. “Doesn’t give us much to go on.”

  “No, it doesn’t.”