Anya looked stunned. “I didn’t think about that.”

Tucker smiled. “All part of the service, ma’am.” He prepared to lower himself down, then stopped. “Wait, I just realized I can’t get any GPS lock underground. I’m going to have to go old school. Christopher, lend me your walking stick.”

Their guide understood. “To act as a yardstick. Very clever.”

“Give me thirty minutes. Unless there’s a cave-in.”

“If that happens,” Christopher said, clapping him on the shoulder, “I’ll alert the proper authorities to recover your body.”

“And Kane’s, too. I want him buried with me.”

“Of course.”

Anya frowned at them. “That’s not funny.”

They both turned to her. Neither of them was trying to be humorous.

That realization made her go pale.

Twisting around, Tucker lowered himself over the edge and dropped below. As his boots hit the ground, he crouched, turned on his flashlight, then ducked into the side tunnel. As he crawled on his hands and knees, he slid the walking stick end to end and counted as he went, mapping his route on a pocket notebook.

Occasionally, his back scraped the ceiling, causing miniavalanches of sand. In the confined quiet of the tunnel, the cascade echoed like hail peppering a sidewalk. He reached the intersection of tunnels and followed Kane’s path to the left. Working diligently, it still took him an additional five minutes to map his way down to the cavern.

Kane heard him coming, trotted over, and licked his face.

“Good boy, good job!”

Tucker shined his flashlight around the room. Clearly the Boer troops must have spent a lot of time down here. The surrounding sandstone walls had been carved into benches and rudimentary tables, along with dozens of pigeonhole shelves. Ghosts of men materialized in his mind’s eye: laughing, lounging, eating, all during one of the bloodiest and most obscure wars in history.

After jotting down the final measurements, Tucker lifted the page of his notebook toward Kane’s camera and passed on a thumbs-up to the others above. He wanted a visual record of his calculations, of the coordinates of Grietje’s Well, in case anything happened to him.

Satisfied, with his knowledge secure, he knelt and dipped his fingers into the water. It was cold and smelled fresh.

How long had people been using this spring?

He pictured ancient tribesmen coming here, seeking a respite from heat and thirst.

He decided to do the same. It felt like an oasis—not just from the blazing African sun, but from the pressures of his mission. The events of the past days came rushing back to him, a tumult of escapes, firefights, and death. At the moment, it all seemed surreal.

And now I am here, huddled in the bowels of a century-old Boer fort?

All because of a plant species almost as old as the earth itself.

He looked at Kane. “Can’t say our lives are boring, can we?”

Confirming this, a sharp crack exploded, echoing down to the cave.

Tucker’s first thought was rifle fire.

Another lion attack.

Then a deeper grumble came, a complaint of rock and sand.

He knew the truth.

Not a gunshot.

A crack of breaking timber.

A cave-in was starting.

30

March 19, 5:28 P.M.

Outside of Springbok, South Africa

Tucker shoved Kane into the tunnel as the rumbling in the earth grew louder, sounding like the approach of a locomotive.

“ESCAPE! OUTSIDE!”

Kane obeyed the frantic, breathless command and dove out of the cave. The shepherd could move faster, so had a better chance of surviving.

No sense both of them dying.

Tucker did his best to follow. He abandoned his flashlight, freeing one hand. But he dared not discard Christopher’s walking stick. He had failed to measure it before jumping down here. To do his final calculations of the spring’s coordinates, he needed the stick’s exact length.

Ahead, the LED lamp from Kane’s camera bobbled deeper down the tunnel, outdistancing him as he scrambled on his hands and knees. Skin ripped from his knuckles as he clenched the walking stick. His knees pounded across rough rocks and hard stone.

He’d never make it.

He was right.

A grinding roar erupted ahead, accompanied a moment later by a thick rolling wash of dust and fine sand through the air.

The tunnel had collapsed.

Through the silt cloud, Kane’s lamp continued to glow, jostling, but not seeming to move forward any longer. Coughing on the dust, Tucker hurried to his partner’s side.

Past Kane, a wall of sand, rock, and pieces of broken timber blocked the tunnel. There was no way past. The shepherd clawed and dug at the obstruction.

Tucker pushed next to him. With his free hand against the wall, he felt the vibration of the earth. Like a chain of dominoes, more collapses were imminent. With his palm on the wall, his fingertips discovered a corner at the edge of the obstruction.

“HOLD,” he ordered Kane.

As the shepherd settled back, Tucker twisted the dog’s vest camera to shine the light on his hand, still pressed against the wall. He glanced over his shoulder, then back to his fingers, regaining his bearings.

He realized they had reached the intersection of the two tunnels.

The collapse had occurred in the passageway to the right, the one leading from the entry shaft to here. What blocked them was the flood of sand and rock that had washed into this intersection by the cave-in. That meant there was no way to get back out the way they’d come in. But with some luck, they might be able to dig through this loose debris to reach the tunnel on the far side. Of course, there was no guarantee that such a path would lead to freedom, but they had no other choice.

“DIG,” he ordered Kane.

Shoulder to shoulder, they set to work. Kane kicked rocks and paw-fulls of sand between his hind legs. Tucker grabbed splintery shards of wood and tossed them back. They slowly but relentlessly burrowed and cleared out the debris.

With raw fingers, Tucker rolled away a large chunk of sandstone down the slope of debris. He reached into the new gap and found—nothing. He whooped and scrambled faster. He soon had enough of a path for the two of them to belly-crawl through the wash of debris and into the far tunnel.

Kane shook sand from his coat.

Crouched on his hands and knees, Tucker did the same—though his shaking was a combination of relief and residual terror.

“SCOUT AHEAD,” he whispered.

Together, they set out into the unknown maze of subterranean tunnels of the old Boer fort—and it was a labyrinth. Passageways and blind chambers met them at every turn. Tucker paused frequently to run his fingertips along the roofs or to shine Kane’s lamp up.

Distant booms and rumbles marked additional cave-ins.

At last, he found himself standing in a square space about the size of a one-car garage. From the carved shelves and the decayed remains of smashed wooden crates, it appeared to be an old cellar. More tunnels led out from this central larder.

He bent down and turned Kane’s lamp up.

He sighed in relief.

The low ceiling was held up with wooden planks.

As he straightened, Kane growled, a sharp note of fury—then bolted for the nest of crates. He shoved his nose there, then came backpedaling, shaking his head violently. After a few seconds, he trotted back to Tucker’s side, something draped from his jaws.

Kane dropped it at his feet.

It was a three-foot black snake with a triangular head that hinted at its venomous nature.

Only now, past the hammering of his heart, did he hear a low and continuous hissing. As his eyes adjusted, he saw shreds of shadow slithering over the floor, wary of the light. From the other tunnels, more snakes spilled into the chamber. The trembling of the earth was stirring them out of their nests, pushing them upward.