“We slowed them considerably, my general, but their scouts are less than an hour behind us. I estimate three hundred cavalry, two hundred foot soldiers, and forty 12-pound cannons.”

Roosa took this in, then rubbed his chin. “An impressive force. It seems the British have put a large bounty on our heads. Well, even if they manage to find us, the fight will be on our terms. And then, comrades, we will see how good the Engelse are at digging graves.”

After blowing and collapsing the cavern entrance, the night passed without event—as did the next day and the six days after that. Most of the Boer troops settled into their new stronghold and went about the business of making the cave system not only comfortable, but as defensible as possible, too.

Meanwhile, Roosa’s scouts used secret exits to slip from the caverns under the cover of darkness and returned with the same report: the British battalions remained in the mountains and appeared to be searching intently, but so far, they had failed to find the hidden fortress.

After a week, a lone scout returned at dawn and found the general sitting in the officers’ mess hall, a small cavern in which one of the disassembled wagons had been turned into a trestle table with benches. Roosa and De Klerk sat at one end, going over the day’s sick report under the glow of a hanging lantern.

Exhausted and disheveled, the scout stopped beside Roosa. The general stood up, called for a water skin, then forced the scout to sit down and waited as the man quenched his thirst.

“Dogs,” the scout said simply. “Bloodhounds. Coming this way.”

“Are you sure?” Roosa asked, his eyes narrowing.

“Yes, my general. I could hear them baying, not two miles away. I believe they are coming toward this position.”

“Could they be jackals instead?” De Klerk offered. “Or wild African dogs?”

“No, Doctor. My father had bloodhounds when I was a child. I know well their sound. I do not know how they would—”

“They captured three of our men,” Roosa explained, as if expecting this news. “Their scent is our scent. And concentrated as we are in this damned cave . . .” The general’s words trailed off. He looked down the length of the table at the faces of his concerned unit commanders. “Gentlemen, let us man the ramparts, such as they are. It appears the Engelse will be here for tea.”

The first hidden entrance the British found was on the cave system’s southern side, a hole disguised by a jumble of boulders.

And so it started.

De Klerk found Roosa kneeling before a sandbag barrier with one of his unit commanders, a man named Vos. Beyond the sandbags the cavern’s ceiling descended to shoulder height; at the far end, some fifty feet away, was the horizontal shaft that led to the secret exit. A dozen soldiers were stationed across the cavern floor, each one kneeling with his rifle behind a stalagmite.

As they waited, De Klerk glanced up. Finger-width fissures split the cavern’s ceiling, casting slivers of bright sunlight across the stone floor.

Roosa turned, placed an index finger to his lips, then pointed to his ear.

De Klerk nodded and said nothing. In the silence of the cavern, he strained his ears. In the distance, he could make out the faint baying of the British bloodhounds. After several minutes, the bawling fell silent.

Everyone held his breath. A soldier behind one of the forwardmost stalagmites signaled back to the barrier.

Roosa nodded. “He hears voices. Multiple men coming through the shaft. Vos, you know what to do.”

“Yes, my general.”

Vos scratched his bayonet along the rock floor, and the men stationed behind the stalagmites turned toward him. Using only hand signals, Vos gave them their orders. Though De Klerk knew what was coming, he dreaded it.

Led by the faint glow of a lantern, the first British soldier appeared in the shaft. He crawled out of the entrance, then turned left and stopped, making room for the man behind him. One by one, the British scouts crawled out of the tunnel until there were six crouched at the far end of the cavern. Silently, the enemy played their lanterns across walls and ceiling and the stalagmites across the floor.

De Klerk watched, continuing to hold his breath.

Seeming to find only an empty cavern, the trespassers clipped the lanterns to their belts, then started moving forward, their rifles at the ready.

Vos let them get within twenty feet—then, with a double tap of his bayonet on the rock floor, his men sprang the ambush and opened fire. The fusillade lasted but seconds, killing all but one of the British scouts instantly. Moaning, the surviving soldier began crawling back toward the shaft, trailing a slick of blood behind him.

De Klerk grabbed his medical bag and stood up. Roosa grasped his forearm and shook his head.

“But, General, he is—”

“I said no, Doctor. The more terrifying we make this for the Engelse, the sooner they will leave. Vos, see to it.”

At Roosa’s nod, Vos hopped over the sandbag wall, drew a knife, then walked across the cavern to the crawling soldier. He knelt down and slit the man’s throat.

Roosa turned to him. “I am sorry, Doctor. I do not enjoy ordering such a thing, but if we are to survive this, we must be brutal.”

Such butchery settled like a cold stone in De Klerk’s chest. He turned away, despairing, knowing one certainty.

Nothing goes unpunished under the eyes of the Lord.

Days passed, and still the British came. Soon the enemy had found all but one of Roosa’s secret entrances. Small but fierce battles raged at the ramparts, as Roosa had taken to calling them. It became clear the British colonel was not only willing to send his troops into Roosa’s meat grinder, but he was also willing to make terrible sacrifices—five, six, seven of his troops for one Boer wounded or killed.

De Klerk did what he could to help the injured or dying, but as the days turned into weeks, the Boer death count continued to rise—at first from British bullets, then from illness. The first ailing soldier appeared in his surgery complaining of intense stomach cramps. The medical staff treated him with herbs, but within hours the man became feverish and writhed in agony. The next day, two more men appeared with the same symptoms; then four more the day after that.

His surgery became a madhouse of incoherent screams and squirming patients. Roosa walked into the surgery on the twenty-fourth day to check on the wounded, like he did every morning. De Klerk gave the general a grim status report.

Roosa frowned as he finished. “Show me.”

Carrying a lantern, he led Roosa to a corner of the cavern where the sick men were quarantined. Together, they knelt beside the first patient who’d appeared with symptoms, a blond-haired boy named Linden. The boy flailed on the makeshift cot. His face was deathly pale. His arms had been secured to the sides of the cot with leather straps.

“Are those necessary?” Roosa asked.

“A new symptom,” De Klerk explained and reached down to show the general.

He lifted the thin cotton tunic away from the man’s torso. The patient’s belly was covered in wartlike nodules, but instead of dotting the exterior skin of his stomach, the protrusions appeared to be coming from beneath the flesh.

“My God. What is that?”

He shook his head. “I don’t know, General. Without these restraints, he would be clawing open his belly. Look here.”

Together, they leaned over the boy’s body. Using the tip of a scalpel, he pointed to one of the larger nodules, about the size of a pea. “Do you see the milky green color, just beneath the skin?”

“I see it. It’s as if something is growing inside him.”

“Not as if, General. Something is growing inside him. All of them. And whatever it is, it is doing its best to break out. They are all showing signs of it. Look here!”