It was a small clay bowl that saved Dirk’s life.
He had left the float bag in place while he swam into the cave to retrieve Summer’s underwater camera. He found it next to the fire pit. As he reached to grab it, his hand dipped into the silt and brushed something smooth and round. Finding a grip, he pulled free a small pottery bowl with the faint image of a snake carved on the bottom.
Slipping the bowl into a pocket on his BC, he probed for more artifacts. He felt nothing but ooze. As a grinding rumble sounded overhead, he glanced toward the cave entrance in time to see its blue glow turn dark. Seconds later, he was enveloped in a cloud of murky water.
Dirk swam blindly to the entrance, feeling his way along the cave floor until colliding with a large rock that blocked his way. As the sediment began to settle, he saw a gap of light to one side. He moved to the opening as a second rumble sounded above him. He considered darting out but hesitated when he heard a large splash. Shining his light through the opening, he saw a cascade of rocks tumble onto the ledge before a new cloud of sediment snuffed out his view.
Dirk could feel the vibration through the rocks as they piled up. It was several seconds before the slide subsided. The rocks from the ridge had knocked loose a large subsurface outcropping, which dumped even more tons of debris onto the ledge. Buried under the avalanche, the cave’s tiny entrance was completely sealed.
Dirk backed away from the entrance and examined his air pressure gauge. The needle hovered just above the red low-air warning marker. He had five, maybe ten minutes of air left.
Trapped in an underwater cave with little air, it would have been a perfect time to panic. But Dirk suppressed any such fears and took a calm breath of air, assessing the situation.
His initial urge was to attack the rock pile and try to dig free. Perhaps Summer was already preparing to dig on the other side. But logic told him he would never make it. The thundering avalanche had dropped so much rock, he would exhaust his air supply long before tunneling out.
If that was his only option, so be it. Then he looked up. The cave ceiling rose in twin fissures that angled up nearly twenty feet. He decided to take a quick look.
Gripping his flashlight, he kicked upward, following the first fissure until it converged in a narrow, jagged point. He backtracked and swam up the second fissure, finding a similar cathedral peak. The walls and fissure appeared to be solid rock. He turned and descended, almost missing it. But out of the corner of his eye, he caught a tiny speck of light.
Swimming closer, he found its source, a small pinhole in the rock wall leading to the lake. He pulled out a Randall dive knife strapped to his thigh and poked the tip into the hole. The light expanded as a small chunk of rock flaked away. Dirk began jamming the knife into the hole, gradually increasing its diameter to the size of a softball.
It was a way out, he knew, but he faced the same dilemma. Could he excavate a large enough hole before his air ran out? He had already used three minutes’ worth. With limited time, the knife alone wouldn’t do the job. He’d need more leverage.
He swam down to the cave floor, approached the ore pile, and searched for a stone he could use as a hammer. He spotted one with a blunt side and plucked it from the pile. Beneath it was a green rock with a near-perfect wedge shape. Intrigued by the shape, he picked it up, then realized that it wasn’t a rock. It was too heavy for its size and had a perfectly round hole in its underside.
Dirk held it close to his mask and recognized it as an oxidized copper ax head used to chip ore from the cave walls. The Aztec had been skilled stone carvers, he recalled, crafting statues and temples from the local basalt. Neighboring Mixtec craftsmen in Oaxaca, advanced in the skill of metallurgy, would have traded copper-based tools with the Aztecs. Though the wood handle had disintegrated, the copper head of the ancient ax was still solid.
He quickly swam back to the fissure and put both objects to work. Placing the business end of the ax head next to the opening, he struck the blunt side with the round stone. Muffled by the water, the impact registered as a loud click. Dirk struck it again and a chunk of rock broke away from the opening. The ancient Mixtec metallurgists had mixed tin with the copper when they forged the ax, producing a hard bronze-like metal that was surprisingly effective at cutting stone.
Feeling resistance from the air drawn through his regulator, he began pounding madly at the copper chisel. He didn’t have to check his pressure gauge to know he was drawing on his final air reserves. Striking hard caused the rock wall to stubbornly break away in fist-sized pieces. Pulling the loose rock away revealed a hole that was a foot in diameter.
Dirk took a breath and nothing came through the regulator. His tank was completely dry.
Without hesitating, he pounded the chisel as hard as he could. More fragments fell away, but the opening was still too small. His lungs tightened as a pounding in his head mimicked his banging on the rock. Through the vibrating ax head, he could feel a slight give in the rock wall. But the small, ancient ax felt like a ball-peen hammer tapping against the Hoover Dam.
He dismissed the fear of drowning, slipped off his BC, and removed the steel air tank. Grasping it by the neck, he smashed the bottom against the rock. The wall vibrated but nothing more. He smashed it again. And again. The tank collided with a clatter as Dirk released what little air he had left in his lungs. With a desperate plunge, he tried once more, summoning every ounce of strength.
This time, a small crack appeared—then suddenly a three-foot chunk of wall fell away.
Almost too shocked to react, Dirk let go of the tank and kicked through the hole. The surface was only ten feet away. He stroked upward and broke into the blinding sunlight with a rush, gasping and sucking at the fresh air. He floated in the water for nearly a minute before the oxygen was replenished in his blood and his breathing eased. Trying to relax, he stared at an empty sky, ignoring something in the water that brushed at his side. When his breathing slowed, he turned to see what was nudging him.
It was the body of Dr. Torres.
19
Dirk reacted quickly, swimming to a small rock outcropping and towing Torres’s body behind him. Once on land, he noted the three bullet wounds in the professor’s chest.
Dirk looked up toward the van and shouted Summer’s name. There was no reply. Then he saw a small cloud of dust wafting over the ridge. He ditched his mask and fins, fumbled through Torres’s pockets for the keys, and sprinted up the hill. He saw the frayed rope tied to the vehicle and knew someone had come for the stone. Glancing with fear at the water below, he saw no sign of Summer’s body. She must have been abducted.
Disregarding its four flat tires, Dirk started the van, turned it around, and mashed on the gas. The van lurched ahead, its flattened tires thumping against the wheel wells. Despite the uneven traction, Dirk coaxed the vehicle to the top of the ridgeline. Far below, he spotted a white Jeep driving north on the old dirt road.
He fought the urge to turn down the ridge and follow the Jeep. It would be impossible to catch it in the van’s disabled state. He’d already lost one of its shredded tires. Assuming the van reached the road, the many patches of soft sand would surely snare it for good.
From his review of the topo map, Dirk knew the road wound around several hills along the base of Lomo del Torro before curving west and leading across the Zimapán Dam. The dam spanned a narrow gorge at the ridge’s far end. If he could coax the van along the top of the ridgeline, he would cut off a mile or two and possibly catch the Jeep before it crossed the dam.
He punched the accelerator and rumbled across the ridge’s rounded peak. One by one, the remaining tires shredded off. The steel wheels let out a grinding wail, and every bump and dip rattled throug
h the chassis. Dirk felt like he was riding a jackhammer. In the side mirrors, he could see a trail of sparks erupt whenever the wheels scraped over solid rock.