Kowalski swore as he stepped out.
Hank covered his mouth, offering up a small, “Dear God…”
The tunnel emptied into a large cavern, tall enough to house a five-story apartment building. Overhead, the roof was perfectly domed, as if the chamber had been formed out of a bubble in the limestone. Only this bubble had cracked long ago.
To the left, a wide fracture high up the wall allowed a river to gush forth, pouring down into the cavern in a turgid fall — but it was not a river of water. From the crack, black mud boiled and flowed, popping and spewing a sulfurous steam, as it ran thickly downward. It pooled into a great lake that filled half of the cavern, fed additionally from a dozen trickles weeping out of smaller fissures in the wall. The pool then emptied into a gorge that split the cavern. Down that chasm, a river of seething mud, bubbling and roiling, swept past, until it vanished down a dark gullet on the far side.
“Amazing,” Hank said. “An underground river of mud. This must be one of the geothermal arteries flowing all the way through the Colorado Plateau from the San Francisco range of volcanic peaks.”
But they weren’t the first ones to discover this giant artery.
An arched bridge, built of long, narrow slabs of sandstone, all mortared together, spanned the steaming gorge. The pattern and design were readily identifiable as the handiwork of the ancient Pueblo Indians.
“How did anyone build that down here?” Kowalski asked.
Hank answered, “The old tribes of this region were phenomenal engineers, capable of constructing extensive and complex homes halfway up sheer cliffs. This bridge would be easy for them to make. Still, they must have hand-carried each of those thin slabs down here.”
The professor’s eyes went glassy — either from the sting in the air or from imagining such an engineering feat. Hank moved forward. A jumble of broken rock littered the cavern floor, but some ancient hand had cleared a path to the bridge long ago.
Painter followed, knowing the professor’s goal. A similar path threaded from the far side of the span to a tunnel opening in the opposite wall. It seemed that their journey through this subterranean world wasn’t over yet.
As they approached the bridge, the heat spiked to a blistering degree. The air grew nearly impossible to breathe as its sulfur content swelled. The only reason they’d made it this far was that the continuing breeze sweeping through the cavern flushed the worst of the toxins up the shaft behind them.
“Do you think it’s safe to cross?” Kowalski asked, hanging back with Hank, who looked equally uneasy.
“This bridge has stood here for centuries,” Painter said, “but I’ll go first. Alone. If it looks okay, I’ll have you follow one at a time.”
“Be careful,” Hank said.
Painter intended to be. He stepped to the edge of the bridge. He had a good view down into the chasm. Mud bubbled and spat, splattering the limestone walls to either side of the gorge. It would be instant death to fall down there.
With little choice, he placed one foot on the span, then the other. He stood for a breath. Seemed solid enough, so he took another step then another. He was now over the gorge’s edge. Hearing sandstone grating slightly, settling a bit under his weight, he waited, swallowing his fear. Sweat trickled in streams down his back. His eyes watered and itched.
“Are you okay?” Kowalski called.
Painter lifted an arm, acknowledging that he was fine, but he feared calling out. This was foolish, of course. He continued onward, step by step, until finally he reached the far side and happily leaped to solid ground.
Relieved, he leaned down, resting his hands on his knees.
“Should we follow?” Hank yelled.
Painter merely lifted an arm and waved them over.
In short order, they all crossed and made it safely to the far side. After a moment to collect themselves, they headed toward the dark tunnel, leaving the muddy caldera behind them.
Once they reached the mouth of the passageway, they were rewarded with a cold breath blowing out of the tunnel. The air had a mineral tang, but it was a welcome respite from the sulfurous burn of the cavern.
Kowalski held a hand to the breeze. “Where’s this coming from?”
“Only one way to find out.” Painter led the way again.
Hank offered a more detailed answer as they headed down. “The cavern system must extend much farther underground. For a cave to breathe like this, it takes a great volume of cold air below.” He pointed behind him. “That hot cavern is drawing the chilled air upward, and the breeze continues from there to the surface, flushing that heat upward and out.”
Painter remembered the volume estimate of the cavern system beneath Wupatki’s blowhole. Seven billion cubic feet. He sensed that this was bigger. But how far down would they have to go?
The tunnel continued deeper, turning steeper in some spots, almost flat in others. But it never turned upward. The way also grew steadily colder. After another ten minutes of hiking, a pearly sheen of ice began to coat the walls, reflecting the beam of Painter’s flashlight. He remembered Nancy’s story of the icy lava tubes that lay beneath the cone of the Sunset Crater. The same phenomenon was happening here.
Soon, even their footing became more treacherous. Kowalski took a hard fall and cursed loudly. The breeze blew stronger, the icy chill burning Painter’s cheeks as readily as the sulfuric heat had some minutes ago.
“Is it just me,” Kowalski asked as he picked himself up, “or is anyone else thinking of the phrase when hell freezes over?”
Painter ignored him as his light revealed the end of the tunnel at last. He hurried forward, half skating on the slick surface. He slid into another cavern and stopped once again at the entrance, stunned by what he saw before him.
Kowalski whistled sharply.
Hank gaped in awe. “We’ve found them.”
Painter knew what he meant.
They’d found the Anasazi.
“It’s almost like watching a video game, n’est-ce pas?” Rafael asked.
He sat in the rear cabin of a surveillance helicopter — one of two aircraft borrowed at some expense from a private militia group who spent time patrolling the Mexican border for “narco-terrorists.” With heavily tinted bulletproof windows and engines idling, the two helicopters sat in the desert about a mile from the mesa.
The rear cabin of Rafe’s craft was equipped with two captain’s chairs that swiveled easily between a bench seat on one side and an entire wall of equipment, including digital recorders, DVD players, a bank of three LCD monitors, all of it tied into microwave receivers and cameras bristling on the outside.
On the center LCD monitor, a jangling view revealed a team climbing up a crack in the mesa’s side, aiming for the ruins on top. The feed came from Bern’s helmet-mounted camera, allowing Rafe to once again monitor the assault.
He turned his chair to face Kai Quocheets, who sat on the bench seat beside one of Bern’s teammates. She stared sullenly back at him with her arms crossed in front of her. Clearly still furious about his betrayal, she hadn’t said a word since they’d left the pueblos after the shooting of the two elderly Hopi natives. He felt a bit bad about that. He admitted to himself now that it had been a feckless act on his part, one beneath him, but he’d been sore from the ride to the pueblos and already in a foul temper over how the old woman had resisted his interrogation. He now truly believed the elderly pair knew nothing.
A waste.
And if the young woman hadn’t been so obstinate, he might have thrown her a bone, but instead he let her sulk.