The moment Yarec was out, he was moving like a cat.  It took him only a couple steps to adjust to the feel of the slick cement underfoot.  He crept up toward the first gaping black mouth that opened on the left.  He had only the small light on his wrist to illuminate the way now.  It was getting darker outside, and there was no longer any useful illumination reaching him from the entrance.  He reached the edge of the empty doorway and crouched down to peer inside.  There did not seem to be anything there—just puddles of dirty water and spots on the ceiling where the limestone and cement were being converted into narrow stalactites.  The passage, perhaps four meters wide, bored straight away into the darkness, as far as Yarec’s feeble illumination extended.

He walked a few paces down the horizontal hall, splashing cloudy fluid on his waterproof boots.  Nothing seemed to change as he moved, and there was nothing suggestive of recent human habitation.  So he turned around and headed back to the stairs.  He headed up to the next hallway, which was larger and less saturated with moisture.  He cast a faint light around the lip of the doorway.  This hall looked no more promising, except to the extent that it was higher above the water level and thus a bit more commodious.  Yarec opted to follow this tunnel further, although he had little choice, since the stairway ended at this level.

Yarec stuck to the left wall.  His jacket was impervious to the water trickling down the wall, although he could feel its slickness through the vat-grown fabric.  With a tap, he turned up the output from his wrist light; however dim he might have tried to keep it, anyone on guard would still have seen him coming a long way off.

The passage started bending to the right, with a gradual curve and a slight incline.  The hall should lead up into the chambers carved directly out of the mountain.  There had been some minerals in the heart of the rock, but mostly the upper excavations had been used for storage and workshop space.  Since the facility had closed down—mining contractors and particle physicists packing up their most valuable machines and leaving the rest to corrode away in the dilute mist of chemical effluvium—various parties had operated out the upper chambers.  Vagabonds, brigands, and especially smugglers had camped here and stored their materials.  However, as the population of the surrounding lands drifted slowly away, the location became less and less viable as a base of operations, and the place had of late been quite abandoned.  Even the handfuls of casual visitors who might occasionally have happened by were generally deterred from entering by the flow of the Little Snail River.

Yarec reached a junction.  On his left was a mostly natural chamber, with rock formations that looked heavier and ropier than those in the drill-cut caverns.  the floor had been cut smooth, so that carts and vehicles could be wheeled across it, but the ceiling was an irregular mass of sagging draperies, mostly dull gray-brown, but occasionally shot through with ocher.  Humans had stopped using this place, except as an occasional stopover, long ago.  So there were no visitors to see these formations.  Yet there was another cracked plaque bolted heavily to the wall.  The engraved letters, now dripping with miniature stalactites of their own, identified each of the largest limestone formations—which had facetious names like “cave parrot” and “sarsaparilla Buddha.”  These pareidoilic artworks might have lain unseen for decades, unless the most recent arrivals in the mine had also stopped to marvel at them.

Yarec gave the formations a few minutes of his time.  Then he needed to move on.  There were several exits.  The two on the far side of the cavern were both small; they were natural tunnels that had been widened to allow humans easier access to the further galleries beyond.  However, there was another much larger archway as well, right beside the one through which he had entered.  It angled slightly downwards, at roughly right angles to the passage that had brought him up to the glistening cave.  It was difficult to be sure, amid all the dripping water, but he thought he saw evidence that something had travelled that way recently.

The hallway sloped down, and Yarec eventually saw that it opened onto a large chamber.  He turned off his light and felt his way with an outstretched hand, since there were traces of illumination coming from the cavern.  Pale white fingers traced up across the tunnel’s mouth and grasped vainly against the ceiling of the passage.  The light was too faint to reveal anything about the contents of the room, but its presence was a sure indication of contemporary human activity.

There were no indications that anyone had heard Yarec approaching or seen his light, but he had to be alert to the possibility that he had been noticed.  Whoever was there might have set an ambush.  Yarec squatted down, as unobtrusive as he could make himself, but he still felt exposed.  His ankles were in cold water.  His breath sounded absurdly loud, although the rational part of him recognized that even the slow dripping of water from the ceiling was actually louder.  The drops had a weird syncopated rhythm; half a dozen stalactites were producing drops, each of a different size and marking a different beat.  It was the kind of sound pattern that people played through wireless earbuds as a relaxation aid.  And gradually, Yarec also was able to relax.  He waited long enough to be assured that no one was coming to find him.  Then he started advancing again, slopping almost silently, in a cougar-like crouch, toward the dim gray aperture at the end of the hall.

There was a trickle of current moving down the slight incline.  It ran from one shallow, ragged-edged tarn to the next.  At the end of the hall, the floor fell away, and Yarec was at the top landing of an ancient metal staircase.  The landing was a grille, perforated with holes, through which  the mineral-rich water dribbled, leaving a craggy crust of wet limestone dangling down into space.  A heavy railing, corroded but still thick and solid-looking, enclosed the landing, then angled down to the right, following the metal stairs’ descent along the concrete wall.

From his vantage at the tunnel mouth, Yarec could see that the chamber it opened on was vast—dozens of meters high.  The wan play of light revealed a flat ceiling, about as far above the landing as the landing itself was above the floor.  He could not determine the horizontal extent of the chamber.  It was too huge for the light of the inhabitants’ single electric lantern to penetrate to the farthest corners.  The light source itself was situated near the base of the stairs, on top of a grimy plastic crate.  Either its rare earth battery was almost out of power, or it had been turned down to a minimal intensity intentionally, to conserve.  However, the weak illumination was enough to limn out the forms of five seated humans.  Around them rested a clutter of oddments and useful devices—a makeshift table stacked with mismatched bowls and cups; soft bedrolls sheltered under transparent tarpaulins and elevated off the wet floor in various ways; and a long box like a coffin with vaulted lid.

One of the people said something, and the others reacted.  One of them stood up and walked over to fetch something; it might have been a pot of stew or gruel.  She sniffed at the contents, then prodded them with a wand-like implement.  The four figures still sitting had all turned to follow her movements, and one of them asked her a question, to which she replied in a monotone.  None of their words were intelligible, amidst the omnipresent drip and thrum of the tiny cascades.  However, from the intonation, Yarec guessed that they were speaking the common local dialect.

Someone else stood up and went to join the woman, who was still poking at whatever was in the vessel.  They all seemed completely oblivious to his intrusion—going about their mundane tasks, worried about supper and whatever else.  That left him with a choice.  He probably could have shot them all dead before any of them could really react, but he was not here on an assassination mission.  The mere fact that these people had not noticed his approach and had left themselves to Yarec’s mercy suggested that they were not part of a militarized threat.  Either that, or they’re really, really slick, and they’ve fooled me into letting down my own guard, Yarec admonished himself.

For a while, Yarec just watched.  The inhabitants moved around some more.  One of them laid out dishes for a modest meal, and another disappeared into the great darkness of the chamber.  Yarec strained to make out what he said as he strode away, feet splashing heavily through a centimeter-deep puddle that sat adjacent to the encampment.  It might have been something about “rust traps,” by Yarec could not be sure.  The last person to leave her seat strode four paces over the vaulted sarcophagus and placed her hands on the lid.  Her back was to Yarec, and in the dim illumination, he could not discern what she was doing, but she stood there for quite a while, while the sludge was portioned out at the dining table.

Yarec drew back from the brink of the chamber.  He could have spied on the inhabitants a while longer, but eventually he would have to show himself.  He particularly did not want to wait until he was noticed.  If he revealed himself voluntarily, that gave him the initiative.  Moreover, since these inhabitants were potentially friendly, it would be better for him not to be discovered skulking around; forthright exposure would do a lot more to engender trust.

It took them all day to reach their destination.  Far behind the boat, Yarec spotted a dark speck—a rare carrion bird following them through the wilderness.  It must be hungry, and they were potential food.  For humans or condors, this was lonely country.  There was no road nearby now, and the three men in the boat ought to have been the only humans around for many kilometers.  Yarec thought he spied a snake once, basking near the river bank, but it might just have been an oddly bent yucca stalk.  There was hardly any other visible animal life, apart from the scorpions and insects.

The sun had sunk low, and the dust in the air made its light look tired and red, before they finally saw the massive hill they were seeking  Beneath it, the Little Snail River ended its above-ground flow.  “There, that’s where the Georgiansen Mine is,” Thad Solara said, pointing with his half-gloved hand.

“I see,” said Yarec.  He had spotted the small mount himself, and he could see that the river was headed directly towards it.  “The river goes straight in, right?” he asked.

“Sure does,” Thad said.  “I’ve never paddled past the first big room myself,” he went on.  “No real reason to.  But I know you plan to poke around under there for a while.  There are lots of ways to go once you’re inside, so I hope you know where you’re headed.”

“Yeah, thanks,” Yarec said.  He was listening, but only with part of his attention.  He had maps to run through in his head and plans to revisit.  The sun sank deeper as they rode toward the entranceway, and by the time the boat reached the massive concrete arch, Yarec felt confident that he was ready to go.

Water had flowed through the caverns under the hill, off and on, for thousands of years.  Now, as the river approached the entrance, the flow quickened, eager for the plunge underground.  The opening had been widened and reshaped by human tools—lined with cheap concrete to make an arched gallery.

“Watch your head,” shouted one of the pilots, even though the entryway was at least five meters high.  However, as the boat passed into the shadow of the arch and Yarec’s eyes adjusted to the reduced illumination, he saw that the warning was less superfluous than it might have seemed.  Rainwater, trickling down through the rounded mountain above their heads, had cracked through the molded ceiling.  Laden with minerals, it dripped down, leaving a few microscopic grains behind with each drop.  The results were delicate limestone soda straws, hanging down toward the river course.  They were impressively long, in spite of their obvious fragility.  If Yarec had jumped up and rammed one with his forehead, it would have undoubtedly been worse for the rock formation than for his brow.  Still, he ducked his head, feeling as if he owned the slow powers of the earth some respect.

The huge steel gates that had once blocked the entrance tunnel at its midpoint were long gone.  What remained were pieces of their great hinges, discolored and lumped with bits of flowstone.  Just past these protrusions, a small plaque was bolted to the wall.  Dirty and weathered, missing a corner, it commemorated the discovery of a species of weakly interacting elementary particles.  The particles had been produced in astounding profusion in the first few minutes of the universe and lingered, drifting aimlessly across the wide spaces between the stars, without ever interacting again.  There was a ball of them around the Milky Way, held in place by the galaxy’s gravity while the Earth swam through them.  Clever scientists had set up detectors in the basement of the old mine, to detect the rare instances when such esoteric particles would actually collide with atoms and recoil.  The huge weight of the mountain shielded the sensors from the cosmic rays that were constantly impinging on the planet’s atmosphere.  When the new elementary particles were finally observed experimentally, the discovery was celebrated around the world.  It was thought at the time that they might account for most of the mass of the universe.  That hypothesis was quickly ruled out, but what actually accounted for the apparent weight of the cosmos was never figured out; the transcontinental scientific community had turned away from elementary particle physics, as limited resources forced people to focus on more immediately useful researches.

Yarec glanced at the plaque as they slid past, looking at the names, recorded in stylized ancient letters, of the women and men who had labored for so many hours beside their cryogenic equipment, waiting for three or four clicks produced by relics from the birth of the universe.  They must have been dedicated people, Yarec thought, searching for fossils from the dawn of time.  Then he turned and looked ahead again, down toward the delving’s first great hall, and the silty lake that occupied it.

The river led into a vast cavern which had been excavated to many times its natural size.  The water spread out into a long black lake.  Slow ripples glittered in the boat’s floodlight, as the current drained gradually downward.  Far below, Yarec knew there was a tumultuous underground sea.  When the flow reached a precipice, it plummeted down an old elevator shaft, dropping more than two kilometers to what remained of the deepest chambers.  At the bottom, the crashing waters flooded down empty veins of ore and eventually fed an underground river heading south.  It was extremely unlikely that Yarec would need to descend that far, but he had studied the geography of the uppermost flooded chambers anyway.

Whoever had taken up residence here would not be dug in so deep, if they were still in the caves at all.  A group of five people, fairly well armed and carrying a large container between them, had been spotted by a passing airplane.  The group was less than half a kilometer away and headed straight toward the mine.  The aircraft was performing routine passive reconnaissance while ferrying passengers and supplies across the region.  The people carrying the container had not aroused any particular suspicions at the time; at worst, they were probably just bandits.  Subsequent overflights had seen no signs of the group, but for a number of other reasons—not shared with Yarec—it had been decided to send someone on the ground to check things out.

The Solara brothers were under contract to bring Yarec here, but they were not going to follow him any further into the underworld.  They would remain nearby, to provide medical assistance if he emerged from the caverns in need of it, and to provide transportation back to Kruppeen when he was finished.

The brothers brought their canoe up against one wall of the cavern.  They had stowed the motor, and the sounds of their paddles slapping against the water echoed off the arching concrete walls.  Yarec found a place to alight.  The remains of a staircase emerged from the murky waters.  Yarec climbed out of the canoe and followed the slick, crumbling steps up along the curve of the wall.  The boatmen spun their craft around, and it seemed only a few moments before they had disappeared from sight, the remains of their sharp white light retreating around the corner.