Brockton was working on a robot probe designed to take samples from the hottest vents when he felt the first vibration. It was accompanied by a muted rumble, as if one of the back doors had been opened. A glance showed that both of the big service bay barriers were still shut. With a shrug, he returned to his work. He was alone in the shop except for the automatics, Norquist and Oppervann having decided to take a long lunch. They did not have many opportunities to interact with the scientific staff and took every chance to do so. To improve their education, both men insisted. To try to put the make on one of several attractive unattached ladies among the staff, Brockton knew.
Nothing more than casual flirting for him. He had a wife and two kids on Tharce IV. He was here because he didn't mind the desert, and because in a year on Comagrave he could make the equivalent of three years' salary back home. His family understood. When his contract was up, he would be able to take a whole year off doing nothing but watching his kids grow.
Though considered a party-killer, he got along well with his workmates. His skills, honed through fifteen years of experience, were greatly appreciated by both his colleagues and his employers, and he did not try to play the disapproving father figure to his predominantly younger coworkers. Removing his hands from the interior of the probe, he shut the access panel, picked up the nearby magnetic welder, and began to reverse the polarity on the interior latches. Once flopped, they would hold the panel shut as securely as if it had been melted into place.
There it was again. A second tremor, stronger than the first. He had picked up enough geology from hanging around the station's scientists to know that where geysers and thermal pools are present, stronger seismic activity was to be expected. But this didn't feel like one of the numerous minor temblors he had experienced many times during the preceding months. It had a different feel to it - more of a bump than a rumble.
The station was constructed on a flexor foundation that was designed to distribute any shock evenly across its base. Anything short of a tectonic convulsion would be dissipated by the integrated flexors before it could cause any damage. The contractors had known what they were doing. Though he had not worked in construction, Brockton had seen enough to know good work from bad. Upon arriving, he had taken an off day to make his own inspection of the station and its outlying structures. Everything had looked reassuringly solid.
That was when the ground fell away and the roof started to come down on top of him.
The roar that accompanied the collapse was frightful, a caustic clamor in the ears that masked the screams of those crowded into the central dining area for lunch. Feeling the floor fall away beneath him, he grabbed wildly for the probe. It was plunging downward as well, until he managed to hit the open programming panel. Bluish light emerging from its flat underside, the probe rose and steadied on its tiny repulsion field. Brockton's terrifyingly rapid descent slowed. Kicking the field up to full power, he found that the probe could muster just enough lift to keep them both aloft. For how long he did not know.
Then the rest of the roof came down.
Guiding the probe, he made a mad dash for the nearest crumpled doorway. He just did manage to slip through a rip in the crumpling, warping fabric. Outside in the glare and steam of the day, he turned his head to look back in the direction of the station. Keeping both arms and legs wrapped tightly around the laboring device, he tried to make some sense of what he was seeing.
The entire station - central hub, communications tower, living quarters, lab modules, service departments, hygienics plant - was collapsing in upon itself. No, not upon itself, he saw through the rising, swirling mists. Into a gaping cauldron. A roaring river of boiling water had suddenly manifested itself directly beneath the station. With nothing to support it, the advanced flexor foundation was no more useful than a row of wooden pilings.
Despite the damp heat, he was having chills. Rising above the groans and grindings of imploding buildings were the screams of those trapped inside. A few who had been near the front exits had tried to escape that way, only to find there was no place to escape to. Like those they had left behind, they died before they could reach solid ground, crushed beneath the subsiding structures or boiled alive in the torrent that had burst forth beneath their feet.
In less than an hour there was nothing left of the supply station. It had been swept away, down the steaming cataract that now gushed from the side of the rise and into the nearest expanse of hot lake. A couple who had been out all morning studying cyanotic bacteria returned in their aircar and pried his cramped arms and legs off the probe that had saved his life. Another researcher returned later that evening. He was accompanied by the resident AAnn advisor. Decamping on a mound of solid, well-vegetated ground half a kilometer away, the numbed survivors tried to make sense of what had happened.
Brockton knew what had happened. He had survived to feel his wife next to him once more, and to hold his children. As soon as rescue teams arrived, he was putting in for a pysch dismissal. He doubted he would have any trouble getting one. Not after what he had seen.
Norquist, Oppervann, all those other fine men and women - all gone. If the rescue teams were really lucky, they might be able to recover some bones. Sitting on the ground beneath an orgthic bush, he hardly heard what the others were saying. It was starting to get dark, and he was cold. Surrounded by hell, he was cold. Of everything his fellow survivors said prior to the angelic arrival of the first rescue craft, only a few words of the AAnn, speaking in clumsy Terranglo, remained forever stuck in his memory.
"Ssstt, we told your engineerss not to build on that ssite!"
The stitcher's harpoon struck the underside of the aircar with a familiar shrill thwack. Leaning cautiously over the side, Elrosa saw it wriggle out from under the sand, all three of its protruding, bulbous eyes triangulating on him, their intended prey. He wondered what, if anything, the voracious alien mind behind them was thinking. As he thrust his scanner over the side of the vehicle, he watched as the meter-long harpoon was slowly retracted. The stitchers learned quickly: It would not expend its killing mechanism on the armored underbelly of the aircar again.
So powerful was the expelled harpoon of a stitcher that it could penetrate the underside of a normal vehicle. Elrosa and Lu's aircar was not normal. It had been given a ventral sheathing of glistening golden percote that would have been more appropriate to a military transport. Nothing merely organic could penetrate that layer of sprayed-on armor. It reduced the aircar's speed and range, but not significantly. And it allowed the two biologists to proceed in comparative safety with their study of several varieties of desert-dwelling predator.
Another hopeful thwack . Another subsurface hunter disappointed. This was turning out to be an excellent study area.
The stitchers were one of several unique carnivores that lived and hunted beneath Dawn's scattered sand seas. They impaled their prey on long, sharp harpoons built up of concentric layers of hardened calcium carbonate. It was as if a human had learned how to sharpen a femur, spear it into prey, and reel the resultant kill back in by means of the ligaments still attached to the bone. Since no one had yet dissected a stitcher, the means by which their harpoons were propelled at such remarkable velocity remained open to explication. Elrosa favored compressed air as a nontoxic and readily renewable means of propulsion. Lu came down on behalf of those who postulated the existence of multiple knots of rapid-twitch muscle fibers.
They were not out today to catch and dismember - only to take measurements. Elrosa was duly excited by the work they had accomplished over the past several days. There were more stitchers per cubic kilometer of sand sea in this area than anyone had previously encountered anywhere else. Lu thought it might be a mating territory. Stitchers mating - now that would be a ripe subject for a monograph!
Another lackluster thunk sounded as a harpoon struck the impenetrable underside of the aircar. He smiled to himself. It would be useful to know if the stitchers considered the low-flying intruder a thre
at or a possible meal. Perhaps both, he mused. Previous fieldwork indicated that the predators sometimes appeared to hunt in tandem, or even in small groups. He and Lu had seen no evidence of pack hunting thus far, but like everything else on Comagrave, organic or otherwise, very little was known with assurance.
Behind him, his partner shouted a verbal command to the aircar console. It complied, and they found themselves jetting silently forward, leaving frustrated stitchers goggling in their wake. Only the predators' eyes and expended harpoons were visible above the surface of the dune.
Another sand-filled depression beckoned. With luck, they might find a line or two of migrating geulons, or a new species. So recently arrived were humans on Comagrave's surface that it was the unfortunate biologist indeed who did not return from a field trip without at least several new species to record. Taxonomy was almost as exciting as actually encountering the creatures in question.
Leaning over the open side of the car, careful to keep himself as small a target as possible for anything inimical that might be lying camouflaged under the sand, he directed Lu to shift them another ten meters northward.
"That's good!" He gestured with his upraised right hand. "This looks like a promising spot."
His assumption was correct. Every day, they grew more skilled at predicting the movements of the planet's endemic wildlife. No sooner had the aircar hummed to a halt than not one but three loud thwack s, one after another like shots from a gun, rapped on the underside of the vehicle.
Lu joined his friend at the edge. The air suspension craft hovered effortlessly some three meters above the sand. "There!" Lu pointed to where a brace of eyeballs, like pale white melons, protruded from the sand. Recorders were brought into play.
As they clicked away, Elrosa heard a decidedly different kind of thunk . It was higher in pitch, more immediate, and sharper of sonic detail. Turning, his eyes widened slightly as he saw the meter-long calcareous lance quivering upright in the deck. It had penetrated the plastic sheeting to a depth of a fifth of a meter. As he stared, a soft whistling sound drew his gaze upward.
"Look out!" Throwing himself to the side, he just did avoid the descending tip of the stitcher harpoon. It slammed into the deck centimeters from his scrambling right foot.
Rolling over, Lu stared in astonishment at the impressive weapon. "They know that there's food up here - us - that they can't get at from below. So they've started firing into the air, hoping to impale us on the way down. Amazing!"
The aircar was equipped with a retractable cover, but one designed to offer protection only from the weather. A harpoon would go through it like a vibrablade through gelatin. As Elrosa climbed to his feet and took a step toward the control console, a vast whistling suddenly filled the air, as of an approaching dustdevil. Lu let out an inarticulate cry and dove for the open hatch that led to the tiny, enclosed head.
He didn't make it.
Assembling silently beneath the sand, the pack of stitchers must have fired at least fifty harpoons.
Though its power pack was approaching empty, the aircar was still hovering in place when one of the several search teams sent out to look for the two biologists finally found it. Of the two biologists who had been aboard, there remained only bloodstains on the deck, and on the side where their harpoon-impaled bodies had been dragged from within by the hungry stitchers. Studying the scene of quiet butchery, the newcomers conversed in subdued whispers interrupted only by the occasional thwacks of harpoons striking their craft's underside and armored roof.
When the sole AAnn aboard suggested that perhaps she and her kind should take over field study of the stitchers, or at least supervise the work, the human in charge readily agreed. If the AAnn wanted to deal with such cunning carnivores until such time as enough was known about them to work their territories in comparative safety, he saw no reason to argue. Let the reptiloids be the ones to put their lives at risk.
"There will be less rissk for uss," the AAnn assured him sympathetically. "We are ussed to living in the ssandss, among thosse kindss of creaturess that make their homes thussly. You will, of coursse, receive copiess of all reportss as they are prepared, and will be kept fully up to date on all our progress."
"Fieldwork is usually better carried out by the many than by the few," the dejected human supervisor concluded. Another time, under different circumstances, he might have felt otherwise, but he was distraught over the unexpected loss of two of his colleagues. Besides, where was the harm in sharing field assignments with the willing AAnn? They were more at home in this kind of country than any human, and their willingness to share data had already been demonstrated. Let them do some of the hard work. With an entire new world to study, catalog, analyze, and report on, his staff was already stretched thin. They could find plenty to occupy themselves besides stitchers.
"I don't understand." Hibbing stood by the side of the glassine tower and stared dubiously at the readouts embedded in its smooth, curving side. "Everything was fine as of this time yesterday." Nearby, Tyree and Souvingnon were examining the contents of the relay box that hugged the side of the tower close to the ground.
Tyree glanced up. "Everything's working, sir. The extractors just aren't pulling any water."
Turning, Hibbing saw his eyewrap darken as he gazed eastward. The site that had been chosen for the main settlement on Comagrave commanded a sweeping view of the spectacular Carmine Cliffs, a geologic upthrust averaging a thousand meters in height that ran for hundreds of kilometers from north to south. Below and to the west were the Bergemon Salt Flats, a perfectly flat pan devoid of vegetation, subsurface liquids, or tectonic instabilities. To the north lay the maze of narrow canyons known as the Fingerlings. One of the most biologically rich areas on the planet, it was but a short journey from the outskirts of Comabraeth community.
Beneath the settlement site, hydrologists had located a sizable prehistoric aquifer big enough to provide a six-hundred-year supply for a city of half a million. A better place to establish the colonial capital of Comagrave could not be found on the planet. There was water in abundance, more than ample landing space for shuttles and aircraft out on the pan, biological and geological riches practically within walking distance. Months had passed without a hint of trouble, during which time the village had grown into a thriving small town of more than ten thousand. There was talk of formalizing it as the capital of the incipient colony.
And now the water, every million acre-feet of it, was gone. Or so his hydrotechs were telling him.
Reluctantly, he lowered his gaze from the glorious, multihued vista spread out before him. Comagrave was not yet developed enough to be able to accommodate tourists, and his position never allowed him longer than a minute or two to be one himself. "How could this happen?"
Souvingnon rose to confront the administrator. At his feet, Tyree continued to fiddle with instrumentation, as if by so doing he could somehow will the water to return. "There are possibilities. Since the original discovery dated the top layer of water to several hundreds of thousands of T-standard years ago, it seems pretty clear to me that the only way it would suddenly vanish is if some radical new regional development did something to affect the underground geology."
Hibbing nodded slowly. "And the only new regional development is us."
Souvingnon gestured in the direction of the extraction tower and the attached processing and filtration plant. "Everything above ground is working perfectly. So we have to assume that the problem is subterranean in nature. Personally, I've never heard of an aquifer that big disappearing this fast. But this is a new world. Geology isn't even a perfect science on Earth." He turned thoughtful. "This region might not be as seismically stable as the original surveyors first assumed. There might have been a catastrophic collapse in the shale strata underlying the aquiferic sands. It could have been set off by the continual vibrations of shuttlecraft landing and, especially, taking off."
"That doesn't sound very reasonable."
Souvingnon sighed
. "Since we don't have a reasonable explanation for what's happening, I'm starting a search for unreasonable ones. The aquifer is broad, but not deep. Realistically, a subterranean collapse on such a scale is unlikely. Theoretically, it's possible."
"What can we do?" Hibbing turned back in the direction of the town. "I've already activated emergency rationing procedures. I'm responsible for the health and well-being of nearly fifteen thousand people, Souvingnon, every one of whom needs to drink and occasionally to wash. We don't have a waste problem - the solid-waste decomposing system needs no water - but I'm going to have to start having supplies tanked in from the Broughlach River. That's three hundred k's from here. A couple of months of that will bankrupt our municipal operating budget. As you know, initial planetary R and D stopped supplementing that over a year ago."
And I'll be replaced, he thought to himself. They'll send me somewhere quiet and out of the way to decompose, just like the town's solid waste. Hibbing did not want to be replaced. He liked his job, liked the beauty and solitude that Comagrave could boast in plenty. It was why he had applied for the position of colonial administrator in the first place.
"We can drill elsewhere." Souvingnon pointed across the valley, to the colorful crimson rampart. "Maybe at the base of the cliffs."
"Maybe." Hibbing was dubious. "But the initial hydro surveys chose this spot because there was water in plenty here. And if the shuttle landings are responsible for what has happened, who's to say the underground water table hasn't been collapsed everywhere in the vicinity?"
Tyree finally rose from his inspection, brushing dust from his hands. "We could ask the AAnn."
The AAnn had a very small deeded scientific outpost to the west of the town, near the edge of the salt pan. They had no view of multihued cliffs, no easy access to the valleys of the Fingerlings. As Hibbing understood it, there were no more than forty individuals working at the reptiloids' outpost at any one time. Insofar as he knew, they had their own water supply. An emergency line could be laid across the pancake-flat edge of the pan from the alien outpost to the town in a fraction of the time and cost it would take to build one to the Broughlach River.