Summertide hu-1

by Charles Sheffield

  So why had Atvar H’sial left her, then fed her and given her protection, when Summertide would get her anyway?

  There had to be an explanation of what had happened. She had to think.

  She crouched down by the water, seeking a spot partly shielded from the blowing dust. If Atvar H’sial had wanted to kill her, the Cecropian could have done it very easily while she still slept. Instead she had been left alive. Why?

  Because Atvar H’sial needed her alive. The Cecropian did not want her at the moment for whatever intrigue was being arranged, but Atvar H’sial needed her later. Maybe for something she knew about Quake, or about the Builders. But what? Nothing Darya could imagine.

  Change the question. What did Atvar H’sial think Darya knew?

  Darya could make no rational suggestion, but at the moment she did not need the answer. The new Darya insisted that reasons for actions were less important than actions themselves. The thing that mattered was that she had been left here in cold storage — or hot storage — for an indefinite period; someone, sometime, might be coming back for her. And if she did nothing, she would quickly die.

  But it would not happen that way. She would not let it happen.

  Darya stood up and surveyed her surroundings. She had been Atvar H’sial’s dupe once, arranging for the trip up the Umbilical. That was the last time.

  The lake she was standing by was the highest of half a dozen connected bodies of water. Their sizes ranged from less than a hundred meters across to maybe four hundred. The outflow of the nearest pool, forty paces away from her, splashed down a little cataract of one or two meters’ height into the next lake in the sequence.

  She searched the shoreline for some type of shelter. Judging from the weather, it would have to be something pretty substantial. The wind was strengthening, and fine sand was seeping into every open space — including her own open spaces; the sensation was not pleasant.

  Where? Where to hide, where to find sanctuary? The determination to survive — she was going to live! — had been growing.

  She brushed fine talc from her arms and body. Earthquakes might be a long-term danger, but at the moment the biggest threat was this intrusive, hard-blown powder. She must get away from it. And it was not clear that anywhere was safe.

  What do the native animals do?

  The question popped into her head as she was staring down at the lake shore, riddled with what seemed to be animal bore holes. Quake life-forms didn’t stay on the surface at this time of year. They went underground, or better yet underwater. She recalled the great herds of white-backed animals heading single-mindedly for the lakes.

  Could she do the same thing? The bottom of an alkaline pond was not an enthralling prospect, but at least it would get her away from the dust.

  Except that she could not survive on a lake bed. She needed to breathe. There was no way to carry an air supply down with her.

  She waded into the water until she was up to her knees. The water was pleasantly warm, and increased a little in temperature as she went deeper. Judging from the bottom slope, the middle of the pool would take her over her head. If she went in until the water came to her neck, the seals of her mask and air filter would be below the waterline and only her head would be above it. That would keep out the dust.

  But how many hours could she stand like that? Not enough.

  It was a solution that solved nothing.

  She began to follow the flow-line of the chain of lakes, descending from one steplike level of rock to the next. The first cataract dropped two meters through a series of half a dozen small rapids, running over smooth lips of stone until they finally discharged into the largest of the lakes. If anything, the blowing dust was worse here at the lower level.

  She walked on. This lake was roughly elliptical, at least three hundred meters across and maybe five hundred long. Its outfall was correspondingly larger, a substantial cataract that she could hear when she was still forty paces away from it.

  When she came to the noisy waterfall she found a wall of water, three meters high, dropping almost vertically into the next lake of the chain. Spray from the foot of it blew up and fogged her mask, but at least it washed some of the dust from the air. If she could find nothing better, this might be a place to return to.

  She was ready to head for the next pool when she saw that the waterfall actually flowed over an overhang in the ledge of rock. There was a space behind. If she could step through the fall without being carried away by the water torrent she would be in a shielded enclosure, protected from blowing dust by a rock wall on one side and running water on the other.

  Darya moved to the side of the waterfall, pressed herself as close as she could to the rock face, and edged sideways into the rush of water. As soon as she was partway into the foaming white spray she knew she could get through it. The main force of the fall was missing her, arching out over her head in a torrent that sent only noise and blown droplets back to the hidden rock wall. And as she had thought, there was a space behind.

  The trouble was, that ledge and shielded space were too small. She could not stand up without poking her head into the torrent. She could not lie down flat. The ledge was lumpy and uneven. And there was not one square inch of wall or floor undrenched by the continuous spray.

  She began to feel dismay, then caught herself. What had she been expecting, an Alliance luxury apartment? This wasn’t a matter of comfort; it was one of survival.

  With the quilt to protect her, she could curl up with her back to the rock. She could stack most of her food and drink outside, and whenever necessary she could leave her cave long enough to bring in more to eat, or to stretch her legs. She could wash out the mask and air filter when she was inside, to keep it free of dust. And she would be warm enough, even if she was never totally dry or rested. If she had to, she could survive here for many days.

  She went back and made three trips to her cache of supplies. In the first two she carried everything except the beacon over to the waterfall, and spent a long time deciding which items should be inside with her, and which would be left just outside.

  The third trip involved the most difficult decision.

  She could carry the beacon signal generator over to a point of high ground near the lake. She could put it on a heap of stones, to maximize its range. She could make sure that it had adequate power. But would she do something else?

  She thought about it, and knew she had no choice. If and when Atvar H’sial came back, Darya would still be at her mercy, to be used, rescued, or discarded, as the Cecropian chose. Two months ago Darya might have bowed to that as inevitable; now it was not acceptable.

  She wrapped the generator in the quilt and carried it through into the waterfall cave. There she rearranged the waterproof sheet so that she and the beacon were shielded from blown water droplets. It was close to Mandel-noon, and enough light diffused in through the rush of water.

  Slowly and carefully, she switched off the generator and partly disassembled it. It would be a mistake to rush, and time seemed to be the one thing she had in abundance. She knew the basic circuits she needed, but she had to improvise to achieve the impedance that would do the trick. She took the high-voltage alternating leads, and ran their output in parallel to the r/f stage, through the transformer, and on to the message box. Then it was a test of memory, and of long-ago courses in neural electronics. The convolver that she needed was little more than a nonlinear oscillator, and there were resistors and capacitors in the signal generator that could perform dual functions. She could not test the result, but the changes she had made were simple enough. It ought to work. The main danger was that it might be too powerful.

  Mandel was setting before she was finished. The modified beacon went back outside, into the ruddy light of Amaranth and the driving dust storm, and onto its little cairn of stones. Darya activated it, and nodded in satisfaction as the function light blinked to indicate that the beacon was working again.

  She inched her way back i
nto the waterfall cave, swathed herself completely in the quilt, and curled up on the ledge of rock. Stony lumps stuck into her side. The splashing fall provided a continuous spray of droplets and the noise of rushing water. Underneath that was the uneasy movement of Quake itself, groaning as the planet was stretched harder on the rack of tidal forces.

  No one could expect to be able to sleep in such conditions. Darya nibbled on dry biscuits, closed her eyes, and fixed her mind on one thought: she was fighting back. What she had done was little enough, but it was all that she could do.

  And tomorrow, she would find some new idea to save herself.

  With that thought in her head and uneaten biscuits still in her hands, she drifted off into the most restful sleep since she had left Sentinel Gate.

  Hans Rebka had another reason for wishing to be alone. Just before they had left Opal, another encrypted message had arrived from Phemus Circle headquarters. There had been no time to examine it in the haste of their departure, but while the capsule was descending the Umbilical toward Quake he had taken a first look. He had been able to decipher just enough to make him uncomfortable by the time they landed. As the aircar took him north away from Opalside and toward the starside of Quake, the message was burning a hole in his jacket pocket. He put the plane on autopilot, ignored the brooding scene below him, and set out in earnest to work on the message.

  Headquarters had switched from prime numbers and cyclic ideals as the basis for their codes, to an invariant-embedding method. The messages were supposedly almost uncrackable — and vastly more difficult to read, even when you knew the key. Rebka appropriated most of the car’s on-board computer power and began to grind out the message, symbol by symbol. It did not help at all that there were occasional data losses in transmission at the Bose Transitions, adding their own random garbling to the cipher.

  The received signal contained three independent messages. The first, deciphered after three quarters of an hour of patient work, made him want to throw the whole facsimile record out of the car’s window.

  …THE ALLIANCE COUNCIL MEMBER WHO IS HEADING FOR DOBELLE USES THE NAME JULIUS GRAVES, OR APPARENTLY SOMETIMES STEVEN GRAVES. HE IS AUGMENTED WITH AN INTERIOR MNEMONIC TWIN, DESIGNED AS AN EXTENDED SUPPLEMENTARY MEMORY, BUT THAT UNION IS NOT FOLLOWING NORMAL PATTERNS. OUR ANALYSTS SUGGEST A POSSIBILITY OF INCOMPLETE INTEGRATION. THIS MAY LEAD TO VOLATILE OR INCONSISTENT BEHAVIOR. SHOULD GRAVES ARRIVE ON DOBELLE, AND SHOULD HE EXHIBIT BEHAVIORAL IRREGULARITIES, YOU WILL COMPENSATE FOR THESE TENDENCIES AND NEUTRALIZE ANY ILLOGICAL DECISIONS THAT HE MAY SEEK TO MAKE. PLEASE NOTE THAT A MEMBER OF THE COUNCIL HAS PERSONAL DECISION POWERS THAT EXCEED THOSE OF ANY PLANETARY GOVERNMENT CONTROLS. YOU MUST WORK WITHIN THIS CONSTRAINT…

  “Thanks, guys.” Rebka crumpled the message into a ball and threw it over his shoulder. “He’s crazy and he can do anything he likes — but it’s my job to control him and stop him. And if I don’t, my head rolls! Just perfect.”

  It was another fine example of action at a distance, of government trying to control events a hundred light-years away. Rebka set to work on the next message.

  That took another hour. It did not seem much use when he had it, but at least it provided information and did not ask for outright impossibilities.

  …PERHAPS OF NO DIRECT RELEVANCE TO YOUR SITUATION, BUT THERE ARE WIDESPREAD AND INDEPENDENT REPORTS OF CHANGES IN BUILDER ARTIFACTS THROUGH THE WHOLE OF THE SPIRAL ARM. STRUCTURES THAT HAVE BEEN STABLE AND INVARIANT THROUGHOUT HUMAN AND CECROPIAN MEMORY AND IN ALL REMAINING ZARDALU RECORDS ARE EXHIBITING FUNCTIONAL ODDITIES AND MODIFIED PHYSICAL PROPERTIES. THIS IS ENCOURAGING MANY EXPLORATION TEAMS TO REEXAMINE THE POSSIBILITY OF PROBING THE UNKNOWN INTERIORS OF A NUMBER OF ARTIFACTS…

  “Tell me about it!” Rebka glared at the computer that was displaying the offending transcript. “And don’t you remember that I was all set to explore Paradox, before this idiot assignment? Before you dummies pulled me away!”

  …WHILE PERFORMING YOUR OTHER DUTIES YOU SHOULD OBSERVE CLOSELY THE ARTIFACT OF THE DOBELLE SYSTEM KNOWN AS THE UMBILICAL, AND DETERMINE IF THERE HAVE BEEN SIGNIFICANT CHANGES IN ITS FUNCTION OR APPEARANCE. NONE HAVE SO FAR BEEN REPORTED…

  Rebka turned to stare back the way he had come. The Umbilical was long since invisible. All he could see was a broken line on the planet’s terminator, like a glowing string of orange beads on the curving horizon. A major eruption had begun there. He looked down to the surface over which he was flying — all quiet below — and skipped to the third message.

  Which made up for the other two. It was the answer to Rebka’s own query.

  …A CECROPIAN ANSWERING YOUR DESCRIPTION. SHE IS INTERESTED IN LIFE-FORM EVOLUTION UNDER ENVIRONMENTAL PRESSURE, AS YOU SUGGEST, BUT SHE IS ALSO KNOWN AS A SPECIALIST IN BUILDER TECHNOLOGY…

  …SHE GOES UNDER A VARIETY OF NAMES (AGTIN H’RIF, ARIOJ H’MINEA, ATVAT H’SIAR, AGHAR H’SIMI) AND CHANGES OF EXTERNAL APPEARANCE. SHE MAY BE RECOGNIZABLE BY AN ACCOMPANYING SLAVE INTERPRETER OF THE LO’TFIAN FAMILY. SHE IS DANGEROUS TO BOTH HUMANS AND CECROPIANS, RESPONSIBLE FOR AT LEAST TWELVE DEATHS OF KNOWN INTELLIGENCES AND TWENTY-SEVEN DEATHS OF PROBATED INTELLIGENCE.

  ADDED NOTE: LOUIS NENDA (HUMAN, REPUTED AUGMENTATION), FROM KARELIA IN THE ZARDALU COMMUNION, IS ALSO HEADED FOR DOBELLE. HE IS ACCOMPANIED BY A HYMENOPT SLAVE. NO DETAILS ARE AVAILABLE, BUT THE KARELIA NET SUGGESTS THAT NENDA MAY ALSO BE DANGEROUS.

  NEITHER THE CECROPIAN NOR THE KARELIAN SHOULD BE ADMITTED TO THE DOBELLE SYSTEM…

  Rebka did not throw the printout from the car — it was moving too high and too fast for that. But he did crumple the message and toss it over his shoulder to join the other two. He had spent more than three hours deciphering those missives from Circle headquarters, and all they offered was bad news.

  He lifted his head and stared out of the window ahead. Amaranth was behind him, and the car’s roof shielded its light. He looked west, ready to catch the last gleam of Mandel-set before the primary was lost behind the dark crescent of Quake. The sun’s rim dipped below the horizon.

  His eyes adjusted. And as they did so they picked up a faint, blinking light flashing from a tiny red bead next to the control console. At the same moment an insistent beep started within the cabin.

  Distress circuit.

  The skin on the back of his neck prickled with anticipation. Sixty hours to Summertide. And someone or something, down on the looming dark surface of Quake ahead of him, was in big trouble.

  * * *

  The line of the beacon would bring him down on the fringes of the Thousand Lakes area, not far from the region Max Perry favored for the location of the Carmel twins. Rebka checked the car’s power supply. It was ample — each aircar could make a trip right around Quake and still have something in reserve. No reason for worry there. He sent a brief message to Perry and Graves, then increased the car’s speed and set his new course without waiting for either acknowledgment or approval.

  Mandel was still hidden, but Gargantua was high in the sky and providing enough light to land by. Rebka stared ahead. He was skimming low over a chain of circular lakes, waters steaming and churning. Their turbulent surfaces matched his own mood. Nowhere, from horizon to bleak horizon, was there a sign of life. For that, he would have to look into the waters of the Thousand Lakes themselves, or in the deepest hollows of the Pentacline Depression. Or deeper yet — the most tenacious life-forms would burrow far under Quake’s shifting surface. Would the Carmel twins have had the sense to do the same?

  But maybe he was already too late. The twins were no specialists in harsh-environment survival, and every second the tidal forces at work on the planet below him grew bigger.

  Rebka increased speed again, pushing the car to its limits. There was nothing else he could do. His mind wandered away into troubled speculation.

  Gravity is the weakest force in nature. The strong interaction, the electromagnetic interaction, even the “weak” interaction that governs beta decay, are many orders of magnitude more powerful. Two electrons, one hundred
light-years apart, repel each other with an electric force as great as the attractive gravitational force of two electrons half a millimeter apart.

  But consider the gravitational tidal force. That is weaker yet. It is caused only by a difference of gravitational forces, the difference in the pull on one side of a body from the pull on the other. While gravity is governed by an inverse square law — twice the distance, a quarter the force — gravity tides are governed by an inverse cube law. Twice the distance, one eighth the force; thrice the distance, one twenty-seventh the force.

  Gravity tides should be negligible.

  But they are not. They grip a billion moons around the galaxy, forcing them to present the same face always to their master planets; tides worry endlessly at a world’s interior, squeezing and pulling, releasing geological stresses and changing the figure of the planet with every tidal cycle; and they rip and rend any object that falls into a black hole, so that, no matter how strong the intruder may be, the tides will tear it down to its finest subatomic components.

  For that inverse-cube distance relationship can easily be inverted: one half the distance, eight times the tidal force; one third the distance, twenty-seven times the tidal force; one tenth the distance…

  At closest approach to Mandel, the Dobelle system was one eleventh of its mean distance from the primary. One thousand three hundred and thirty-one times the mean tidal force was exerted upon its components.

  That was Summertide.

  Hans Rebka had been told those basic facts by Max Perry, and he thought of them as he overflew the surface of Quake. Every four hours, the vast invisible hand of Mandel and Amaranth’s gravity squeezed and pulled at Opal and Quake, trying to turn their near-spherical shapes into longer ellipsoids. And close to Summertide, tidal energy equivalent to a dozen full-scale nuclear wars was pumped into the system — not just once, but twice every Dobelle day.

  Rebka had visited worlds where global nuclear war had recently taken place. Based on that experience he expected to see a planet whose whole surface was in turmoil, a seething chaos where the existence of life was impossible.