Convergent Series Page 4

  The stars of the Circle lay in a region overlapped by all three major clades of the spiral arm. But in their outward expansions the Fourth Alliance, the Zardalu Communion, and the Cecropia Federation had shown negligible interest in the Phemus Circle. There was nothing there worth buying, bargaining for, or stealing—hardly enough to justify a visit.

  Unless one was looking for trouble. Trouble was supposed to be easy to find on any world controlled by the Circle.

  Darya Lang stepped out of the ship onto the spongy ground of Opal's Starside spaceport and looked around her with misgiving. The buildings were low and ground-hugging, built of what looked like plaited reeds and dried mud. No one was waiting to greet the ship. Opal was described as metal-poor, wood-poor, and people-poor. All it had was water, and lots of it.

  As her shoe sank an inch or two into the soft surface she felt even more uneasy. She had never visited a waterworld, and she knew that instead of hard rock and solid ground beneath her feet, there was only the weak and insubstantial crust of the Sling. Below that was nothing but brackish water, a couple of kilometers deep. The buildings hugged the ground for a good reason. If they were too tall and heavy, they would break through it.

  An irrelevant thought came to her: she could not even swim.

  The crew of the ship that had brought her were still involved with the final stages of landing procedure. She began to walk toward the nearest building. Two men were finally emerging from it to greet her.

  It was not a promising introduction to Opal. Both men were short and thin—Darya Lang was ten centimeters taller than either of them. They were dressed in identical dingy uniforms, with clothes that shared a patched and well-worn look, and from a distance the two might have been taken for brothers, one ten years or so older than the other. Only as she came closer were their differences revealed.

  The older man had a friendly, matter-of-fact air to him and a self-confident walk. The faded captain's insignia on his shoulder indicated that he was the senior of the two in rank as well as age. "Darya Lang?" he said as soon as they were within easy speaking distance. He smiled and held out his hand, but not to shake hers. "I'll take your entry forms. I'm Captain Rebka."

  Add "brusque" to the list of words describing the inhabitants of the Phemus Circle, she thought. And add "unkempt" and "battered" to Rebka's physical description. The man's face had a dozen scars on it, the most noticeable running in a double line from his left temple to the point of his jaw. And yet the overall effect was not unpleasant—rather the opposite. To her surprise, Darya sensed the indefinable tingle of mutual attraction.

  She handed over her papers and made internal excuses for the scars and the grimy uniform. Dirt was only superficial, and maybe Rebka had been through some exceptional misfortune.

  Except that the younger man looked just as dirty, and he had his own scars. At some time his neck and one side of his face had been badly burned, with a bungled attempt at reconstructive surgery that would never have been accepted back on Sentinel Gate.

  Maybe the burn scars had also left the skin of his face lacking in flexibility. Certainly he had a very different expression from Rebka. Where the captain was breezy in manner and likeable despite his grubbiness and lack of finesse, the other man seemed withdrawn and distant. His face was stiff and expressionless, and he hardly seemed aware of Darya, although she was standing less than two meters from him. And whereas Rebka was clearly in top physical shape, the other had a run-down and unhealthy look, the air of a man who did not eat regular meals or care at all about his own health.

  His eyes were at variance with his young face. Dead and disinterested, they were the pale orbs of a man who had withdrawn from the whole universe. He was unlikely to cause Darya any trouble.

  Just as she reached that comforting conclusion the face before came alive and the man snapped out, "My name is Perry. Commander Maxwell Perry. Why do you want to visit Quake?"

  The question destroyed her composure completely. Coming without the preliminary and traditional courtesies of Alliance introductions, it convinced Darya Lang that these people knew—knew about the anomaly, knew about her role in discovering it, and knew what she was there to seek. She felt her face turning red.

  "The—the Umbilical." She had to struggle to find words. "I—I have made a special study of Builder artifacts; it has been my life's work." She paused and cleared her throat. "I have read all that I could find about the Umbilical. But I want to see it for myself and learn how the tethers work on Opal and Quake. And discover how Midway Station controls the Umbilical for the move to space at Summertide." She ran out of breath.

  Perry remained expressionless, but Captain Rebka had a little smile on his face. She was sure that he saw right through her every word.

  "Professor Lang." He was reading from her entry papers. "We do not discourage visitors. Dobelle needs all the revenue it can get. But this is a dangerous time of year on Opal and Quake."

  "I know. I have read about the sea tides on Opal, and the land tides on Quake." She cleared her throat again. "It is not my nature to seek danger." That at least was true, she thought wryly. "I propose to be very careful and take all precautions."

  "So you have read about Summertide." Perry turned to Rebka, and Darya Lang detected a tension between the two men. "As have you, Captain Rebka. But reading and experiencing something are not the same. And neither of you seems to realize that Summertide this time will be different from all others in our experience."

  "Every time must be different," Rebka said calmly. He was smiling, but Darya Lang could feel the conflict. Rebka was the older and the more senior, but on the issue of Summertide Commander Perry did not accept the other's authority.

  "This is exceptional," Perry replied. "We will be taking extraordinary precautions, even on Opal. And as for what may happen on Quake, I cannot begin to guess."

  "Even though you have experienced half a dozen Summertides?"

  Rebka had lost his smile. The two men faced each other in silence, while Darya looked on. She sensed that the fate of her own mission hung on the argument that they were having.

  "The Grand Conjunction," Perry said after a few seconds. And finally Darya had a statement that made sense to her as a scientist.

  She had studied the orbital geometry of the Mandel system in detail while working on the Lang catalog of artifacts. She knew that Amaranth, the dwarf companion of Mandel, normally moved so far from the primary that the illumination it provided to Dobelle was little more than starlight. However, once every few thousand years its motion brought it much closer, to less than a billion kilometers of Mandel. Gargantua, the remaining gas-giant planet of the system, moved in the same orbital plane, and it, too, had its own point of close approach to Mandel.

  Dobelle's critical time of Summertide usually occurred when Gargantua and Amaranth were both far from Mandel. But all three orbits were in resonance lock. On rare occasions, Amaranth and Gargantua swung in together to Mandel, at a time that coincided with Summertide for Opal and Quake. And then . . .

  "The Grand Conjunction," Perry repeated. "When everything lines up at periastron, and the sea tides and land tides on Opal and Quake are as big as they can possibly be. We have no idea how big. The Grand Conjunction happens only once every three hundred and fifty thousand years. The last time was long before humans settled Dobelle. But the next time will happen just thirty-three days from now—less than two standard weeks. No one knows what Summertide will do to Opal and Quake then, but I do know that the tidal forces will be devastating."

  Darya looked at the soft ground beneath their feet. She had the terrible feeling that the flimsy mud-raft of living and dead plants was already crumbling under the assault of monstrous tides. No matter what the dangers might be on Quake, surely they were preferable to staying on Opal.

  "So wouldn't you all be safer on Quake?" she asked.

  Perry shook his head. "The permanent population of Opal is more than a million people. That may seem like nothing for someone like yo
u, from an Alliance world. But it is a lot for a Circle world. My birth planet had less than a quarter of that."

  "And mine less than an eighth of it," Rebka said mildly. No one stayed on Teufel who had any way to get off it.

  "But do you know the permanent population of Quake?" Perry glared at both of them while Lang wondered how she had ever thought him calm and passionless.

  "It is zero," he said after a pause. "Zero! What does that tell you about life on Quake?"

  "But there is life on Quake." She had studied the planetary index. "Permanent life."

  "There is. But it is not human life, and it could not be. It is native life. No human could survive Quake during Summertide—even a normal Summertide."

  Perry was becoming increasingly assertive. Darya knew that her case for visiting Quake was lost. He would deny her access, and she would get no closer to Quake than the Starside spaceport. As she decided that, help came from an unexpected direction.

  Rebka turned to Max Perry and pointed a thin finger up to Opal's cloudy skies. "You are probably right, Commander Perry," he said quietly. "But suppose strangers are coming to Dobelle because it will be the Grand Conjunction? We did not consider that possibility when we were examining their applications." He turned to stare at Darya Lang. "Is that your real reason for being here?"

  "No. Definitely not." She felt relief at being able to give an honest answer. "I never thought about the Conjunction until Commander Perry mentioned it."

  "I believe you." Rebka smiled, and she was suddenly convinced that he did. But she recalled Legate Pereira's words: "Don't trust anyone from the Phemus Circle. They practice survival skills that we in the Alliance have never been forced to learn."

  "People's reasons for coming here are not too relevant, of course," he went on. "They don't make Quake any safer." He turned to Perry. "And I feel sure you are right about the dangers of Quake at Summertide. On the other hand, I have a responsibility to maximize the revenues of Dobelle. That's my job. We have no responsibility to protect visitors, beyond a duty to warn them. If they choose to proceed, knowing the risks, that is their option. They are not children."

  "They have no notion of what Quake is like at Summertide." Perry's face had turned blotchy white and red. He was overwhelmed by strong emotion. "You have no idea."

  "Not yet. But I will have." Rebka's manner changed again. He became a boss who was clearly giving orders. "I agree with you, Commander. It would be irresponsible for Professor Lang to visit Quake—until we are sure of the hazards. But once we do understand them—and can explain them—we have no duty to be overprotective. So you and I will go to Quake, while Professor Lang remains here on Opal."

  He turned to Darya. "And when we return . . . well, then, Professor Lang, I will make my decision."

  ARTIFACT: SENTINEL

  UAC#: 863

  Galactic Coordinates: 27,712.863/16,311.031/761.157

  Name: Sentinel Star/planet association: Ryders-M/Sentinel Gate

  Bose Access Node: G-232 Estimated age: 5.64 ± 0.07 Megayears

  Exploration History: Sentinel was discovered in Expansion Year 2649 by human colonists of the trans-Orionic region. First entry attempt, E. 2674, by Bernardo Gullemas and the crew of exploration vessel D-33 of Cyclops class. No survivors. Subsequent approaches attempted E. 2682, E. 2695, E. 2755, E. 2803, E. 2991. No survivors.

  Sentinel warning beacon set in place, E.2739; monitoring station established on nearest planet (Sentinel Gate), E. 2762.

  Physical Description: Sentinel is a near-spherical inaccessible region, a little less than one million kilometers across. No visible internal energey sources, but Sentinel glows faintly with its own light (absolute magnitude +25) and is visible from every point of the Ryders-M system. The impassable surface of Sentinel readily permits two-way passage of light and radiation of any wavelength, but it reflects all material objects including atomic and subatomic particles. There is photon flux only from the interior, with no particle emission. Laser illumination of the interior is possible, and reveals a variety of structures at the center of the sphere. The most prominent such feature is "The Pyramid," a regular tetrahedral structure which absorbs all light falling onto it. If interior distances within Sentinel have meaning (there is evidence that they do not—see below) then the Pyramid would be approximately ninety kilometers on a side. No increase in temperature of the Pyramid is detectible, even when incident absorbed radiation is at the gigawatt level.

  Path length measurements using lasers show that rhe interior of Sentinel is not simply-connected; minimal light travel time across Sentinel is 4.221 minutes, compared with a geodesic travel time of 3.274 seconds for equivalent distance across empty space remote from matter. For light incident normally on the Sentinel "equator" travel times across Sentinel are infinite, or certainly in excess of a thousand years. Red shift and grazing incidence laser beams indicate that no mass is present within Sentinel, a result that is inconsistent with the observed interior structure.

  Sentinel holds a precise distance of 22.34a.u. from the Ryders-M primary star, but is not in orbit about it. Gravitational forces and radiation pressure forces either are exactly compensated by some unknown mechanism in Sentinel, or do not act on the structure at all.

  Physical Nature of Sentinel: According to Wollaski'i and Drews, Sentinel takes advantage of and is built around a natural anomaly of space-time and possesses only weak physical coupling to the rest of the universe. If so, this is one of only thirty-two Builder artifacts that were created with the use of preexisting and natural features.

  Sentinel topology appears to be that of a Ricci-Cartan-Penrose knot in 7-space.

  Intended Purpose: Unknown. However, it is conjectured (by analogy with other Builder artifacts, see Entry 311, 465, and 1223) that the Pyramid may possess near-infinite information storage capacity and lifetime. It has therefore been suggested (Lang, E. 4130) that the Pyramid and possibly the whole of Sentinel form a Builder library.

  —From the Lang Universal Artifact Catalog, Fourth Edition.

  CHAPTER 4

  Summertide

  minus thirty-one.

  The first part of the flight to Quake was conducted in total silence. Once it was clear that Hans Rebka was insistent on going and could not be dissuaded, all Perry's energy had vanished. He sank into a strange lethargy, sitting at Rebka's side in the aircar and staring straight ahead. He roused briefly when they came to the foot of the Umbilical, but only long enough to lead the way to a passenger capsule and initiate the command sequence for ascent.

  Seen from sea level the Umbilical was impressive but not overwhelming. It appeared to Rebka as a tall slender tower of uniform thickness, maybe forty meters across, stretching from the surface of Opal's ocean at the lower end up into the thick and uniform cloud layer. The main trunk of the structure was a silvery alloy, up and down which passengers and cargo could move in huge cars. The attachments were electromagnetic, held and driven by linear synchronous motors. The detailed design might be unfamiliar, but Rebka had seen the concept used on a dozen worlds, carrying people and materials up and down multikilometer buildings, or high into orbit. The knowledge that there were over two kilometers more of the Umbilical below sea level, reaching down to a tether on the ocean floor, was more surprising, but the mind could accept it.

  What the mind—or Rebka's mind at least—could not so readily accept was the twelve thousand kilometers of the Umbilical above the clouds, reaching all the way from Opal to Quake's parched and turbulent surface. The observer who climbed into a capsule was seeing less than one ten-thousandth of the whole structure. With a maximum free-space car speed of a thousand kilometers an hour, travelers would expect to see two sunrises on Quake before they got there.

  And now they were on their way.

  The capsule was as tall and broad as Opal's biggest buildings. As the Builders had left it, the inside was one large empty space. Humans had added interior floors, from a massive cargo hold at the bottom to the control-and-observation c
hamber at the top.

  The car's motors were silent. All that could be heard as they rose smoothly through the cloud layer was a whistle of air and the mutter of atmospheric turbulence. Five seconds more, and Hans Rebka had his first view of Quake as seen from Opal. He heard Max Perry grunt at his side.

  Maybe Rebka grunted, too. For Opal's permanent cloud layer suddenly seemed like a blessing. He was glad that the other planet had been hidden when he had been down on Opal's surface.

  Quake stood huge in the sky, a sunlit, mottled ball that was poised and ready to crash down onto him. His hindbrain told him that no force in the universe could hold such a weight, that one would never become used to the sight. At the same time his forebrain did a calculation of orbital rates and the matching of centrifugal and gravitational forces, and assured him that everything was in perfect dynamic balance. People might be uncomfortable with the threat of Quake overhead for a day or two; then they would get used to it and ignore it.

  From this distance no details were visible, but it was clear that he was looking at a world without major seas and oceans. Rebka thought at once of terraforming; not just Quake or Opal, but of the doublet together. It was the perfect application. Quake had the metals and minerals; Opal had the water. It would be a substantial task, but no bigger than others he had undertaken. And the beginning of the necessary transportation system was already in position.

  He looked along the thread of the Umbilical. The line upward was visible for perhaps a hundred kilometers before he lost it. Midway Station, four thousand kilometers above them at the center of mass of the Opal-Quake system, could be seen as a tiny golden knot on an invisible thread. They would be there for changeover in half a day. Plenty of time to think.