Fate of Worlds: Return From the Ringworld

by Larry Niven

  “Doubtless, some humans,” Chiron sang. “Let Nessus recruit his own team.”

  “The New Terrans no longer serve us,” Hindmost gently reminded. “We are no longer welcome on their world.”

  “Wild humans,” Chiron clarified. Several ministers started at the petulant grace notes in his song. “Nessus can recruit on Earth.”

  “Earth is too distant,” Zephyrus sang. “Sooner than Nessus can reach Earth, the Fleet must already have encountered the Ringworld.”

  “Not if Nessus takes Long Shot,” Chiron rebutted.

  With renewed forebodings of disaster, without options, Hindmost once more concurred.

  Earth Date: 2893

  With a shiver of dismay, Hindmost turned from his mirror.

  So many years. So much travail. Only to find himself on this ill-fated ship! He at best half understood normal hyperdrive, a level of insight that made him more knowledgeable than most. The Outsiders priced their technology and the underlying theory separately — and the technology was costly enough.

  But somehow, just once, inspired (and demented) tinkerers in General Products Laboratories had created what they called the Type II drive. The Type II hyperdrive shunt was huge: the largest hull that General Products built, a sphere more than a thousand feet in diameter, could barely contain the apparatus.

  After years of hideously expensive research had failed to duplicate the initial prototype, General Products Corporation was no closer to understanding why this particular hyperdrive flung this particular ship through hyperspace thousands of times faster than any other. The Outsiders, when Concordance engineers approached them, had expressed no opinions and declined to participate in any research. No one knew why, but no one understood why the Outsiders did most things. Creatures of liquid helium, the Outsiders were, simply, different.

  General Products was on the verge, reluctantly, of halting their futile research program when inspiration struck.

  From Hearth’s ancient place of hiding, the Concordance did business in that era with a half-dozen alien trading partners. With some grand demonstration, some spectacular publicity stunt, General Products thought to lure alien investors into underwriting continued experimentation. They jammed every nook and cranny of the prototype with extraneous equipment to mask the ad hoc nature of the only working Type II drive. They recruited a human pilot to fly the ship he named Long Shot all the way to the galactic core.

  Of such convoluted origins comes disaster.

  Except for Beowulf Shaeffer’s flight, the chain reaction of supernovae among the close-packed stars of the core would have gone undiscovered. A dangerous thing not to know, to be sure. But better to be ignorant of a peril many millennia into the future than to evoke immediate catastrophe.

  Except for Long Shot and Shaeffer’s discovery, the Fleet would never have cast off its gravitational anchor from Giver of Life, its ancestral star.

  Except for Hearth’s sudden, unplanned sprint from the galaxy, Citizens would never have trained their human servants to explore in the Fleet’s path. Their humans would never have uncovered their true past. Nature Preserve Four would still be one among the farm worlds serving the Concordance.

  Except for scouting ahead in the Fleet’s hastily chosen path, the Gw’oth would have remained unknown to this day.

  And yet …

  Had the Gw’oth not spotted the refugees running from the core explosion, had the Gw’oth not contacted newly independent New Terra, Pak war fleets would have caught everyone unawares, would have pounded all their worlds, Hearth included, back into the Stone Age.

  Hindmost plucked loose a tress he had just tucked into place. It seemed every course of action led to disaster.

  Now he rode the ship that, from Beowulf Shaeffer’s era until Ol’t’ro’s covert reign, none had dared to fly. The ship on which Ol’t’ro had demanded the Concordance dedicate its wealth and best scientists, in vain hopes that the technology would be mastered.

  And yet it was worth the price, any price, to divert Ol’t’ro from wondering if the time had come to pull the doomsday trigger. Every Hindmost had complied willingly.

  Then Ol’t’ro had ordered Nessus to Earth. Aboard any normal vessel, even then, that would have been a trek of almost two years. On Long Shot, the trip was a matter of a few hours. Nessus had recruited two humans and a Kzinti diplomat for the “first” Ringworld expedition, bartering Long Shot itself as their payment.

  Humans and Kzinti could waste lives and treasure trying to duplicate the Type II drive. Hindmost remembered his relief that the ill-fated ship was gone.

  Only to find, long after, while stranded on the Ringworld by his own foolhardy misadventure, that Long Shot had returned! Kzinti had usurped the fastest ship in existence, using it as a courier to coordinate their part of the interspecies mayhem Hindmost knew as the Fringe War. Until Tunesmith seized Long Shot from the Kzinti. Until Louis and Hindmost took it from Tunesmith, because the protector chose to be rid of them.

  And here I am aboard Long Shot. After … how long?

  “Voice,” he called.

  Notes tinkled from a nearby intercom speaker. “Yes, Hindmost.”

  “Do onboard computers indicate the current date?”

  “They do, although not using the Concordance calendar.”

  “The human calendar will serve.”

  “The Earth date is 2893, Hindmost.”

  Much as he had expected — but suddenly, so terribly real. He had fled Hearth in 2860. Thirty-three years ago! Thirty-seven years as reckoned on Hearth, except that in the Fleet, rushing northward out of the galaxy at eight-tenths light speed, clocks ticked a third slower.

  By any measure, and in every frame of reference, too long.

  He looked himself in the eyes. All those years gone forever, and for what?

  “Have I ever explained why I brought us to the Ringworld?”

  “No, Hindmost.”

  As he had thought. One does not justify oneself to one’s tools. But when only a tool stands between oneself and catatonia …

  He left his cabin to canter once more around this accursed ship. The AI would track and hear him through hallway sensors, would continue the dialogue through any convenient intercom speaker. “I came for technology. The Ringworld must have had, the Ringworld embodied extraordinary technologies. It did not matter that the Ringworlders themselves had forgotten.”

  Technology he meant to trade. No matter the depth of his loneliness, with whom he must negotiate went unstated. Some burdens only a Hindmost can bear.

  “And did you find what you sought, Hindmost?”

  To this day, he believed that the Ringworld foundation material, the wondrously robust stuff the natives called scrith, could only have been manufactured through some industrial-scale process of transmutation. That was the magic he had sought, the enticement for Ol’t’ro, the treasure with which he had hoped to buy freedom for Hearth. The technology of which he had gotten not as much as a glimpse in his years on the Ringworld.

  “Not even close.” Hindmost rounded a corner —

  And froze.

  He did have Long Shot with Tunesmith’s improvements. Louis had jumped it to hyperspace from within the singularity that was the Ringworld, which itself was within the singularity of the nearby star — and despite all theory and experience, the ship had come back out. He had clues painstakingly collected to the operation of Ringworld-become-hyperdrive, imprinted in its obscenely powerful gravity wave.

  After much anguished deliberation, the outline of a new hyperspace physics had begun to take shape in Hindmost’s mind.

  When Louis emerged from the autodoc, hopefully still able to pilot this ship, perhaps they could use that knowledge.

  8

  A very thin line encircled the bridge: short navy-blue dashes alternating with longer pale blue dashes.

  The Ringworld.

  Or, rather, Endurance having exited hyperspace sixty light-days from its destination, the Ringworld as it had appeared s
ixty days earlier.

  Alice stood at the center of the bridge, turning slowly, trying to take it in. Her view was from above the plane of the Ringworld, and she could see … everything. She just couldn’t wrap her mind around what she saw.

  Six hundred million miles in circumference. It was an expanse beyond comprehension, so she tried changing scales. About sixty feet around the bridge. Each foot of image along the wall represented … six million miles. Still unreal. Call it 830,000 miles — more than thirty times around New Terra — to the inch!

  “I wish you luck,” Nessus said, his voice quavering. He sat astraddle the pilot’s couch, looking uncomfortable. He had offered to pilot so that Julia could concentrate on observing. He had seen it before.

  Left unstated: who better to be ready to run?

  “What do you mean, Nessus?” Alice asked.

  He looked himself in the eyes. “You wish to grasp the scale of the thing. I never succeeded.”

  Julia walked up to the wall and with her thumb covered a bit of the loop. “The width of my thumb? It’s almost a million miles! Walk fifty miles a day, and you couldn’t cross the width of that place in fifty years.”

  A hoof scraped at the deck, but Nessus said nothing. With one head he stared at the main sensor panel; with the other he watched the panorama streaming in an auxiliary display: the Ringworld, spinning in place beneath their telescope, simulating a flyover.

  Alice watched terrain undulate past at an almost hypnotic pace. Hills. Lakes. Grassy plains. Forests. A sea. Make that an ocean. A big ocean.

  “Any signs of civilization?” Alice asked.

  “Not yet,” Nessus said, “except for the structure as a whole, of course.”

  Julia said, “How long until — ”

  “Wait! Back up.” Something in the flyover had caught Alice’s eye. Something familiar. But what here could be familiar?

  The close-up stopped and then retraced its path. And there, little more than a speck in that vast ocean, what had caught her eye: a patch like a flattened map of Earth! Nearby was a reddish disk that could be Mars. More disks, unfamiliar to her, lay scattered nearby. Other worlds?

  “The world models are full-sized,” Nessus said. “No, I can’t explain them.”

  Julia had never seen Earth or Mars. No native New Terran had. She asked, “How long until light from the anomaly itself reaches us?”

  Nessus glanced at a timer running on his console. “Call it five minutes.”

  At two, he banished the simulated-flyover view, turning an eye back to the wall and its view of the ring. “It’s coming up,” he said. “Five seconds. Four…”

  At zero, from almost a trillion miles away, they saw the Ringworld — disappear.

  * * *

  UNIFORMED ESCORTS HUSTLED SIGMUND through the corridors of the Ministry of Defense, past closed doors and hushed but intense hallway conversations. Something was going on, and it had not just begun. There had been time for rumors, if not yet actual news, to run rampant through the building.

  Since Julia’s departure, he had carried his pocket comp at all times. He had kept the stepping disc at home right-side up. That he hadn’t been contacted the moment … whatever happened was someone’s deliberate choice.

  He did not think he was being paranoid.

  Knowing Julia, she had kept her normal-space sanity breaks to a minimum. Endurance might have reached its destination.

  Was that why he had been summoned?

  In the situation room, too crowded for his taste, Sigmund found a meeting already in progress. The bridge of Endurance occupied the room’s main holo display. The crew looked weary but unharmed, and Sigmund breathed a little easier.

  He took a chair at the main table next to one of the more helpful, less doctrinaire deputy ministers. Corinne somebody. Age had not improved his problem remembering names.

  “Here.” Corinne tapped the personal display inset in front of Sigmund. “The real-time feed so far for the link.”

  “Thanks.” He fast-forwarded through the recording, skimmed the transcript. Much of the session had gone to waiting for light to crawl to and from the hyperwave relay at the edge of New Terra’s singularity. He hadn’t missed much.

  Except for the Ringworld disappearing.

  An inner band, rapidly spinning, had remained behind. Even at full magnification it looked like co-orbiting panels, but Nessus’ Ringworld expedition had found that invisibly thin wires held the panels together.

  Shadow squares, Nessus had called the structure. Without the shadows it cast, Ringworlders would have lived in unending day. Compared to the Ringworld itself, the shadow-square band looked flimsy — only it, too, must be incredibly robust or centrifugal force would have torn it apart. Clever, but Sigmund was more interested in the other technology purportedly on the shadow squares: solar power plants and vast numbers of sensors.

  “… Thorough survey, across the spectrum,” Minister Norquist-Ng was saying. “Our scientists have proposed several theories, and we’ll want to give them — ”

  “Excuse me, Minister.” Sigmund turned to address the camera. “I have to ask something time-sensitive. Who else came to investigate this phenomenon?” Are the three of them safe?

  The light-speed delay to and from the hyperwave relay gave Norquist-Ng plenty of time to frown.

  “You’re right, Sigmund, we have company,” Alice said. “Lots of ships, to judge from hyperspace ripples and comm chatter. But the comm is unintelligible, whether alien or just encrypted. Our Jeeves hasn’t yet had any luck with it.

  “Having said that, everything we’ve intercepted, radio and hyperwave, is faint. I doubt we have anyone nearby.”

  “Near being a relative term,” Sigmund said.

  A minute and a half later — time enough, through hyperdrive, for any of the nearby ships to travel two light-days! — he saw Alice’s answering shrug.

  Nessus turned a head toward the camera. “I keep us moving, a short hyperdrive jump every few minutes. In fact, if you’ll excuse us — ”

  The holo froze for several seconds. When motion returned to the real-time feed, Nessus was giving his full attention to his instruments.

  “Very well, Mr. Ausfaller,” Norquist-Ng said. “As I was saying — ”

  Those ships. Might they be from Human Space? After so long, could the path be open back to Earth? But for what peaceful reason would anyone send so many ships? And if not peaceful, then …

  “Whose ships are they, Nessus?” Sigmund interrupted again.

  “We would need to get much closer to tell,” Nessus said, as with his other head he tugged and twisted at his mane. Clearly, he did not want to get closer. That might be only typical Puppeteer risk avoidance.

  Or Nessus might hesitate lest Alice and Julia find an ARM ship to contact.

  “Are you finished, Ausfaller?” Norquist-Ng asked. “We sent a ship to scope out an unprecedented event. It seems other worlds did, too. With reasonable precautions, I think we can avoid any — ”

  Ostriches! Sigmund thought. Did isolation ever not backfire?

  But Julia was also speaking. “… May … Ringworld left … one-light-hour hops…”

  “Jeeves, back us up to the start of the captain’s last comment,” Sigmund directed.

  “Yes, sir,” the conference-room AI said.

  “We may have data on why the Ringworld left. We backed off several light-days in one-light-hour hops, hoping to see what led up to the departure. What we observed, scattered around and sometimes on the Ringworld, were gamma-ray bursts, some powerful.”

  “So, gamma-ray bursts,” someone muttered from the back of the room. “The skies are full of them.”

  “Not around planets,” Norquist-Ng barked at the hapless aide. “Ausfaller. Any ideas?”

  “Antimatter,” Sigmund said. “The most powerful explosive imaginable. When matter and antimatter meet, all that’s left from the encounter is gamma rays.

  “Someone was fighting over the Ringworld, and we’ve sen
t our people into the war zone.”

  9

  As Alice and Julia kept trying to bring a halt to the interminable consultation with New Terra, Nessus focused on piloting their ship. Warships armed with antimatter! Against antimatter, twing would be like tissue. Not even a General Products hull could withstand an antimatter bullet. No wonder the Ringworld — however the trick had been done! — had fled.

  And good riddance.

  Had he not been certain that the humans would wrest back control, he would already have started Endurance on its way to … anyplace but here.

  Instead, every few minutes Nessus jumped the ship around the chaos. The task required surprising concentration. Although Jeeves could have proposed jump timing, the algorithm the AI used to simulate randomness might have been familiar to ARM ships executing the same algorithms. He could not imagine them predicting this pattern.

  Earth finding the Fleet? That had come to serve his purposes. Earth discovering the ancient crime by which New Terra had been settled? That was a complication and a risk he had spent much of his life trying to prevent.

  (Alice had recognized the map of Earth! She had tried to cover her slip, not said what caught her eye, but he knew. He had long suspected she was from outside. But wherever Alice was from, however she had come to be on New Terra — Sigmund, too, kept secrets — if she could have guided a ship back to Earth, it would have happened by now.)

  “Could Endurance be spotted?” someone on New Terra asked.

  “We’re stealthed, but that goes only so far,” Julia said. “We can’t avoid giving off heat, so infrared sensors might see us. Our power plant sprays neutrinos. And ships detecting this broadcast might be trying to track us down.”

  “Let’s review calibrations on your passive sensors,” someone said, missing or ignoring Julia’s hint.

  “Another jump,” Nessus announced, his heads shaking. Julia or Alice would have to take his place soon.