When Max came out into the golden light of late afternoon, a pedal glider was moving down the long, zerogravity axis of the hollow, the space around which the habitat turned to give the inner surface and levels below a centrifugal gravity.

  This was the only home he had ever known. It was carrying fifteen hundred and seven people back to what the adults called home, to the star called the Sun, to the family of planets and habitats of which Earth was the parent. Arrival time was now only two months away, and there was nothing he could do to change the scheduled return to the civilization that had launched his world across the 4.3 light-years to Alpha Centauri. The return would complete a great adventure, his parents had always told him.

  Maybe it was the idea of there being so many billions of people on Earth, the Moon, Mars, and elsewhere in Sunspace that made him unhappy about leaving the habitat. Humankind was much larger than the portion he had grown up with. There were only a hundred and four kids in the returning habitat. On Earth there would be people he had never met, and would never meet. He had seen many people in the library holos, and had listened to their lectures and watched their behavior in old films, but he had never quite believed that so many people could all be different from one another. With thousands of millions, too many would be alike. It seemed strange and unnecessary to have so many, nearly twenty billion throughout Earth’s Sunspace.

  “Should we have raised children?” he had once overheard his mother say. “I sometimes wonder. You know what some are saying—that we’ve brought up a bunch of self-centered kids without a lot of social skills who won’t ever fit in back home.”

  “I’ve heard it, Rosalie,” his father had answered. “Those people are the ones who didn’t have kids.”

  “Maybe we were selfish, Joe,” she had continued, “telling ourselves that having children would make our journey more normal. We wouldn’t feel so alone as a community all these years. I worry that we had these children for ourselves only. What if we’ve spoiled them for any kind of life back home?”

  “Oh, I don’t think so,” Joe had said.

  “Max has never known anything but this protected world,” Rosalie had objected.

  “He’ll learn and adapt, I’m sure.”

  Max went down the library path and strolled between the tall maple trees until he came out on the road that led up the habitat to his house. The sunplate was warm on his back as he walked toward the rocky forward end of the world. After a few minutes he slowed his pace, still feeling resentful. His parents had always talked of “going home”; but they had lived on Earth, so abandoning the habitat could never mean as much to them. He imagined it in orbit around a crowded Earth, empty and waiting to be torn apart, or used for some other purpose. Everything he had known would be gone, and the Earth would swallow him.

  A chill passed through him as he turned around and gazed at the beauty of sunplate and green hollow, then closed his eyes and felt every part of the habitat within himself. The original asteroid had been five kilometers long. Its open space, four kilometers long and two across, had been cut out of the core. Just outside the hollow there was an engineering level, and beyond that hundreds of meters of rock and nickel-iron protected the inner world from the dangers of space. Rotation gave the inner surfaces nearly one Earth gravity. It wasn’t the same as gravity on a planet, where the large mass exerted its own pull; centrifugal gravity was the same action that held water down at the bottom of a bucket spinning at the end of a line. There were dangers in walking around on a surface where your head pointed toward the center of the world and the stars were outside, under your feet, and if you jumped too high you might not come down where you wanted; but he was used to it, and felt pride in understanding his world.

  He left the road and climbed the grassy hillside. Halfway up he lay down on his back and gazed up at the land two kilometers overhead. It was always a wonder to him that this peaceful scene of green countryside, roads, paths, and houses was moving through space at a speed that he understood but could not imagine. The vast power output of the matter-antimatter reactors went into the null-gravity field, whose gentle but continuous push made it possible for his habitat to attain the high fraction of light speed needed to reach the nearer stars in a reasonable time, and to do so in relative safety and comfort. Earth was readying other habitats to voyage to still farther stars. Slowly, humankind would spread outward into this spiral arm of the galaxy.

  Max did not remember the arrival at Alpha Centauri. He had been born just as exploration of that system was beginning, and his earliest memory was of Centauri A, the yellow sun of the triple star system, and its fourth planet, where for the first time he had seen oceans and green continents, all on the outside of a world so much larger than his own. The sight from space had frightened him at first.

  His parents had taken him on a field trip with some of the other children, so they would see something of the alien system before departure. “They should have a memory of this place,” his mother had said. Max remembered the colors of the three suns. Rocky moons circled the dead worlds of the small red sun. The dim white sun seemed lonely. Centauri A resembled Earth’s Sun, his father had told him.

  Lucian “Lucky” Russell, a planetary specialist, had piloted the shuttle, and had given a lecture about its systems at the end of the two-week trip. By the time Max was seven years old, a new habitat was being built in high orbit around Centauri A-4. Five hundred people had settled inside the second hollow. It would explore and carry on research in the Centauri system while the first habitat went home.

  The trip from Earth had taken nearly ten years. Allowing seven years for exploration at Centauri, time for acceleration, deceleration and maneuvering, and another decade for the return, some twenty-seven years had passed since the habitat left Earth’s Sunspace. Joe Sorby and Rosalie Allport, Max’s parents, were twenty-seven years older, but their friends back home had aged nearly thirty-six years, because at two-thirds of light speed, time on the habitat passed more slowly than it did for people on Earth.

  “We’ll try for a higher velocity on the way back,” his father had told him. “We’ll get back sooner, from our point of view, but even more time will have passed on Earth.” Max had not understood all this too well at age seven, but at sixteen Einstein’s Time Contraction Theory was no longer a mystery; it seemed only natural that fast-moving clocks ran slower in comparison to clocks left behind. This was true not only of mechanical clocks, but also of biological clocks like his body. The habitat’s return would be quicker at eighty percent of light speed, but the price would be arrival farther in Earth’s future, so the final decision had been to return at two-thirds of light speed, not only to avoid the psychological problems of a larger dislocation in time, but also to save wear and tear on the habitat from high-speed collisions with interstellar gas and dust. At speeds closer to that of light, even the smallest particle would strike the habitat with enormous force, so even more energy would be needed for the deflection shield.

  Max didn’t care if he arrived farther in Earth’s future; he had nothing to lose, since he had never seen Earth and knew no one there. People who had been the same age as his parents would now be older. That was interesting, but for him the only thing that mattered was that he would lose his home and have to face a strange new world. The people of the habitat would disperse to places on Earth, the Moon and Mars, to other habitats, going wherever their work took them.

  He had never quite believed that it would happen. His next-door neighbors, Leni and Arthur Cheney, would move away, and he might never see them again. Max smiled bitterly; he would even prefer to put up with Arthur, who had bullied him when they were younger and now settled for getting off an occasional sarcastic remark when his sister Leni wasn’t around to restrain him. Once, he had wished that Arthur would be sucked out of an airlock, never to be seen again; now he was already starting to miss the creep. It was like thinking about dying, or trying to remember the time when he couldn’t read or do math. People lived well past a century, but sooner or later death would come. He could not imagine dying, and he had never worried about the return to Earth until this year, but here it was, coming closer every minute.

  He sat up in the grass, feeling a bit warm. The sunplate was dimming now, glowing orange as the afternoon faded. He felt a slight breeze on his face. Filmy clouds appeared in the great open space, drifting across the houses on the other side of the world. Max lay back again and closed his eyes, trying to regain his feelings of happiness and unconcern for the future. He breathed deeply, then opened his eyes to the yellow flowers near him, pushing away the image in his mind of a rocky nickel-iron asteroid decelerating toward a Sunspace that he would never be able to accept as home.

  He got up suddenly and hurried down the hillside. He passed the elevator kiosk at the crossroads just as Jane and Alice Sanger emerged from the engineering level below the countryside, where their father worked in climate control. They usually visited him after school.

  “Hi, Max!” the twins called out together, and smiled the same broad smile as he went by them. Sometimes one of them would call out “Hi,” and the other “Max,” and they also liked to finish each other’s math problems.

  “Hello,” he called back nervously, hurrying on; he didn’t feel like talking to anyone just now.

  He turned up the path to his house and stopped, as if seeing it for the first time. His father had once told him that single-level structures of its kind were common in vacation spots on Earth. They were temporary dwellings, with minimal insulation and security, and were usually made of wood or ceramic materials. The habitat’s perfect weather and enclosed, gardenlike conditions were made to order for such houses. Camp houses, his mother had called them. Trembling, he imagined his house empty, the hollow deserted and dark. His home had always been intended to be temporary. His whole world was temporary, and would expire like a school term—but no one would ever come back. Everyone was looking forward to the end.

  2

  “What’s the matter?” Joe Sorby asked in a tone of mild concern.

  Max stared down at his dinner, knowing that his father would never understand.

  “Well, what is it?” Joe asked again.

  “Nothing,” Max replied, looking up.

  His father smiled at him as if they were about to share a secret, then shifted his stocky body in the chair.

  “You’ve seemed sad for some time,” his mother said gently. Max looked into her large brown eyes, so much like his own that he often felt he could read her thoughts.

  Joe scowled. “Oh, come on, talking won’t hurt.”

  How could his parents understand? They had grown up with millions of people around them. They were going back to places they knew. Even Rosalie, who had been born on Bernal One, the large habitat in the orbit of Earth’s Moon, was used to many thousands of people, and she had visited Earth and the Moon.

  Max had no idea if any of the other kids felt as he did behind their show of looking forward to coming home, of visiting all the places and things they had read about, seen in films, videos, and holos, or been told about by their parents. Some of them had to be faking, but he wasn’t close enough to any of them to know how they felt about most things. Even Muhammad Bekhter, still often mistaken for his best friend, was only someone he had studied and cycled with a few times. Max had never tried to be a real friend, and Muhammad had naturally started spending more time with others. Max couldn’t believe that some of them weren’t upset by the fact that their home would soon be taken away from them.

  Not that there was really any way for him to find out. If he admitted his own fears to someone else, he might only end up with the others mocking him, and with even more assurances from his parents and other adults that everything would be just fine.

  “Max,” his mother said in a firm but still kindly voice, “tell us what’s wrong. We’ll try to understand.”

  They meant well, but they wouldn’t understand. The ship-habitat had been built for a purpose that was now almost achieved, and soon it would be time to do something else. They would say he was being backward and selfish, unreasonably attached to something no one should have this much feeling about.

  “I know it shouldn’t bother me,” he said finally. “We’ve all been looking forward to the return.” He paused suddenly, his throat dry, and said bitterly, “But not me. You all came from there. . . .”

  Joe was looking at him intently. “I had no idea you felt this way.”

  “It’s not fair!” Max blurted out. “I never had any say in it.” He took a long sip of water, unable to go on.

  “I understand,” Rosalie said. “You grew up here, and now it’s going to be taken away.”

  Max nodded, feeling ashamed.

  Joe sighed. “I see you’ve thought about this, but it’s really nothing to get upset about. Back on Earth, kids who grew up in small towns were often afraid of moving to big cities.”

  Max took a deep breath. “Then why’d they have to?”

  “Lots of reasons. Their parents had to relocate for work, or the kids had to go to school in a big city. Sometimes they ran away to the big city because they hated their small towns.”

  “I’m sure you’ll like a bigger world,” Rosalie added, “when you see what it’s like.”

  Max swallowed and was silent. Great. They had it all backwards.

  “We’re just a small town, really,” his mother said. “Don’t you see that it would be wrong for you not to ever know anything else?”

  “I suppose so,” Max replied.

  His parents were silent.

  “We’ll never come back here again,” he added in a breaking voice.

  “Who knows?” Joe said, leaning forward and patting him on the shoulder. “Maybe they’ll use this place to go somewhere else. We’ve shown that it’s pretty safe to live in. They’ll refit it with better collision shielding, so it can get closer to light speed, and new people will move in and take it out again.”

  “You don’t really think so,” Max said, imagining strangers sitting at this table.

  Joe shrugged. “It’s possible.”

  “We’ll never see this house again,” Max added.

  His mother smiled. “You know we can’t decide any of these things. Did you think we’d live here forever?”

  “Look, son,” Joe said firmly, “we have no say in what will happen to this habitat after we return it, and there’s no reason why we should. The plan was to take it out and come back. We’ll make new lives. One thing will end and another begin. I think you understand that. It will happen to you several times in the long life you’ll live.”

  Max was silent, knowing they were right, but his feelings rebelled.

  “Hey,” Joe said suddenly, “we should be at the community center. The Sun’s close enough now to show up bright, and the broadcasts will probably start getting through our interference tonight.”

  “I don’t feel like it tonight,” Max answered.

  “Come on,” his father said. “Everyone else is probably over there by now.”

  “There’s so much that’s happened since we’ve been gone,” Rosalie said excitedly. “We’ll have to work hard to take it all in. I mean, we know generally what’s been going on, but it’s like learning history—we’ll know what happened, but never as if we’d lived it. We can’t get back the time we lost. I feel apprehensive about coming back, but for different reasons than yours, Max.”

  “Just think, son,” Joe said. “You’ll be going from this small world to a much larger one. A whole Sunspace of worlds.”

  “But it’s not right that we should lose our home, Dad.”

  “You’re looking at it all wrong,” Joe said impatiently, and Max knew his parents were thinking that he’d forget how he felt as soon as new things came along to distract him. “You can’t hang onto your first home forever.”

  “We’re late,” Rosalie said, getting up from the table.

  He would never forget, Max promised himself.

  3

  They got on their bikes and pedaled toward the sunplate, Max on his racer, Joe and Rosalie on their two-seater, with Joe in the back. The light dimmed toward what his parents called moonlight. He pushed on ahead, making his best speed, feeling guilty that he couldn’t share his parents’ eagerness. He glanced at his father and saw the look of a stranger who might become angry.

  The roads and walkways were empty. Almost everyone would already be at the center, anticipating that direct contact with Earth would come today. When the sunplate was only a few hundred meters away, it towered over the nearby landscape.

  Max pulled up to the Community Center’s bike rack. His parents caught up and parked their bike next to his. Together they walked into the ramp tunnel under the sunplate and came up into the amphitheater.

  “We’re the last ones in,” Joe said as they entered the two-hundred-meter-diameter spherical space cut in the forward section of the asteroid. The lower half of the sphere cradled two thousand seats, but more than five hundred were now empty because almost that many people had chosen to stay behind in the new habitat at Centauri. The great center space was already aglow as Max and his parents took seats at the end of the top row in the first section. The center space was for projecting plays, educational programs, operas, ballets, old films, videos and holos from Earth, as well as for display of information during Town Meetings. The much smaller chamber of the Control Bridge was just above the Community Center.

  The glow in the great space meant that the forward view was picking up the countless collisions with gas and dust in the deflecting shield’s field as the habitat slowed from two-thirds of light speed.