He lay down on the sand. His helmet cam now mostly showed the sand under him, rumpled and granular, flecked with streamers of foam. Broken waves swept up the strand, stalled, retreated in a pebbly rush, leaving a line of foam. The water hissed and grumbled, and occasionally waves offshore cracked dully. Tau Ceti had separated from the sea cliff now, and all the water between the beach and the horizon was a bouncing mass of blue and green. The broken waves were an intense tumbling white. The waves as they were about to break turned translucent. Euan sounded like he might be asleep. Freya herself nodded over her arms, put her forehead on the table.

Much later something caused her to raise her head. She watched as Euan stood up.

"I'm hot," he croaked. "Really hot. I guess it's got me."

He dug around in his little backpack.

"Well, I'm out of food anyway. Water too."

He tapped away at his wristpad. There was a whirring noise.

"There you go," he said. "Now I can drink from the stream. From the pool here too, I'm sure. It must be mostly fresh."

"Euan," Freya croaked. "Euan, please."

"Freya," he replied. "Please yourself. Look, I want you to turn your screen off."

"Euan-"

"Turn your screen off. Wait, I guess I can do it myself from here." He tapped again at his wristpad. Freya's screen went dark.

"Euan."

"It's all right," he said out of the dark screen. "I'm done for. But we're all done for sometime. At least I'm in a beautiful place. I like this beach. I'm going to go for a swim now."

"Euan."

"It's all right. Turn your sound off too. Turn it down anyway. These waves are loud. Wow, this water is cold. That's good, eh? Colder the better."

Water sounds enveloped his voice. He was saying "Ah, aah," as if getting into a bath that was too hot. Or too cold.

Freya held her hands over her mouth.

The watery sounds got louder and louder.

"Aah. Okay, big wave coming! I'm going to ride it! I'm going to stay under if I can! Freya! I love you!"

After that there were only water sounds.

Several of the people in Hvalsey disappeared into the surrounding countryside. Some went off in silence, suit GPSs disabled; others stayed in communication with their friends on the ship. A few broadcast their ends to anyone who cared to watch and listen. Jochi stayed in his car and refused to speak to anyone, even Aram, who grew silent himself.

Then all of the Hvalsey survivors except for Jochi ignored instructions from the ship to stay on Aurora and prepped one of the ferries to return them to orbit. Doing this without help from the ship's ferry technicians was difficult, but they looked up what they had to know in the computers they had, and fueled the little craft with liquid oxygen and crammed into the ferry, and used the spiral sling and rocket boost to achieve a rendezvous with the ship in its orbit.

As they had been forbidden reentry into the ship, and told that no quarantine was going to last long enough for them to be judged safe to reenter, it was an awkward question what to do when their ferry arrived to dock with the ship. Some in the ship said that if those in the ferry survived for a certain period of time, say a year (some said ten), then it would be obvious that they were not vectors for the pathogen, and could be allowed to reenter. Others disagreed with that. When the committee that was hastily convened by the executive council and charged with making the decision announced that they did not think there was any quarantine period long enough to prove the settlers were safe, many were relieved to hear it; others loudly disagreed. But the question still remained what to do about the landing party, now approaching the ship in its orbit.

The emergency committee spoke to the Greenlanders by radio, telling them to keep a physical distance from the ship, to remain near it as a kind of small satellite of it. The Greenlanders agreed to that, at first; but when they were running out of food, water, and air, and resupplies did not appear when promised from the ship, due to a technical problem with the ferry being used for the task, as was explained to them, they nevertheless powered their ferry in and approached the main lock in the ferry dock, at the stern end of the spine. From there they proposed to occupy Inner Ring A's rooms at Spoke One, with the rooms permanently sealed off from the spine and the biomes. They would remain in those rooms and become as self-sufficient as possible, for as long a quarantine period as the people on the ship required. After that the question of reintegration could be reconsidered, and if people on the ship had become comfortable with the idea, the settlers might be able to rejoin the larger life of the ship.

After a brief meeting, permission to pursue this plan was expressly denied by the committee, as representing too much of a danger of infection to all the life on the ship. A small crowd of people, mostly men from Patagonia and Labrador, the two biomes at the end of Spoke One, gathered outside the ferry dock's lock door and exhorted each other to resist any incursion by what they called the infected party. Others were alarmed when they saw on screens that this group was gathering, and some of them began to get on the trams and head for the spine to intervene in some poorly defined manner. In Labrador and the Prairie the tram stops began to fill with people, many angrily arguing with other groups they ran into. Fights broke out, and some young men levered the tram tracks off their piste in the Prairie, stopping traffic from moving around Ring B.

Hanging just outside the docking port, the settlers in their ferry reported that overcrowding in their little vehicle had caused something in it to malfunction in such a way that they were quickly running out of breathable air, and they were therefore going to enter the ship's dock as proposed. They warned those in the ship that they were coming in, and the people inside the dock's main lock door told them not to do it. People on both sides were shouting angrily now. Then lights on the operations console inside the dock showed that the settlers were coming in, and at that point some of the young men inside the operations room rushed the security council members there operating the lock, knocking them down and taking over the console. By now the shouting was such that no one could understand anyone else. The ferry entered the docking port, which automatically secured it in position. The outer door of the dock closed, the dock was aerated, and the dock's entry walktube extended to connect the ferry hatch to the inner lock door, all automatically. The settlers in the ferry opened their hatch and began to leave the ferry by way of the walktube, but at the same time, the people now in charge of the dock's operations console locked the inner lock door and opened the outer lock door, which in three seconds catastrophically flushed the dock and the walktube and the opened ferry of their air. All the seventy-two people in the ferry and walktube then died of decompression effects.

Surely the bad times had come again.

4.

REVERSION TO THE MEAN.

News of the disaster spread through both rings within minutes, and after an initial uproar there fell on most of the biomes a deathly quiet. People didn't know what to do. Some got on trams to Patagonia and then headed up Spoke One, talking loudly of charging those who had blown the dock with mass murder. Others got on trams, sometimes the same trams, intending to defend the people who they said had handled the incursion as best they could, saving everyone aboard from a fatal infection. Unsurprisingly, several fights broke out, and some trams braked to a halt, after which their occupants spilled onto the streets, fighting and calling around the rings for reinforcements.

"No!" Freya kept shouting through her tears, watching her screen as she hastily dressed to leave their apartment. "No! No! No!" She threw things at the walls as she banged around her bedroom, looking for her shoes.

"What are you going to do?" Badim asked her from the door.

"I don't know! I'm going to kill them!"

"Freya, don't. You need to have a plan. Everyone is upset, but look, the people who have died are dead, we can't get them back. It's happened. So now we have to think about what to do next."

Freya was still looking at her wristpad. "No!" she shouted again.

"Please, Freya. Let's think about what we can do now. You can't just wade in there and join the fight. That'll happen without you. We have to think what we can do to help."

"But what can we do?"

She found her second shoe and jammed her foot into it, then sat there.

"I'm not sure," Badim confessed. "It's a mess, no doubt about it. But listen-what about Jochi?"

"What about him? He's still down there!"

"I know. But he can't stay there forever. And while everyone is caught up in the disaster here, I'm wondering if we could take advantage of that, and get him up here."

"But they'll kill him too!"

"Yes, if he tries to enter the ship. But if he takes a ferry up here, and stays in the ferry, he would be within reach. We could resupply him, talk to him. There's a good chance he isn't infected with this pathogen. After a while that will become clear, and we can move on from there."

Freya had begun to nod. "Okay. Let's talk to Aram. He'll want to know about this and help."

"That's right."

Badim began tapping at his wristpad.

Aram was very happy to work on a plan to rescue Jochi, and he agreed with Badim that until the chaotic fighting among the people in the spine came to an end, there was very little they could do to help in the ship. Already the crowds there were massed into groups shouting at each other, with young men occasionally coming to blows. These were ineffective and dangerous in the spine's microgravity, but that didn't stop the fighting. Aram and Badim were in touch with many friends on the various councils, and most felt they should close the spine to people, as it was so full of the critical machinery of the ship. But with angry people floating up and down the spine passageways, shouting and getting in fights, it was not obvious how to secure the situation in the first place. Security council members were beginning to occupy the spokes to try to prevent anyone else from getting into the spine, but this was not a complete solution. It was a dangerous situation.

In those fraught hours Aram and Badim and Freya called Jochi, and after repeated entreaties, he replied.

Apparently he was aware of the docking disaster. He sounded unlike himself, voice grim and low. "What."

Aram explained their plan for him.

"They'll kill me too," he said.

Freya assured him that wouldn't happen. Many aboard were outraged at what had happened and would be intent on protecting him. If he stayed in his ferry, no one aboard would try to destroy it. Her voice shook as she said this.

Aram said, "Your ferry would be both quarantine and sanctuary. We could keep it in place magnetically, so there would be no physical connection to the ship. But we could send you supplies, and keep you going until the situation here changes."

"The situation will never change," Jochi said.

"Nevertheless," Aram said, "we can keep you alive, and see what happens."

"Please, Jochi," Freya added. "Just get in the ferry, and we'll help you to get it launched. There are so many people here who want something good to happen. Do it for us."

Long silence from the surface of Aurora.

"All right."

He drove the car he had taken refuge in across the burren to the settlement's launch facility. Looking at the empty pads and buildings on the screen in Badim and Freya's kitchen, Aram said, "They already look like they've been abandoned for a million years."

The launchers were still functional, however, and from the ship they helped Jochi to locate and fuel the smallest launch vehicle still on Aurora.

Fully suited, Jochi left his car and crossed to the ferry and climbed the steps into it, moving slowly and uncertainly through it to its bridge room. From the ship they tele-operated the push-cars and moved the ferry into the launch tube of the facility's spiral launcher. This was slow and difficult waldo work. Once in the tube, however, what followed was largely automatic; the rising spiral of the launch tube rotated on its base, which was also rotating, and the magnets in the tube pulled the ferry up the near vacuum in the tube, a pull augmented by the centrifugal force of the doubled spin of the tube and its base. By the time the ferry left the tube it was already moving at nearly escape velocity, its ablation plate heating rapidly, burning off five centimeters or more as the ferry's rockets fired and it shot up through the atmosphere to its rendezvous with the ship. For over a minute Jochi had to lie there enduring 4 g's; but his ferry was successfully launched.

Four hours later it was magnetically tethered to the ship, between Inner Ring A and the spine. By the time its magnetic docking was completed, news of Jochi's arrival had already spread throughout the ship. Many were happy to hear it; others were outraged. The news only added to the turmoil in the spine, which had not died down and indeed continued unabated.

The only survivor of the Aurora landing party had nothing to say.

So there they were: in the ship, in orbit around Aurora, which was in orbit around Planet E, which orbited Tau Ceti, 11.88 light-years away from Sol and Earth. Now there were 1,997 people on board, ranging in age from one month to eighty-two years. One hundred twenty-seven people had perished, either on Aurora or in the ferry in the ship's stern dock. Seventy-seven had died in the dock decompression.

Because the plan had been to relocate most of the human and animal population of the ship down to Aurora, they were now somewhat low in supplies of certain volatiles, rare earths, and metals, and to a certain extent, food. At the same time the ship was overfull of certain other substances, mainly salts and corroded metal surfaces. Various unequal inputs and outputs in the ecological cycles in the ship, the imbalances that Devi had called metabolic rifts, were now causing dysfunctions. At the same time, evolution of the many species on board continued to occur at different rates, with the fastest speciations occurring at the viral and bacterial level, but at slower speeds in every phylum and order. Ineluctably, the occupants of the ship were growing apart. Of course every life-form in the little ecosystem was in a process of coevolution with all the rest, so they could only grow apart so far. As a supraorganism they would perforce remain a totality, but one that could become markedly less hospitable to certain of its elements, including its human component.

In other words, their only home was breaking down. They were not fully aware of this fact, possibly because they themselves were growing sick, as one aspect of their home's breakdown. It was an interrelated process of disaggregation, which one night Aram named codevolution.

This was social as well as ecological. The confrontation in the spine continued, its floating crowds still angrily denouncing or defending what had occurred in the dock. In the midst of the arguments, a group of people barged into the dock's operation room and tele-operated robots in the open chamber of the dock, moving all the bodies that were still floating free in the chamber back into the doomed ferry. When that grim task was accomplished, the ferry's door was closed and the ferry ejected from the dock into space.

"We're just making sure," this group's spokespersons announced. "This dock is now closed for good. We're sealing it off. We'll leave the outer door open, and presumably the vacuum will sterilize it, but we aren't taking any chances with that. We're sealing the inside doors. No more access. We'll have to use the other docks now. No sense having such a disaster happen without making sure it keeps us safe."

Ejecting the bodies of seventy-seven of their fellow citizens in a pilotless ferry was denounced as a callous act, a desecration of people whose surviving family and friends were all in the ship. The dead had been integral members of the community until all this happened; now their bodies wouldn't even be returned to the cycles to nourish the generations to come. In the fights still breaking out over control of the spine, these grievances were shouted out, and just as loudly denied.

Freya went up to the spine to see if she could do anything to defuse the situation. She floated up and down the passageways, pulling herself on the cleats and stopping abruptly to talk to people she knew. People saw her and shot through the air at her to tell her their views and see what she thought. Soon she moved in the center of a group that moved with her down the spine.

No one attacked her, although it often looked like it was about to happen. When people yanked to a halt before her, she asked people what they thought, as in the years of her wandering. If they asked her what she thought, she would say, "We've got to get past this! We've got to come together somehow, find a way forward-we don't have any choice! We're stuck with each other! How could you forget that? We've got to pull together!"

Then she would urge everyone to get out of the spine and back down into the biomes. It was dangerous up there, she pointed out. People were getting hurt, the ship could get hurt. "We shouldn't be up here! The ferry is gone, those people are gone, there's nothing more that can be done here. Nothing! So get out of here!"

Hours passed while she said things like this to people. Some of them nodded and descended the spokes to the rings. Down there the struggle over access to the spokes went on. There were not enough people committed to guarding all twelve spokes, and some were still being used to get up to the spine. Fights occurred in the spokes, and here, if people fell or were shoved off the stairs running up the inner walls of the spokes, they could fall to their deaths. In Spoke Five three young men died tangled in a single fall, and after that the shock of the blood on the floor seemed instrumental in getting that spoke closed to all traffic.

Meanwhile, up in the spine, the permanent closing of the fatal dock continued. The group in charge there applied a thick layer of sealants to its inner lock doors, then covered those with a layer of diamond spray sheathing. It was excessive, some kind of ritual action-an erasure of the scene of the crime, or an excision of infected flesh.

Back in the Fetch, Badim and Aram watched the screens anxiously, switching around to a number of different cameras to see it.

"They've gone crazy at the dock," Aram said at one point as they left for a meeting. "It's a mess. I don't see what we can do."

A meeting of the councils had been called in Yangtze to discuss the situation. Some felt they needed to discuss what to do now that Aurora was revealed to be poisonous to them. Discord would continue until they had a plan, these people said. Aram and Badim weren't so sure, but they went and listened.

When the meeting in Yangtze began, the people in charge of the sealed dock floated back to the A spokes, and at Freya's urging, they and everyone else in the spine descended to the biomes. Most of them went down Spoke Three and headed directly to the meeting in Yangtze, so it seemed that calling the meeting had indeed helped to clear the spine. Even if it did nothing else, Badim remarked, it had been good for that.

In Yangtze there was a big crowd gathering in the central plaza. The main speaker at first was Speller, who had become one of the leading figures in the engineering group after Devi's death. And in fact he began by insisting that the ship's biomes were fundamentally healthy. "The ship's biosphere is a self-correcting entity," he said. "It can endure for centuries, if we just let it self-correct. Our interference has been impeding its ongoing homeostatic process. We only have to resupply it with the volatiles we're short on, and we'll be good to continue to a more hospitable planetary system."

At the back of the room Aram shifted toward Badim and said, "Do you think he means it?"

"Yes," Badim said.

Certainly it seemed so. "The ship got us this far," Speller went on. "It's a life-support system of proven robustness. It will last for centuries more, if we take care of it, which means mostly staying out of its way. All we have to do is restock the elements we're running low on. All those elements are common in the Tau Ceti system. So there is no cause for despair. We can still find a new home."

The nearby star RR Prime held great promise, Speller told them. It was just seven light-years away from Tau Ceti, an M-class star with a full array of planets, including three in its habitable zone, which, as usual around M stars, was closer to its star than Earth was to Sol. The planetary system there had been discovered in the 2500s, and though they were in possession of all the information the Terrans had had about it twelve years before, the fact was that not much was known about it. But it was quite possible this system could provide them with a home. "What else can we do?" Speller asked. "It's clearly our best chance. And the ship can get us there."

But many others were now arguing for Tau Ceti's Planet F's second moon. It was a nearly Earth-sized moon, like Aurora, but denser. It was tidally locked to F, and rotated around F in almost exactly twenty days, so it was not much different from Aurora and E in that regard. It was a rocky moon, and completely dry except for a little comet-impact water ice. Up until now it had been presumed to be lifeless, being almost free of water. But the experience on Aurora had made them more uncertain in judging this matter. Some people pointed out that meteorites had to have been ejected from Aurora by asteroid impacts, and some of them cast up the gravity well to land on F's Moon 2. That such rocks could have successfully transferred the Auroran life-forms, given the lack of water and air on F's moon, seemed unlikely, but it could not be entirely ruled out. Life was tenacious, and the pathogen on Aurora was still not understood. Even naming it was a problem, as some called it the cryptoendolith, others the fast prion, others the pathogen, and others simply the bugs, or the thing, or the stuff, or the alien, or the whatever.

Be that as it may, F's Moon 2 remained a real possibility in the minds of many of them. "Water can be imported to it," Heloise said in all the meetings. She was a leader in Ring A's ecology group. "F's Moon One is an icy moon, we can move that water over. We can build underground stations to start with, then expand those while the process of terraforming gets started. Then domed craters, then tent cities. It can work. It was part of the plan all along, after all. The backup if Aurora didn't work out. And then there wouldn't be the need for another interstellar trip, which is good, because it isn't certain the ship will sustain that. This was always the secondary option, and now we need it. And it can work."

Aram didn't believe this, and stood up to say so. "It would be like living in the ship," he said. "Except we would be buried in the lithosphere of a rocky moon. After that it would take many hundreds of years, or more likely thousands of years, to terraform this moon, and during that whole time we would be confined to interiors like these biomes. The problems plaguing us here would plague us there. We wouldn't live long enough to reach the time when we could move out into open air. Our descendants would get sick and die. They would go extinct."

This pessimism, or dark realism, whichever it might be, enraged Speller and Heloise, and everyone trying to make the best of things, trying to find a way forward. Why be so negative? they asked.

"It's not me being negative," Aram would reply. "It's the universe obeying its laws. Science isn't magic! We aren't fantasy creatures! We have been dealt a hand."

"So what do we do?" Heloise said angrily. "What are we supposed to do, in your opinion?"

Aram shrugged at this.

Freya called in to the meeting that was discussing the situation, from the spine where she was just now coming down, in the last group of peacemakers.

She said, "We should go home."

Silence greeted this pronouncement. Air vents, electrical hums.

"What do you mean?" Speller asked.