"She's got quite a fever," Badim said quietly, as if to Freya. "Pulse fast and shallow, a little a-fib, T cell counts high in the bloodstream. Cerebellum working hard. Looks like she's fighting something off."

"But what?" Freya said, as if for Euan.

"I don't know. Maybe something a little toxic, there in the mud. Some accumulation of some metal or chemical. We'll have to analyze for that."

"Or maybe there's some bug going around in Hvalsey that she caught," Freya said. There were, of course, many viruses and bacteria in the ship, and therefore in Hvalsey too.

"Yes, maybe so."

"Or maybe she's gone into shock," Euan said from off his screen.

"It's slow for a shock reaction to that cut," Badim said. "But you're right, we should look at that. You should look at all that, but keeping her in iso. Do it by extensions. And really, the rest of you who came in contact with her should get into iso as well. Just to be safe."

Again no reply from Euan.

Well, it was rubbish news, no doubt of that. Anyone would be disturbed. But for Euan, taking such obvious delight in his excursions on the surface, arguing vehemently for the opening of their helmets and the breathing of the open air of Aurora, it hit particularly hard. One could feel it in his silence.

When their call ended, Badim stood and shuddered, then just stood there for a long time, his head down.

"Better call Aram," he said at last. "And Jochi. He should probably be in iso too. The problem is, they all should be isolated from all the rest, and they can't do that."

As it turned out, Jochi had been out in one of the expedition cars when the news of Clarisse's fever came, and when he heard the news, he stayed in the car, locked inside. He acknowledged to the others in Hvalsey he was there, but refused to discuss his situation any further. There was air, water, food, and battery power to keep him out there for three weeks. People in Hvalsey spoke angrily to him, but he didn't reply. The people up in the ship didn't know what to say. Badim just shook his head when Freya asked him what he thought.

"He might be right," Badim said. "I wish there was a car for everyone. But there isn't. And no one person can stay isolated for long, there or anywhere."

It was the middle of the night on 170.153, A0.113, and Freya was sleeping restlessly, when her screen spoke to her, quietly at first, so that Freya first muttered things, in what sounded like a dream conversation with her mother; but as the voice from the screen repeated "Freya... Freya... Freya," in a way that Devi never would have, she finally woke, groggily.

It was Euan, in Hvalsey. "Euan?" Freya said. "What is it?"

"Clarisse died," he said.

He didn't have his camera on, or was sitting in the dark; it was just his voice, the screen was dark.

"Oh no!"

"Yes. Last night."

"What happened?"

"We don't know. Looks like she had some kind of anaphylactic shock. As if she ran into something she was allergic to."

"But what is there to be allergic to?"

"I don't know. Nothing. She had asthma, but that was controlled. They gave her epinephrine four times, but her blood pressure dropped, her throat seems to have closed up on her, the ventral part of her heart went arrhythmic. The scans are showing empty heart..."

Long pause.

"She was still in isolation?"

"Yes. But of course she wasn't when we brought her back in."

"But you were all in your suits."

"I know. But we took them off inside. We all helped her."

He didn't say more, and Freya didn't speak either. They were in trouble down there, if what had happened to Clarisse had been caused by her accident. They wouldn't be able to go out on the surface until they understood what it was. And if they determined that some local life-form had infected and killed her, they wouldn't be able to go out ever again without massive precautions.

Nor would they be able to associate with each other freely, until it was demonstrated that whatever had killed her wasn't contagious.

Nor could they come back up to the ship and risk infecting it.

So now they were confined to a biome much smaller than any on the ship, and maybe an infected one at that. Maybe a poisoned building, in which everything alive in it was already doomed.

All these possibilities were no doubt occurring to Freya, as they must have already to Euan. Thus the long silence.

Finally she said, "Is there anything I can do?"

"No. Just... be there."

"I'm here. I'm sorry."

"Me too. It was... It was beautiful down here. We were... I was having fun."

"I know."

She woke Badim and told him, then lay down on the couch in their living room, while Badim sat at their kitchen table making calls.

In between his calls she said to him, "I miss Devi. If she were alive, none of this would have happened. She would have insisted that we test the surface of the planet completely before anyone landed."

"Hard to do by robot," Badim remarked absently.

"I know. Years would have passed, everyone would have been furious with her. She would have been furious with them. But this wouldn't have happened."

Badim shrugged.

Later Euan called them again.

"I'm going out again," he said.

"What!" Freya cried. "Euan, no!"

"Yes. Look. We all have to go sometime. So, maybe we've been fatally poisoned, maybe not. We'll know soon enough. In the meantime, as long as your suit integrity is good, there isn't any difference between staying in the compound or going outside. So I'm going to damn the torpedoes and go. I don't see why not. Either way it'll be okay. I mean, either I'm already infected, and I might as well spend my last days having fun, or I'm not, and I won't be, as long as I don't cut my suit open. Silly woman, I wish she hadn't gone off the path, that was obviously quicksand she went off into, I don't know what she could have been thinking, what she was going after. A blink on the water, she said. But really? Well, we'll never know now. And it doesn't matter. I'll stay on hard ground. Maybe I'll stay out of the estuary and up on the sea cliffs, that's the best views anyway. Go out and see the dawn. No one here will stop me. We're all sequestered anyway. Everyone's locked in a room somewhere. No one could stop me without endangering themselves, right? And no one wants to anyway. So I'm going out to see the dawn. I'll call you back in a little while."

Life in the ship went silent, and took on the nature of a vigil, or a death watch, or even a wake. People murmured about the situation down on the surface, in theory speaking hopefully, in fact frightened and assuming the worst. Of course the woman could have died from shock, or asthmatic attack, or from an opportunistic growth of bacteria she already carried in her, part of the bacterial stock from the ship itself, which was by no means entirely benign, as they had often learned. As Aurora was or seemed to be inert, this last was even the likeliest explanation.

But was Aurora inert? Was it a dead moon, as it seemed to be? Was the oxygen in the atmosphere a result of abiologic processes, as had been assumed by the chemical signatures, and the lack of evident life on the moon? Or was there some kind of life they weren't seeing, perhaps there in the mud of Half Moon Valley's estuary?

But if it was in one place, it would be in more. So the ship's biologists shook their heads, in frustration and ignorance. Euan went back out into the field, and since he was willing to do it, there were people who wanted him to bring back samples of mud from the region where Clarisse had fallen, to get as close to that quicksand as he dared, dig down and secure some mud in a safe flask, then bring it back to Hvalsey for study under the hoods. They already had the mud from Clarisse's suit, of course, and they had her body, so the extra samples weren't absolutely necessary, but some of the microbiologists wanted them anyway, to be able to check the local matrix uncontaminated by all that had happened since Clarisse had fallen into it.

Euan was happy to do this. Some of the other people in Hvalsey were also, and they went out in little groups, staying on trails and descending to the estuary in short expeditions, very unlike their previous trips. They hiked in silence, as if walking across a minefield, or making descents into hell. Raids on the inexpressible. Euan alone among them sang little ditties to himself, including a tune with the refrain "Shadrach, Meshach, and Abednego"-an old spiritual or faux spiritual, ship determined, with a biblical reference to prisoners of Babylon, surviving time in a fiery furnace by way of a protective intervention from Jehovah.

Euan sang these songs off the public channels, speaking only to Freya on their private channel. Some of the other explorers were behaving similarly, speaking only to people they knew well. On the ship, word of their various expeditions then spread by word of mouth. Those on the surface seemed to feel a new distance from those on the ship. It was all different than it had been before.

Jochi stayed in his car, sealed away from all the rest of the settlers, eating dried and frozen food. One night he suited up and went to one of the other expedition cars and took all the food and portable air tanks in it back to his car.

He had requested permission to return to the ship; every day's communication from him to the ship began with the same request. So far the ship's governing council had only refused his request once, and after that, left their refusal unspoken. No one was to be returned for now. The settlers were under quarantine.

So Jochi spent his time in his car, looking at his screen. He was able to operate some of the robotic medical devices under the hoods in the clinic lab where Clarisse had died, and he spent some of his time investigating the mud Euan and the rest had brought back in, making use of the clinic's electron microscope. His training with Aram and the math team had been in mathematics, but as part of that team he had sometimes worked with the biophysicists, and in any case he was now investigating as much as he could, so Aram expressed the hope that he might find something helpful. Aram was sick with worry that Jochi was down there; he spent many hours in Badim and Freya's kitchen, hunched over and wan, looking at the screens like everyone else.

For a long time Jochi said nothing about what he was finding. When Freya asked him about it, he only shrugged and looked out at her from her screen.

Once he said, "Nothing."

Another time he said, "Mathematics is not biology. At least not usually. So, I don't know what I'm doing."

"Should I send you more of the medical archives from the solar system feed?" Freya asked.

"I've looked at the index. I don't see anything that will help."

A week later, more than half the people in Hvalsey had fevers. Jochi stayed in his car. He didn't ask to return to the ship anymore.

Euan started going out into the estuary again, or the sea cliffs. He slept out there, and seldom came in to eat. Everyone in Hvalsey behaved a little differently, and it wasn't clear they were talking to each other very much. One day a few of them arranged a dance, and they all wore something red to it.

Jochi called Aram one morning and said flatly, "I think I may have found the pathogen. It's small. It looks a little like a prion, maybe. Like a strangely folded protein, maybe, but only in its shape. It's much smaller than our proteins. And it reproduces faster than prions. In some ways it's like the viris that live inside viruses, or the v's, but smaller. Some seem to be nested in each other. The smallest is ten nanometers long, the largest fifty nanometers. I'm sending up the electron microscope images. Hard to say if they're alive. Maybe some interim step toward life, with some of the functions of life, but not all. Anyway, in a good matrix they appear to reproduce. Which I guess means they're a life-form. And we appear to be a good matrix."

"Why us?" Aram asked. He had linked Badim into the call, given its significance. "We're alien to the place, after all."

"We're made of organic molecules. Maybe it's just that. Or we're warm. Just a good growth medium, that's all. And our blood circulation moves it around in us."

"So they're in that clay from the estuary?"

"Yes. That's the highest concentration. But now that I've found them, I've seen a few almost everywhere. In the river water. In seawater. In the wind."

"They must need more than water."

"Yes. Sure. Maybe salts, maybe organics. But we're salty, and organic. And so is the water down here. And the wind rips the salts right into the air."

When three more of the people in Hvalsey died in the same way as Clarisse, of something like anaphylactic shock, and then Euan came down with a fever too, he went out by himself, around the estuary's edge to the beach under the short cliffs, at the south end of the lagoon.

It was windy as always, the offshore wind of the midmorning of the daymonth. So once he got onto the beach and under the sea cliffs, he was mostly out of the wind. The katabatic gusts came barreling down the gap of the estuary and hit the incoming waves, holding up their faces for a time as they rose up in the shallows, also flinging long plumes of spray back from the crests. These arcs of spray were barred by fat little rainbows, called ehukai in the Hawaiian language. Planet E was a thick crescent in its usual spot in the sky, very bright in the dark blue, so that the light in the salt-hazed air over the sea seemed to come from all directions, and suffuse everything. The double shadows there on the ground were faint, and every rock and wave seemed stuffed with itself.

"This would have been a nice place to live," Euan said.

He was talking only to Freya now, on their private channel. She was sitting on the chair by her bed, hunched over her stomach, looking at the screen. Euan was looking here and there, and her screen showed whatever he was looking at.

"A beautiful world, for sure. Too bad about the bugs. But I guess we should have known. That stuff about the oxygen in the atmosphere being abiologic-I guess you'll have to rethink that one. I suppose it could still be true. But if these things Jochi found exhale oxygen, then probably not."

Long silence. Then Freya heard him heave a breath, in and out.

"Probably they're like archaea. Or a kind of pre-archaea. You'll have to keep an eye out for that. There might be other chemical signals in oxygen that would reveal its origins. The ratio of isotopes might be different depending on how it got expressed into the air. I wouldn't be surprised. I know they thought they had a rubric there, but they'll have to recalibrate. Life might be more various than they thought. That keeps happening.

"Not that you'll have much of a chance to test it here," he went on after a while. He was walking on the beach now. The wind was scraping across his exterior mike, and rolling sand grains down the tilted beach into the foam surging up at his feet.

"I guess you'll have to try to do something with F's moon now. Presumably it's dead. Or even try E." He looked up at it, big in the blue sky. "Well, no. It's too big. Too heavy."

Two minutes later: "Maybe you can just keep living on the ship, and stock up on whatever you run out of, from here and from E. Terraform F's moon if you can. Or maybe you can resupply and get to another system entirely. I seem to recall there's a G star just a few more light-years out."

Long silence.

Then: "But you know, I bet they're all like this one. I mean, they're either going to be alive or dead, right? If they've got water and orbit in the habitable zone, they'll be alive. Alive and poisonous. I don't know. Maybe they could be alive and we live with them and the two systems pass each other by. But that doesn't sound like life, does it? Living things eat. They have immune systems. So that's going to be a problem, most of the time anyway. Invasive biology. Then on the dead worlds, those'll be dry, and too cold, or too hot. So they'll be useless unless they have water, and if they have water they'll probably be alive. I know some probes have suggested otherwise, like here. But probes never stop and test thoroughly. They might just as well be running their tests from Earth, if you think about it. Bugs like these we've got here, you aren't going to find those unless you slow down and hunt really hard. Live nearby for a while and look. At which point it's too late, if you get a bad result. You're out of luck then."

Long silence as he walked south along the beach.

Then: "It's too bad. It really is a very pretty world."

Later: "What's funny is anyone thinking it would work in the first place. I mean it's obvious any new place is going to be either alive or dead. If it's alive it's going to be poisonous, if it's dead you're going to have to work it up from scratch. I suppose that could work, but it might take about as long as it took Earth. Even if you've got the right bugs, even if you put machines to work, it would take thousands of years. So what's the point? Why do it at all? Why not be content with what you've got? Who were they, that they were so discontent? Who the fuck were they?"

This sounded much like Devi, and Freya put her head in her hands.

Later: "Although it is a very pretty world. It would have been nice."

Later: "Maybe that's why we've never heard a peep from anywhere. It's not just that the universe is too big. Which it is. That's the main reason. But then also, life is a planetary thing. It begins on a planet and is part of that planet. It's something that water planets do, maybe. But it develops to live where it is. So it can only live there, because it evolved to live there. That's its home. So, you know, Fermi's paradox has its answer, which is this: by the time life gets smart enough to leave its planet, it's too smart to want to go. Because it knows it won't work. So it stays home. It enjoys its home. As why wouldn't you? It doesn't even bother to try to contact anyone else. Why would you? You'll never hear back. So that's my answer to the paradox. You can call it Euan's Answer."

Later: "So, of course, every once in a while some particularly stupid form of life will try to break out and move away from its home star. I'm sure it happens. I mean, here we are. We did it ourselves. But it doesn't work, and the life left living learns the lesson, and stops trying such a stupid thing."

Later: "Maybe some of them even make it back home. Hey-if I were you, Freya? I would try to get back home."

Later: "Maybe."

Later, still walking south, Euan passed a ravine cleaving the sea cliff. The cliff was a little lower to each side of this cleft, and the cleft ran back and up into the burren at a steep angle, such that there was a clattering creek running down it, which pooled in the sand of the beach, under the cliffs to each side. Where the pool was closest to the sea, a shallow broad flow of water cut through wet sand and poured down to the swirling foam.

The wind whistled down the cleft. Higher up the cleft narrowed, and the walls to each side steepened, looked impassable. Rather than climb up there and investigate, Euan walked right through the beach stream, splashing fearlessly, though at its middle it was knee deep. His fever was quite high at this point. The numbers from his suit were there at the bottom of his screen, glowing red.

Freya hunched over, arms across her stomach, in a position she had often taken when Devi had been ill. She got up and went to their kitchen and got some crackers to eat. She chomped on the crackers, drank a glass of water. She inspected the water in her glass, swallowed some more of it, returned to her chair and the screen.

Euan continued south and came to a broader part of the beach, with some wind-sculpted dunes sheltered under the cliff. He scrambled to the top of the tallest dune. Tau Ceti was a blaze too bright to look at, pouring its light over the top of the cliff and onto the ocean. Euan sat down.

"Nice," he said.

The wind was still at his back. As one looked down at the waves, it was clear that the wind held them up for a time as they tried to break; they swept in toward the land, then reared up and hung there with a vertical face as they moved onshore, trying to fall but getting held up by the wind; then finally the steepest section would pitch down in a roiling burst of white spray, some of which whiteness launched upward and was caught on the wind and hurled back over the wall of white water. Quick fat ehukai crossed these tails of spray.

"I'm feeling hot," Euan said. He walked off the edge of the dune and glissaded down the sand facing the sea.

Freya clutched her stomach under both forearms, put her mouth down on the back of one fist.

Euan looked out at the waves for a long time. The dark gray strand between beach pool and ocean was crosshatched with black sand streaks, far to each side of the shallow runnel of water pouring down into the breakers.

Freya watched him silently. His fever was really very high.