1

Marlene had last seen the Solar System when she was a little over one year old. She didn't remember it, of course.

She had read a great deal about it, but none of the reading had ever made her feel that it could ever have been part of her, nor she a part of it.

In all her fifteen years of life, she remembered only Rotor. She had always thought of it as a large world. It was eight kilometers across, after all. Every once in a while since she was ten - once a month when she could manage it - she had walked around it for the exercise, and sometimes had taken the low-gravity paths so she could skim a little. That was always fun. Skim or walk, Rotor went on and on, with its buildings, its parks, its farms, and mostly its people.

It took her a whole day to do it, but her mother didn't mind. She said Rotor was perfectly safe. 'Not like Earth,' she would say, but she wouldn't say why Earth was not safe. 'Never mind,' she would say.

It was the people Marlene liked least. The new census, they said, would show sixty thousand of them on Rotor. Too many. Far too many. Every one of them showing a false face. Marlene hated seeing those false faces and knowing there was something different inside. Nor could she say anything about it. She had tried sometimes when she had been younger, but her mother had grown angry and told her she must never say things like that.

As she got older, she could see the falseness more clearly, but it bothered her less. She had learned to take it for granted and spend as much time as possible with herself and her own thoughts.

Lately, her thoughts were often on Erythro, the planet they had been orbiting almost all her life. She didn't know why these thoughts were coming to her, but she would skim to the observation deck at odd hours and just stare at the planet hungrily, wanting to be there - right there on Erythro.

Her mother would ask her, impatiently, why she should want to be on an empty barren planet, but she never had an answer for that. She didn't know. 'I just want to,' she would say.

She was watching it now, alone on the observation deck. Rotorians hardly ever came here. They had seen it all, Marlene guessed, and for some reason they didn't have her interest in Erythro.

There it was; partly in light, partly dark. She had a dim memory of being held to watch it swim into view, seeing it every once in a while, always larger, as Rotor slowly approached all those years ago.

Was it a real memory? After all, she had been getting on toward four then, so it might be.

But now that memory - real or not - was overlaid by other thoughts, by an increasing realization of just how large a planet was. Erythro was over twelve thousand kilometers across, not eight kilometers. She couldn't grasp that size. It didn't look that large on the screen and she couldn't imagine standing on it and seeing for hundreds - or even thousands - of kilometers. But she knew she wanted to. Very much.

Aurinel wasn't interested in Erythro, which was disappointing. He said he had other things to think of, like getting ready for college. He was seventeen and a half. Marlene was only just past fifteen. That didn't make much difference, she thought rebelliously, since girls developed more quickly.

At least they should. She looked down at herself and thought, with her usual dismay and disappointment, that somehow she still looked like a kid, short and stubby.

She looked at Erythro again, large and beautiful and softly red where it was lit. It was large enough to be a planet but actually, she knew, it was a satellite. It circled Megas, and it was Megas (much larger still) that was really the planet, even though everyone called Erythro by that name. The two of them together, Megas and Erythro, and Rotor, too, circled the star Nemesis.

'Marlene!'

Marlene heard the voice behind her and knew that it was Aurinel. She had grown increasingly tongue-tied with him of late, and the reason for it embarrassed her. She loved the way he pronounced her name. He pronounced it correctly. Three syllables - Mar-LAY-nuh - with a little trill to the 'r'. It warmed her just to hear it.

She turned and mumbled, 'Hi, Aurinel,' and tried not to turn red.

He grinned at her. 'You're staring at Erythro, aren't you?'

She didn't answer that. Of course that's what she would be doing. Everyone knew how she felt about Erythro. 'How come you're here?' (Tell me you were looking for me, she thought.)

Aurinel said, 'Your mother sent me.'

(Oh well.) 'Why?'

'She said you were in a bad mood and every time you felt sorry for yourself, you came up here, and I was to come and get you because she said it would just make you grumpier to stay here. So why are you in a bad mood?'

'I'm not. And if I am, I have reasons.'

'What reasons? Come on, now. You're not a little kid any more. You've got to be able to express yourself.'

Marlene lifted her eyebrows. 'I am quite articulate, thank you. My reasons are that I would like to travel.'

Aurinel laughed. 'You've traveled, Marlene. You've traveled more than two light-years. No-one in the whole history of the Solar System has ever traveled even a small fraction of a light-year - except us. So you have no right to complain. You're Marlene Insigna Fisher, Galactic Traveler.'

Marlene suppressed a giggle. Insigna was her mother's maiden name and whenever Aurinel said her three names in full, he would salute and make a face, and he hadn't done that in a long time. She guessed it was because he was getting close to being a grown-up and he had to practice being dignified.

She said, 'I can't remember that trip at all. You know I can't, and not being able to remember it means it doesn't matter. We're just here, over two light-years from the Solar System, and we're never going back.'

'How do you know?'

'Come on, Aurinel. Do you ever hear anyone talk about going back?'

'Well, even if we don't, who cares? Earth is a crowded world and the whole Solar System was getting crowded and used up. We're better off out here - masters of all we survey.'

'No, we're not. We survey Erythro, but we don't go down there to be its masters.'

'Sure we do. We have a fine working Dome on Erythro. You know that.'

'Not for us. Just for some scientists. I'm talking about us. They don't let us go down there.'

'In time,' said Aurinel cheerfully.

'Sure, when I'm an old woman. Or dead.'

'Things aren't that bad. Anyway, come on out of here and into the world and make your mother happy. I can't stay here. I have things to do. Dolorette-'

Marlene felt a buzzing in her ears and she didn't hear exactly what Aurinel said after that. It was enough to hear - Dolorette!

Marlene hated Dolorette, who was tall and - vacuous.

But what was the use? Aurinel had been hanging around her, and Marlene knew, just by looking at him, exactly how he felt about Dolorette. And now he had been sent to find her and he was just wasting his time. She could tell that was how he felt and she could also tell how anxious he was to get back to that - to that Dolorette. (Why could she always tell? It was so hateful sometimes.)

Quite suddenly, Marlene wanted to hurt him, to find words to give him pain. True words, though. She wouldn't lie to him. She said, 'We're never going back to the Solar System. I know why not.'

'Oh, why's that?' When Marlene, hesitating, said nothing, he added, 'Mysteries?'

Marlene was caught. She was not supposed to say this. She mumbled, 'I don't want to say. I'm not supposed to know.' But she did want to say. At the moment she wanted everyone to feel bad.

'But you'll tell me. We're friends, aren't we?'

'Are we?' Marlene asked. She said, 'OK, I'll tell you. We're not ever going back because Earth is going to be destroyed.'

Aurinel didn't react as she had expected. He burst into a loud squawk of a laugh. It took him a while to settle down, and she glared at him indignantly.

'Marlene,' he said, 'where did you hear that? You've been viewing thrillers.'

'I have not!'

'But what makes you say anything like that?'

'Because I know. I can tell. From what people say, but don't say, and what they do, when they don't know they're doing it. And from things the computer tells me when I ask the right questions.'

'Like what things it tells you?'

'I'm not going to tell you.'

'Isn't it possible? Just barely possible' - and he held up two fingers very closely together - 'that you're imagining things?'

'No, it isn't possible. Earth won't be destroyed right away - maybe not for thousands of years - but it's going to be destroyed.' She nodded solemnly, her face intense. 'And nothing can stop it.'

Marlene turned and walked away, angry at Aurinel for doubting her. No, not doubting her. It was more than that. He thought she was out of her mind. And there it was. She had said too much and had gained nothing by it. Everything was wrong.

Aurinel was staring after her. The laughter had ceased on his boyishly handsome face and a certain uneasiness was creasing the skin between his eyebrows.

2

Eugenia Insigna had grown middle-aged during the trip to Nemesis, and in the course of the long stay after arrival. Over the years she had periodically warned herself: This is for life; and for our children's lives into the unseen future.

The thought always weighed her down.

Why? She had known this as the inevitable consequence of what they had done from the moment Rotor had left the Solar System. Everyone on Rotor - volunteers all - had known it. Those who had not had the heart for eternal separation had left Rotor before takeoff, and among those who had left was-

Eugenia did not finish that thought. It often came, and she tried never to finish it.

Now they were here on Rotor, but was Rotor 'home'? It was home for Marlene; she had never known anything else. But for herself, for Eugenia? Home was Earth and Moon and Sun and Mars and all the worlds that had accompanied humanity through its history and prehistory. They had accompanied life as long as there had been life. The thought that 'home' was not here on Rotor clung to her even now.

But, then, she had spent the first twenty-eight years of her life in the Solar System and she had done graduate work on Earth itself in her twenty-first to twenty-third years.

Odd how the thought of Earth periodically came to her and lingered. She hadn't liked Earth. She hadn't liked its crowds, its poor organization, its combination of anarchy in the important things and governmental force in the little things. She hadn't liked its assaults of bad weather, its scars over the land, its wasteful ocean. She had returned to Rotor with an overwhelming gratitude, and with a new husband to whom she had tried to sell her dear little turning world - to make its orderly comfort as pleasant to him as it was to her, who had been born into it.

But he had only been conscious of its smallness. 'You run out of it in six months,' he had said.

She herself hadn't held his interest for much longer than that. Oh well-

It would work itself out. Not for her. Eugenia Insigna was lost for ever between worlds. But for the children. Eugenia had been born to Rotor and could live without Earth. Marlene had been born - or almost born - to Rotor alone and could live without the Solar System, except for the vague feeling that she had originated there. Her children would not know even that, and would not care. To them, Earth and the Solar System would be a matter of myth, and Erythro would have become a rapidly developing world.

She hoped so. Marlene had this odd fixation on Erythro already, though it had only developed in the last few months and might leave just as quickly as it had come.

Altogether, it would be the height of ingratitude to complain. No-one could possibly have imagined a habitable world in orbit about Nemesis. The conditions that created habitability were remarkable. Estimate those probabilities and throw in the nearness of Nemesis to the Solar System and you would have to deny that it could possibly have happened.

She turned to the day's reports, which the computer was waiting, with the infinite patience of its tribe, to give her.

Yet before she could ask, her receptionist signaled and a soft voice came from the small button-speaker pinned to the left shoulder of her garment, 'Aurinel Pampas wishes to see you. He has no appointment.'

Insigna grimaced, then remembered that she had sent him after Marlene. She said, 'Let him come in.'

She cast a quick look at the mirror. She could see that her appearance was reasonable. To herself, she seemed to look younger than her forty-two years. She hoped she looked the same way to others.

It seemed silly to worry about her appearance because a seventeen-year-old boy was about to enter, but Eugenia Insigna had seen poor Marlene looking at that boy and she knew what that look portended. It didn't seem to Insigna that Aurinel, who was so fond of his own appearance, would ever think of Marlene, who had never been able to rid herself of her childhood pudginess, in any way other than as an amusing child. Still, if Marlene had to face failure in this, let her not feel that her mother had contributed to that failure in any way and had been anything but charming to the boy.

She'll blame me anyway, thought Insigna with a sigh, as the boy walked in with a smile that had not yet outgrown its adolescent shyness.

'Well, Aurinel,' she said. 'Did you find Marlene?'

'Yes, ma'am. Right where you said she'd be, and I told her you wanted her out of there.'

'And how is she feeling?'

'If you want to know, Dr Insigna - I can't tell if it's depression or something else, but she has a rather funny idea in her head. I don't know that she'd like my telling you about it.'

'Well, I don't like setting spies on her either, but she frequently has strange ideas and she worries me. Please tell me what she said.'

Aurinel shook his head. 'All right, but don't tell her I said anything. This one is really crazy. She said that Earth was going to be destroyed.'

He waited for Insigna to laugh.

She did not. Instead, she exploded. 'What? What made her say that?'

'I don't know, Dr Insigna. She's a very bright kid, you know, but she gets these funny ideas. Or she may have been putting me on.'

Insigna cut in. 'She may have been doing exactly that. She has a strange sense of humor. So listen, I don't want you to repeat this to anyone else. I don't want silly stories to get started. Do you understand?'

'Certainly, ma'am.'

'I'm serious. Not a word.'

Aurinel nodded briskly.

'But thanks for telling me, Aurinel. It was important to do so. I'll speak to Marlene and find out what's bothering her - and I won't let her know you told me.'

'Thank you,' said Aurinel. 'But just one thing, ma'am.'

'What's that?'

'Is Earth going to be destroyed?'

Insigna stared at him, then forced a laugh. 'Of course not! You may go now.'

Insigna looked after him and wished earnestly that she could have managed a more convincing denial.

3

Janus Pitt made an impressive appearance, which had helped him in his rise to power as Commissioner of Rotor. In the early days of the formation of the Settlements, there had been a push for people of no more than average height. There had been thoughts of having a smaller per capita requirement for room and resources. Eventually, the caution had been deemed unnecessary and had been abandoned, but the bias was still there in the genes of the early Settlements and the average Rotorian remained a centimeter or two shorter than the average citizens of later Settlements.

Pitt was tall, though, with iron gray hair, and a long face, and deep blue eyes, and a body that was still in good shape, despite the fact that he was fifty-six.

Pitt looked up and smiled as Eugenia Insigna entered, but felt the usual small surge of uneasiness. There was something always uneasy-making about Eugenia, even wearying. She had these Causes (capital C) that were hard to deal with.

'Thank you for seeing me, Janus,' she said, 'on such short notice.'

Pitt placed his computer on hold, and leaned back in his chair, deliberately producing an air of relaxation.

'Come,' he said, 'there's no formality between us. We go back a long way.'

'And have shared a great deal,' said Insigna.

'So we have,' said Pitt. 'And how is your daughter?'

'It's about her I wish to speak, as a matter of fact. Are we shielded?'

Pitt's eyebrows arched. 'Why shielded? What is there to shield and from whom?'

The very question activated Pitt's realization of the odd position in which Rotor found itself. To all practical purposes, it was alone in the Universe. The Solar System was more than two light-years away, and no other intelligence-bearing worlds might exist within hundreds of light-years or, for all anyone knew, billions of light-years in any direction.

Rotorians might have fits of loneliness and uncertainty, but they were free of any fear of outside interference. Well, almost any fear, thought Pitt.

Insigna said, 'You know what there is to shield. It was you who have always insisted on secrecy.'

Pitt activated the shield and said, 'Are we to take that up again? Please, Eugenia, it's all settled. It was settled when we left fourteen years ago. I know that you brood about it now and then-'

'Brood about it? Why not? It's my star,' and her arm flailed outward as if in the direction of Nemesis. 'It's my responsibility.'

Pitt's jaw tightened. Do we have to go through all this again? he thought.

Aloud, he said, 'We're shielded. Now, what's bothering you?'

'Marlene. My daughter. Somehow she knows.'

'Knows what?'

'About Nemesis and the Solar System.'

'How could she know? Unless you've told her?'

Insigna spread her arms helplessly. 'Of course I didn't tell her, but I don't have to. I don't know how it is, but somehow Marlene seems to hear and see everything. And from the little things she hears and sees, she works things out. She's always been able to do it, but in the last year it's grown much worse.'

'Well then, she guesses, and sometimes she makes lucky guesses. Tell her she's wrong, and see that she doesn't talk about it.'

'But she's already told a young man, who came to tell me. That's how I know. Aurinel Pampas. He's a friend of the family.'

'Ah yes. I'm aware of him - somewhat. Simply tell him not to listen to fantasies made up by a little girl.'

'She's not a little girl. She's fifteen.'

'To him, she's a little girl, I assure you. I said I'm aware of the young man. I'm under the impression he's pushing adulthood very hard and I remember, when I was his age, that fifteen-year-old girls were beneath contempt, especially if they were-'

Insigna said bitterly, 'I understand. Especially if they are short, plump, and plain. Does it matter that she's highly intelligent?'

'To you and to me? Certainly. To Aurinel, certainly not. If necessary, I'll talk to the boy. You talk to Marlene. Tell her the idea is ridiculous, that it isn't true, and that she must not spread disturbing fairy tales.'

'But what if it is true?'

'That's beside the point. Look, Eugenia, you and I have concealed this possibility for years, and it would be better if we continued to conceal it. If it gets around, it will be exaggerated, and there will be rising sentiment about the matter - useless sentiment. It will only distract us from the job that has occupied our time ever since we left the Solar System, and which will continue to occupy us for generations, perhaps.'

She looked at him - shocked, unbelieving. 'Have you really no feeling for the Solar System, for Earth, the world on which humanity originated?'

'Yes, Eugenia, I have all sorts of feelings. But they're visceral and I can't let them sway me. We left the Solar System because we thought it was time for humanity to spread outward. Others, I'm sure, will follow; maybe they are already doing so. We have made humanity a Galactic phenomenon and we mustn't think in terms of a single planetary system any more. Our job is here.'

They stared at each other, then Eugenia said, with a touch of hopelessness, 'You'll talk me down again. You've talked me down for so many years.'

'Yes, but next year I'll have to again, and the year after. You won't stay down, Eugenia, and you tire me. The first time should have been enough.' And he turned away, back to his computer.