When they reached her, she looked at them quietly and amazed them by asking, ‘What's wrong?’

No-one had answered. A hand reached out for her elbow and she whipped away.

‘Don't touch me,’ she said. ‘I'll go to the Dome, if that's what you want, but I can walk.’

And she had walked quietly back with them. She was quite self-possessed.

Eugenia Insigna, lips dry and pale, was trying not to seem distraught. ‘What happened out there, Marlene?’

Marlene said, her dark eyes wide and unfathomable, ‘Nothing. Nothing at all.’

‘Don't say that. You were running and screaming.’

‘I may have been for a little while, but just for a little while. You see, it was quiet, so quiet, that after a while I felt as though I must be deaf. Just silence, you know. So I stamped my feet and ran just to hear the noise, and I screamed-’

‘Just to hear the noise of it?’ asked Insigna, frowning.

‘Yes, Mother.’

‘Do you expect me to believe that, Marlene? Because I don't. We picked up the screams and those were not the screams of making noise. Those were screams of terror. Something had frightened you.’

‘I told you. The silence. The possibility of deafness.’ Insigna turned to D'Aubisson. ‘Isn't it possible, Doctor, that if you don't hear anything, anything at all, and if you're used to hearing things all the time, then your ears might just imagine they're hearing something so they can feel useful?’

D'Aubisson forced a thin smile. ‘That's a colorful way of putting it, but it is true that sensory deprivation can produce hallucinations.’

‘That disturbed me, I suppose. But after I heard my own voice and my own footsteps, I quieted down. Ask the two guards who came to get me. I was perfectly calm when they arrived, and I followed them into the Dome with no trouble. Ask them, Uncle Siever.’

Genarr nodded. ‘They've told me this. And we watched it happen, besides. Very well, then. That's it.’

‘That's not it at all,’ said Insigna, her face still white - from fright or anger or both. ‘She's not going out any more. The experiment is finished.’

‘No, Mother,’ said Marlene, outraged. D'Aubisson raised her voice, as though to forestall any angry clash of wills between mother and daughter. She said, ‘The experiment is not finished, Dr Insigna. Whether she goes out again or not is beside the point. We still have to deal with the consequences of what has happened.’

‘What do you mean?’ demanded Insigna.

‘I mean, it's all very well to talk about imagining voices because the ear is not accustomed to silence, but surely another possible reason for imagined voices is the onset of a certain mental instability.’

Insigna looked stricken.

Marlene said loudly, ‘Do you mean the Erythro Plague?’

‘I don't mean that particularly, Marlene,’ said D'Aubisson. ‘We don't have any evidence; only a possibility. So we need another brain scan. It's for your own good.’

‘No,’ said Marlene.

‘Don't say no,’ said D'Aubisson. ‘It's a must. We have no choice. It's something we'll have to do.’

Marlene looked at D'Aubisson out of her dark and brooding eyes. She said, ‘You're hoping I have the Plague. You want me to have the Plague.’

D'Aubisson stiffened, and her voice cracked. ‘That's ridiculous. How dare you say such a thing?’

But it was Genarr, now, who was staring at D'Aubisson. He said, ‘Ranay, we've discussed this little point about Marlene, and if she says you want her to have the Plague, you must have given yourself away in some way. That is, if Marlene is serious and isn't just saying it out of fright or anger.’

‘I'm serious,’ said Marlene. ‘She was just bubbling with hopeful excitement.’

‘Well, Ranay,’ said Genarr a little more coldly. ‘Are you?’

‘I see what the girl means,’ said D'Aubisson, frowning. ‘I have not studied a fresh case of advanced Plague in years. And in the days when I did, when the Dome was primitive and had just been established, I had had virtually no appropriate devices with which to study it. Professionally, I would greatly welcome a chance to make a thorough study of a case of the Plague with modern techniques and instrumentation, to find out, perhaps, the true cause, the true cure, the true prevention. It's a reason for excitement, yes. It is a professional excitement that this young woman, unable to read minds, and without experience in such things, interprets as simple joy. It isn't simple.’

‘It may not be simple,’ said Marlene, ‘but it's malevolent. I'm not mistaken in that.’

‘You are mistaken. The brain scan must and will take place.’

‘It will not ,’ said Marlene, practically shouting. ‘You'll have to force me or sedate me, and then it won't be valid.’

Insigna said, her voice shaking, ‘I don't want anything done against her will.’

‘This is something that goes beyond what she wills or does not will-’ began D'Aubisson, and then staggered back with her hand to her abdomen.

Genarr said automatically, ‘What's the matter?’

Then, without waiting for an answer, leaving it to Insigna to lead D'Aubisson to the nearest sofa and to persuade her to lie down, he turned to Marlene and said hurriedly, ‘Marlene, agree to the test.’

‘I don't want to. She'll say I have the Plague.’

‘She won't. I guarantee that. Not unless you really do.’

‘I don't.’

‘I'm sure you don't, and the brain scan will prove it. Trust me, Marlene. Please.’

Marlene looked from Genarr to D'Aubisson and back again. ‘And I can go back out on Erythro again?’

‘Of course. As often as you wish. If you're normal - and you're sure you're normal, aren't you?’

‘Sure as anything.’

‘Then the brain scan will prove it.’

‘Yes, but she'll say I can't go out again.’

‘Your mother?’

‘And the doctor.’

‘No, they won't dare stop you. Now, just say you'll allow the brain scan.’

‘All right. She can have it.’

Ranay D'Aubisson struggled to her feet.

D'Aubisson studied the computerized analysis of the brain scan carefully while Siever Genarr watched.

‘A curious scan,’ muttered D'Aubisson.

‘We knew that to begin with,’ said Genarr. ‘She's a strange young woman. The point is there's no change?’

‘None,’ said D'Aubisson.

‘You sound disappointed.’

‘Don't start that again, Commander. There's a certain professional disappointment. I would like to study the condition.’

‘How do you feel?’

‘I just told you-’

‘I mean, physically. That was a strange collapse you had yesterday.’

‘It wasn't a collapse. It was nervous tension. I'm not often accused of wanting someone to be seriously ill - and of having it apparently believed .’

‘What happened? An attack of indigestion?’

‘Could be. Abdominal pains, in any case. And dizziness.’

‘Does that often happen to you, Ranay?’

‘No, it doesn't,’ she said sharply, ‘Neither am I accused of unprofessional behavior often.’

‘Just an excitable young woman. Why did you take it so seriously?’

‘Do you mind if we change the subject? She does not have any signs of brain scan change. If she was normal before, then she is still normal.’

‘In that case, is it your professional opinion that she may continue to explore Erythro?’

‘Since she has not been affected, apparently, I have no grounds on which to forbid her.’

‘Are you willing to go beyond that and send her out?’

D'Aubisson's attitude grew hostile. ‘You know that I've been to see Commissioner Pitt.’ It did not sound like a question.

‘Yes, I know,’ said Genarr quietly.

‘He has asked me to head a new project designed to study the Erythro Plague, and there will be a generous appropriation toward that study.’

‘I think that is a good idea and that you are a thoroughly good choice to head the study.’

‘Thank you. However, he did not appoint me Commander in your place. Therefore, it is up to you, Commander, to decide whether Marlene Fisher can be allowed to go out on Erythro. I will confine myself to giving her a brain scan if signs of abnormality show up.’

‘I intend to give Marlene permission to explore Erythro freely whenever she wishes. May I have your concurrence in that?’

‘Since you have my medical opinion that she does not have the Plague, I will make no attempt to stop you, but the order to do so will have to be yours alone. If anything must be put into writing, you will have to sign it yourself.’

‘But you won't try to stop me.’

‘I have no reason to.’

Dinner was over and soft music played in the background. Siever Genarr, who had carefully talked of other things to an uneasy Eugenia Insigna, finally said, ‘The words are the words of Ranay D'Aubisson, but the force behind them is that of Janus Pitt.’

Insigna's look of uneasiness deepened. ‘Do you really think that?’

‘Yes, I do - and you should. You knew Janus better than I do, I think. It's too bad. Ranay is a competent doctor, has a profound mind, and is a good person, but she's ambitious - as we all are, one way or another - and she can therefore be corrupted. She really wants to go down in history as the one who defeated the Erythro Plague.’

‘And she would be willing to risk Marlene to do it?’

‘Not willing in the sense that she wants to, or is eager to, but willing in the sense of - well, if there's no other way.’

‘But there must be other ways. To send Marlene into danger, as an experimental device, is monstrous.’

‘Not from her standpoint, and certainly not from Pitt's. One mind is well lost if it rescues a world and makes it a fit human habitation for millions. It's a hardhearted way of looking at it, but future generations might make a heroine out of Ranay for being hardhearted, and agree with her that one mind was well lost, or a thousand - if that's what it would take.’

‘Yes, if it's not their minds.’

‘Of course. All through history, human beings have been ready to make sacrifices at the expense of other people. Certainly, Pitt would. Or don't you agree?’

‘About Pitt. Yes, I do,’ said Insigna energetically. ‘To think that I worked with him all those years.’

‘Then you know that he would view this in a very moralistic sense. “The greatest good for the greatest number,” he would say. Ranay admits that she talked to him on her recent visit to Rotor, and I'm as positive that that's what he said to her, in one form of words or another, as that I am sitting in this chair.’