Siever Genarr opened his eyes slowly and blinked at the light. He had a little trouble focusing at first and couldn't quite make out whatever filled his vision.

The image sharpened slowly and soon Genarr recognized Ranay D'Aubisson, Chief Neurophysicist of the Dome.

Genarr said in a weak voice, ‘Marlene?’

D'Aubisson looked grim. ‘She seems well. It's you I'm concerned about right now.’

A pang of apprehension made its way through Genarr's vitals and he tried to drown it with his sense of black humor. He said, ‘I must be worse off than I thought if the Angel of the Plague is here.’

Then, as D'Aubisson said nothing, Genarr asked sharply, ‘Am I?’

She seemed to come to life. Tall and angular, she bent over him, the fine wrinkles about her piercing blue eyes becoming more prominent as she squinted at him.

‘How do you feel?’ she asked, answering no questions.

‘Tired. Very tired. All right, otherwise. I think?’ The rising inflection served to repeat his earlier question.

She said, ‘You've been sleeping for five hours.’ She was still not answering.

Genarr groaned. ‘I'm tired anyway. And I have to go to the bathroom.’ He began to struggle into a sitting position.

At D'Aubisson's signal a young man approached rapidly. Respectfully, he placed his hand under Genarr's elbow and was indignantly shaken off.

D'Aubisson said, ‘Please let yourself be helped. We have made no diagnosis yet.’

When Genarr was back in bed ten minutes later, he said ruefully, ‘No diagnosis. Have you made a brain scan?’

‘Yes, of course. Instantly.’

‘Well?’

She shrugged. ‘We found nothing of importance, but you were asleep. We will take another when you're awake. And you must be observed in other ways.’

‘Why? Isn't the brain scan enough?’

Her gray eyebrows rose. ‘Do you think it is?’

‘No games. What are you getting at? Say it straight out. I'm not a child.’

D'Aubisson sighed. ‘The cases of the Plague we have had showed interesting features on brain scan, but we were never able to compare it with the pre-Plague standard because none of the sufferers had been scanned prior to onset. By the time we set up a routine and universal brain scanning program for all people in the Dome, there were no longer any unmistakable cases of the Plague. Did you know this?’

‘Don't lay traps for me,’ said Genarr pettishly. ‘Of course I knew of it. Do you think my memory is gone? I deduce, then - I can still deduce, too, you know - that although you have my scan of earlier days and can compare it with the scan you just took, you found nothing of significance. Is that it?’

‘You obviously do not have anything remarkably wrong, but we might have something we would consider a subclinical situation.’

‘If you find nothing ?’

‘We might not notice a subtle change if we're not specifically looking for it. After all, you collapsed and you are not ordinarily given to collapsing, Commander.’

‘Take another scan now that I'm awake, then, and if it's something so subtle it escapes you, then I'll live with it. But tell me about Marlene. Are you sure she's well?’

‘I said she seems well, Commander. Unlike you, she showed no abnormality of behavior. She did not collapse.’

‘And is she safely inside the Dome?’

‘Yes, she brought you in herself, just before you fell unconscious. Don't you remember?’

Genarr flushed, and mumbled something.

D'Aubisson's look grew sardonic. ‘Suppose you tell us exactly what do you remember, Commander. Tell us everything. Any of it may be important.’

Genarr's discomfort increased as he tried to remember. It seemed a long time ago and the edges were blurred, very much as though it were a dream he was trying to recall.

‘Marlene was taking off her E-suit.’ Then, weakly, ‘Wasn't she?’

‘Quite. She came in without it and we had to send someone out there to retrieve it.’

‘Well, I tried to stop her, of course, when I noticed what she was doing. Dr Insigna called out, I remember, and that alerted me. Marlene was a distance away from me, by the stream. I tried to call out, but, in the shock of the situation I couldn't manage to make a sound just at first. I tried to get to her quickly, to - to-’

‘Run to her,’ put in D'Aubisson.

‘Yes, but - but-’

‘But you found you couldn't run. You were almost in a state of paralysis. Am I correct?’

Genarr nodded. ‘Yes. Rather. I tried to run, but - did you ever have one of those nightmares when you are pursued and somehow you can't manage to make yourself run?’

‘Yes. We all have those. It usually comes when we have managed to tangle our arms or legs in the bedclothes.’

‘It felt like a dream. I managed to get my voice, at last, and shouted at her, but without the E-suit, she couldn't hear me, I'm sure.’

‘Did you feel faint?’

‘Not really. Just helpless and confused. As though it were not even any use in trying to run. Then Marlene saw me and ran toward me. She must somehow have recognized I was in trouble.’

‘She didn't seem to have any trouble running. Is that right?’

‘I wasn't aware that she was. She seemed to reach me. Then we- I'll be honest, Ranay. I don't remember after that.’

‘You came into the Dome together,’ said D'Aubisson calmly. ‘She was helping you, holding you up. And once in the Dome, you collapsed and now - here you are.’

‘And you think I have the Plague.’

‘I think you experienced something abnormal, but I can find nothing in your brain scan, and I am puzzled. There you have it.’

‘It was the shock of seeing Marlene in danger. Why should she be taking off her E-suit if she weren't-’ He stopped abruptly.

‘If she weren't succumbing to the Plague. Is that it?’

‘The thought crossed my mind.’

‘But she seems fine. Would you like to sleep some more?’

‘No. I'm awake. Take another brain scan and see to it that it comes out negative because I feel much better now that I have the story off my chest. And then I'm going about my business, you harpy.’

‘Even if the brain scan is apparently normal, Commander, you'll stay in bed for at least twenty-four hours. For observation, you understand.’

Genarr groaned theatrically. ‘You can't do that. I can't lie here and stare at the ceiling for twenty-four hours.’

‘You won't have to. We can set up a viewing stand for you, so that you can read a book or enjoy holovision. You can even have a visitor or two.’

‘I suppose the visitors will be observing me, too.’

‘It's conceivable they may be questioned on the matter. And now we'll set up the brain scan equipment again.’ She turned away, then turned back with a smile that softened slightly at the edges. ‘It's very possible you're all right, Commander. Your reactions seem normal to me. But we must be sure, mustn't we?’

Genarr grunted, and when D'Aubisson turned again and walked away, he made a face at her straight back. That, he decided, was a normal reaction, too.

When Genarr opened his eyes again, it was to see Eugenia Insigna gazing at him sadly.

He looked surprised and began to sit up. ‘Eugenia!’

She smiled at him, but that did not make her face look less sad.

She said, ‘They said I could come in, Siever. They said you were all right.’

Genarr felt a wave of relief. He knew he was all right, but it was nice to hear that his opinion was confirmed.

He said with bravado, ‘Of course I am. Brain scan normal, asleep. Brain scan normal, awake. Brain scan normal, for ever. But how's Marlene?’

‘Her brain scan is perfectly normal, too.’ Even that did not lighten her mood.

‘As you see,’ said Genarr, ‘I was Marlene's canary, as I had promised. I was affected by whatever it was before she was.’ And then his mood changed. It was no time for banter.

He said, ‘Eugenia, how can I excuse myself to you? I wasn't watching Marlene to begin with, and I was too paralyzed with horror to do anything afterward. I failed completely, and did so after telling you with such confidence that I would take care of her. Honestly, I have no excuse.’

Insigna was shaking her head. ‘No, Siever. It was in no way your fault. I'm so glad she brought you in.’

‘Not my fault?’ Genarr felt dumbfounded. Of course it was his fault.

‘Not at all. There's something much worse than Marlene foolishly removing her suit, or you being unable to act quickly. Much worse. I'm sure of it.’

Genarr felt himself turning cold. What's much worse? he thought. ‘What are you trying to tell me?’

He swung himself out of bed and suddenly became aware of his bare legs and of the totally inadequate gown he was wearing. He hastily draped the light blanket around himself.

He said, ‘Please sit down and tell me. Is Marlene all right? Are you hiding something about her?’

Insigna sat down and looked solemnly at Genarr. ‘They say she's all right. The brain scan is entirely norm al. Those who know about the Plague say she shows no symptoms.’

‘Well then, why are you sitting there as though it's the end of the world?’

‘I think it is, Siever. Of this one.’

‘What does that mean?’

‘I can't explain. I can't reason it out. You have to talk to Marlene to understand. She's going her own way, Siever. She's not upset over what she did. She insists that she cannot properly explore Erythro - experience Erythro is the phrase she uses - with the E-suit on and she has no intention of wearing one any longer.’

‘In that case, she won't go out.’

‘Oh, but Marlene says she will. Quite confidently. Whenever she wishes, she says. And alone. She blames herself for having let you come with her. She's not callous over what happened to you, you see. Over that, she is upset. And she was glad she reached you in time. Really, there were tears in her eyes when she talked about what might have happened if she hadn't walked you into the Dome in time.’

‘Doesn't that make her feel insecure?’

‘No. That's the oddest part of it. She's now sure that you were in danger, that anyone would have been in danger. But not she. She is so positive , Siever, I could-’ She shook her head, then muttered, ‘I don't know what to do.’

‘She's a positive girl by nature, Eugenia. You must know that better than I do.’

‘Not this positive. It's as though she knows we can't stop her.’