'Well, it looks as though we'll have to call for a volunteer,' Marlowe exclaimed. 'Who is for the first sitting?'

There was a long pause that almost grew into an embarra.s.sed silence. At length Weichart moved forward.

'If everybody else is too bashful, I guess I'm willing to be first guinea pig.'

McNeil gave him a long look.

'There's just one point, Weichart. You realize that this business may carry with it an element of danger? You're quite clear on that, I suppose?'

Weichart laughed.

'Don't worry about that. This won't be the first time I've spent a few hours watching cathode ray tubes.'

' Very well, then. If you're willing to try, by all means take the chair.'

'Be careful about the chair, Dave. Maybe Harry's wired it up specially for you,' grinned Marlowe.

Shortly after this, lights began to flash on the tubes.

'Joe's starting up,' said Leicester.

Whether there was any pattern a.s.sociated with the lights was difficult to tell.

'What's he saying, Dave? Getting the message?' asked Barnett.

'Nothing I can understand,' remarked Weichart, throwing a leg over his chair. 'Looks a pretty random unintelligible jumble. Still I'll keep on trying to make some sense out of it.'

Time dragged on in a desultory way. Most of the company lost interest in the flickering lights. Multi-way conversations broke out and Weichart was left to a lonely vigil. At length Marlowe asked him: 'How's it going, Dave?'

No answer.

'Hey, Dave, what's going on?'

Still no answer.

'Dave!'

Marlowe and McNeil came one to each side of Weichart's chair.

'Dave, why don't you answer?'

McNeil touched him on the shoulder, but there was still no response. They watched his eyes, fixed on first one group of tubes, then flicking quickly to another.

'What is it, John?' asked Kingsley.

'I think he's in some hypnotic state. He doesn't seem to be noticing any sense data except from the eyes, and they seem to be directed only at the tubes.'

'How could it have happened?'

'A hypnotic condition induced by visual means is not by any means unknown.'

'You think it was deliberately induced?'

'It seems more than likely. I can scarcely believe it could have happened by accident. And watch the eyes. See how they move. This is not a chance business. It looks purposive, very purposive.'

'I wouldn't have said Weichart was a likely subject for a hypnotist.'

'Nor would I. It looks extremely formidable, and very singular.'

'What do you mean?' asked Marlowe.

'Well, although an ordinary human hypnotist might use some visual method for inducing a hypnotic state, he'd never use a purely visual medium for conveying information. A hypnotist talks to a subject, he conveys meaning with words. But there are no words here. That's why it is d.a.m.n strange.'

'It's funny you should have warned Dave. Had you any idea this would happen, McNeil?'

'No, not in detail, of course. But recent developments in neurophysiology have shown up some extremely queer effects when lights are flashed in the eyes at rates that match closely with scanning speeds in the brain. And then it was obvious that the Cloud couldn't do what it said it would do unless something pretty remarkable happened.'

Kingsley came up to the chair.

'Do you think we ought to do something? Pull him away, perhaps. We could easily do that.'

'I wouldn't advise it, Chris. He'd probably struggle violently and it might be dangerous. Best on the whole to leave him. He went into it with his eyes open, literally and figuratively. I'll stay with him of course. The rest of you ought to clear out, though. Leave somebody who can carry a message Stoddard will do and then I can call you if anything crops up.'

'All right. We'll be ready in case you need us,' agreed Kingsley.

n.o.body really wanted to leave the lab, but it was realized that McNeil's suggestion had much to recommend it.

'Wouldn't do to have the whole party hypnotized,' remarked Barnett. 'I only hope old Dave will be all right,' he added anxiously.

'We could, I suppose, have switched the gear off. But McNeil seemed to think that might cause trouble. Shock, I suppose.' This from Leicester.

'It beats me as to what information Dave can be getting,' said Marlowe.

'Well, we shall know soon enough, I expect. I don't suppose the Cloud will go on for many hours. It's never done so in the past,' observed Parkinson.

But the transmission turned out to be a long one. As the hours advanced the members of the company retired severally to bed.

Marlowe expressed the general opinion: 'Well, we're not doing Dave any good, and we're missing sleep. I think I shall try to s.n.a.t.c.h an hour or two.'

Kingsley was woken by Stoddard.

'Doctor wants you, Dr Kingsley.'

Kingsley found that Stoddard and McNeil had managed to move Weichart to one of the bedrooms, so evidently the business was finished, at any rate for the time being.

'What is it, John?' he asked.

'I don't like the position, Chris. His temperature is rising rapidly. There isn't much point in your going in to see him. He's not in a coherent state, and not like to be with a temperature at 104.'

'Have you any idea what's wrong?'

'I obviously can't be sure, because I've never encountered a case like this before. But if I didn't know what had happened, I'd have said Weichart was suffering from an inflammation of brain tissue.'

'That's very serious, isn't it?'

'Extremely so. There's very little that any of us can do for him, but I thought you'd like to know.'

'Yes, of course. Have you any idea what may have caused it?'

'Well, I'd say too high a rate of working, too great a demand of the neurological system on all the supporting tissues. But again it's only an opinion.'

Weichart's temperature continued to rise during the day, and in the late afternoon he died.

For professional reasons McNeil would have liked to perform an autopsy, but out of consideration for the feelings of the others he decided against it. He kept his own company, thinking gloomily that somehow he ought to have foreseen the tragedy and taken steps to prevent it. But he had not foreseen it, nor did he foresee the events that were to follow. The first warning came from Ann Halsey. She was in a hysterical condition when she accosted McNeil.

'John, you must do something. It's Chris. He's going to kill himself.'

'What!'

'He's going to do the same as Dave Weichart. I've been trying for hours to persuade him not to, but he won't take any notice of me. He says he's going to tell the Thing to go slower, that it was the speed that killed Dave. Is that true?'

'It might be. I don't know for sure, but it's quite possible.'

'Tell me frankly, John, is there any chance?'

'There might be. I just don't know enough to offer any definite opinion.'

'Then you must stop him!'

'I'll try. I'll go along and talk to him straight away. Where is he?'

'In the labs. Talking's no use. He'll have to be stopped by force. It's the only way.'

McNeil made straight for the transmitting lab. The door was locked, so he hammered hard on it. Kingsley's voice came faintly.

'Who is it?'

'It's McNeil. Let me in, will you?'

The door opened and McNeil saw as he stepped inside the room that the equipment was switched on.

'Ann has just been and told me, Chris. Don't you think it's just a little crazy, especially within a few hours of Weichart's death?'

'You don't suppose I like this idea, do you, John? I can a.s.sure you that I find life just as pleasant as anyone else. But it's got to be done and it's got to be done now. The chance will have gone in not much more than a week, and it's a chance that we humans simply can't afford to miss. After poor Weichart's experience it wasn't likely that anyone else would come forward, so I've got to do it myself. I'm not one of those courageous fellows who can contemplate danger placidly. If I've got a sticky job to do I prefer to get on with it straight away saves thinking about it.'

'This is all very well, Chris, but you're not going to do anybody any good by killing yourself.'

'That's absurd, and you know it. The stakes in this business are very high, they're so high as to be worth playing for, even if the chance of winning isn't very great. That's point number one. Point number two is that maybe I stand a pretty fair chance. I've already been on to the Cloud, telling it to go much slower. It has agreed to do so. You yourself said that might avoid the worst of the trouble.'

'It might. Then again it might not. Also, if you avoid Weichart's trouble, there may be other dangers that we know nothing about.'

'Then you'll know about them from my case, which will make it easier for someone else, just as it is a little easier for me than it was for Weichart. It's no good, John. I'm quite resolved, and I'm going to start in a few more minutes.'

McNeil saw that Kingsley was beyond persuasion.

'Well, anyway,' he said, 'I take it you'll have no objection to my staying here. It took about ten hours with Weichart. With you it's going to take longer. You'll need food in order to keep a proper blood supply to your brain.'

'But I can't stop off to eat, man! Do you realize what this means? It means learning a whole new field of knowledge, learning in just one lesson!'

'I'm not suggesting that you stop off for a meal. I'm suggesting that I give you injections from time to time. Judging by Weichart's condition, you won't feel it.'

'Oh, I am not worried about that. Inject away if it makes you happy. But sorry, John, I must get down to this business.'

It is unnecessary to repeat the following events in detail, since they followed much the same pattern in Kingsley's case as they had with Weichart. The hypnotic condition lasted longer however, nearly two days. At the end he was carried to bed under McNeil's direction. During the next few hours symptoms developed that were alarmingly similar to those of Weichart. Kingsley's temperature rose to 102... 103... 104. But then it steadied, stopped, and, as hour followed hour, fell slowly. And as it fell, the hopes rose of those round his bed, notably McNeil and Ann Halsey who never left him, and Marlowe, Parkinson, and Alexandrov.

Consciousness returned about thirty-six hours after the end of the Cloud's transmission. For some minutes an uncanny series of expressions flitted across Kingsley's face: some were well known to the watchers, others were wholly alien. The full horror of Kingsley's condition developed suddenly. It began with an uncontrolled twitching of the face, and with incoherent muttering. This quickly developed into shouting and then into wild screams.

'My G.o.d, he's in some sort of fit,' exclaimed Marlowe.

At length the attack subsided under an injection from McNeil, who thereupon insisted on being left alone with the demented man. Throughout the day the others from time to time heard m.u.f.fled cries which then died away under repeated injections.

Marlowe managed to persuade Ann Halsey to take a walk with him in the afternoon. It was the most difficult walk in his experience.

In the evening he was sitting in his room gloomily when McNeil walked in, a McNeil gaunt and hollow-eyed.

'He's gone,' announced the Irishman 'My G.o.d, what a dreadful tragedy, an unnecessary tragedy.'

'Aye, man, a bigger tragedy than you realize.'

'What d'you mean?'

'I mean it was touch and go whether he saved himself. In the afternoon he was sane for nearly an hour. He told me what the trouble was. He fought it down and as the minutes pa.s.sed I thought he was going to win out. But it wasn't to be. He got into another attack and it killed him.'

'But what was it?'

'Something obvious, that we ought to have foreseen. What we didn't allow for was the tremendous quant.i.ty of new material which the cloud seems able to impress on the brain. This of course means that there must be widespread changes of the structure of a ma.s.s of electrical circuits in the brain, changes of synaptic resistances on a big scale, and so on.'

'You mean it was a sort of gigantic brain-washing?'

'No, it wasn't. That's just the point. There was no washing. The old methods of operation of the brain were not washed out. They were left unimpaired. The new was established alongside the old, so that both were capable of working simultaneously.'

'You mean that it was as if my knowledge of science were suddenly added to the brain of an ancient Greek.'

'Yes, but perhaps in a more extreme form. Can you imagine the fierce contradictions that would arise in the brain of your poor Greek, accustomed to such notions as the Earth being the centre of the Universe and a hundred and one other such anachronisms, suddenly becoming exposed to the blast of your superior knowledge?'

'I suppose it would be pretty bad. After all we get quite seriously upset if just one of our cherished scientific ideas turns out wrong.'

'Yes, think of a religious person who suddenly loses faith, which means of course that he becomes aware of a contradiction between his religious and his non-religious beliefs. Such a person often experiences a severe nervous crisis. And Kingsley's case was a thousand times worse. He was killed by the sheer violence of his nervous activity, in a popular phrase by a series of unimaginably fierce brain-storms.'