When the party rea.s.sembled it was obvious at a glance how things had gone. Marlowe took a cup of coffee from Parkinson.

'Thanks. Well, that's that. Chris was right and Dave was wrong. Now I suppose we must get down to trying to decide what it means.'

'Your move, Chris,' said Leicester.

'Let's suppose then that my hypothesis is right, that our own transmissions are producing a marked effect on the atmospheric ionization.'

Ann Halsey handed Kingsley a mug of coffee.

'I'd be a lot happier if I knew what ionization meant. Here, drink this.'

'Oh, it means that the outer parts of the atoms are stripped away from the inner parts.'

'And how does this happen?'

'It can happen in many ways, by an electrical discharge, as in a flash of lightning, or in a neon tube the sort of strip lighting we've got here. The gas in these tubes is being partially ionized.'

'I suppose energy is the real difficulty? That your transmissions have far too little power to produce this rise of ionization?' said McNeil.

'That's right,' answered Marlowe. 'It's completely impossible that our transmissions should be the primary cause of the fluctuations in the atmosphere. My G.o.d, they'd need a fantastic amount of power.'

'Then how can Kingsley's hypothesis be right?'

'Our transmissions are not the primary cause, as Geoff says. That's wholly impossible. I agree with Weichart there. My hypothesis is that our transmissions are acting as a trigger, whereby some very large source of power is released.'

'And where, Chris, do you suppose this source of power is to be located?' asked Marlowe.

'In the Cloud, of course.'

'But surely it's quite fantastic to imagine that we can cause the Cloud to react in such a fashion, and to do it with such reproducibility? You'd have to suppose that the Cloud was equipped with a sort of feedback mechanism,' argued Leicester.

'On the basis of my hypothesis that's certainly a correct inference.'

'But don't you see, Kingsley, that it's utterly mad?' Weichart exclaimed.

Kingsley looked at his watch.

'It's almost time to go and try again, if anyone wants to. Does anyone want to?'

'In heaven's name, no!'said Leicester.

'Either we go or we stay. And if we stay it means that we accept Kingsley's hypothesis. Well, boys, do we go or do we stay?' remarked Marlowe.

'We stay,' said Barnett. 'And we see how the argument goes. We've got as far as some sort of a feedback mechanism in the Cloud, a mechanism set to churn out an enormous amount of power as soon as it receives a trickle of radio emission from outside itself. The next step, I suppose, is to speculate on how the feedback mechanism works, and why it works as it does. Anybody got any ideas?'

Alexandrov cleared his throat. Everybody waited to catch one of his rare remarks.

'b.a.s.t.a.r.d in Cloud. Said so before.'

There were wide grins and a giggle from Yvette Hedelfort. Kingsley, however, remarked quite seriously: 'I remember you did. Were you serious about it, Alexis?'

'Always serious, d.a.m.n it,' said the Russian.

'Without frills, what exactly do you mean, Chris?' someone asked.

'I mean that the Cloud contains an intelligence. Before anybody starts criticizing, let me say that I know it's a preposterous idea and I wouldn't suggest it for a moment if the alternative weren't even more outrageously preposterous. Doesn't it strike you how often we've been wrong about the behaviour of the Cloud?'

Parkinson and Ann Halsey exchanged an amused glance.

'All our mistakes have a certain hallmark about them. They're just the sort of mistake that it'd be natural to make if, instead of the Cloud being inanimate, it were alive.'

Close Reasoning

It is curious in how great a degree human progress depends on the individual. Humans, numbered in thousands of millions, seem organized into an ant-like society. Yet this is not so. New ideas, the impetus of all development, come from individual people, not from corporations or states. New ideas, fragile as spring flowers, easily bruised by the tread of the mult.i.tude, may yet be cherished by the solitary wanderer.

Among the vast host that experienced the coming of the Cloud, none except Kingsley arrived at a coherent understanding of its real nature, none except Kingsley gave the reason for the visit of the Cloud to the solar system. His first bald statement was greeted with outright disbelief even by his fellow scientists Alexandrov excepted.

Weichart was frank in his opinion.

'The whole idea is quite ridiculous,' he said.

Marlowe shook his head.

'This comes of reading science fiction.'

'No b.l.o.o.d.y fiction about Cloud coming straight for dam' Sun. No b.l.o.o.d.y fiction about Cloud stopping. No b.l.o.o.d.y fiction about ionization,' growled Alexandrov.

McNeil, the physician, was intrigued. The new development was more in his line than transmitters and aerials.

'I'd like to know, Chris, what you mean in this context by the word "alive".'

'Well, John, you know better than I do that the distinction between animate and inanimate is more a matter of verbal convenience than anything else. By and large, inanimate matter has a simple structure and comparatively simple properties. Animate or living matter on the other hand has a highly complicated structure and is capable of very involved behaviour. When I said the Cloud may be alive I meant that the material inside it may be organized in an intricate fashion, so that its behaviour and consequently the behaviour of the whole Cloud is far more complex than we previously supposed.'

'Isn't there an element of tautology there?' from Weichart.

'I said that words such as "animate" and "inanimate" are only verbal conveniences. If they're pushed too far they do appear tautological. In more scientific terms I expect the chemistry of the interior of the Cloud to be extremely complicated complicated molecules, complicated structures built out of molecules, complicated nervous activity. In short I think the Cloud has a brain.'

'A dam' straightforward conclusion,' nodded Alexandrov.

When the laugh had subsided, Marlowe turned to Kingsley.

'Well, Chris, we know what you mean, at any rate we know near enough. Now let's have your argument. Take your time. Let's have it point by point, and it'd better be good.'

'Very well then, here goes. Point number one, the temperature inside the Cloud is suited to the formation of highly complicated molecules.'

'Right! First point to you. In fact, the temperature is perhaps a little more favourable than it is here on the Earth.'

'Second point, conditions are favourable to the formation of extensive structures built out of complicated molecules.'

'Why should that be so?' asked Yvette Hedelfort.

'Adhesion on the surface of solid particles. The density inside the Cloud is so high that quite large lumps of solid material probably mostly ordinary ice are almost certainly to be found inside it. I suggest that the complicated molecules get together when they happen to stick to the surfaces of these lumps.'

'A very good point, Chris,' agreed Marlowe.

'Sorry, I don't pa.s.s this round.' McNeil was shaking his head. 'You talk of complicated molecules being built up by sticking together on the surface of solid bodies. Well, it won't do. The molecules out of which living material is made contain large stores of internal energy. Indeed the processes of life depend on this internal energy. The trouble with your sticking together is that you don't get energy into the molecules that way.'

Kingsley seemed unperturbed.

'And from what source do the molecules of living creatures here on the Earth get their internal supplies of energy?' he asked McNeil.

'Plants get it from sunlight, and animals get it from plants, or from other animals of course. So in the last a.n.a.lysis the energy always comes from the Sun.'

'And where is the Cloud getting energy from now?'

The tables were turned. And as neither McNeil nor anyone else seemed disposed to argue, Kingsley went on: 'Let's accept John's argument. Let's suppose that my beast in the Cloud is built out of the same sort of molecules that we are. Then the light from some star is required in order that the molecules be formed. Well, of course starlight is available far out in the s.p.a.ce between the stars, but it's very feeble. So to get a really strong supply of light the beast would need to approach close to some star. And that's just what the beast has done!'

Marlowe became excited.

'My G.o.d, that ties three things together, straight away. The need for sunlight, number one. The Cloud making a bee-line for the Sun, number two. The Cloud stopping when it reached the Sun, number three. Very good, Chris.'

'It is a very good beginning, yes, but it leaves some things obscure,' Yvette Hedelfort remarked. 'I do not see,' she went on, 'how it was that the Cloud came to be out in s.p.a.ce. If it has need of sunlight or starlight, surely it would stay always around one star. Do you suppose that this beast of yours has just been born somewhere out in s.p.a.ce and has now come to attach itself to our Sun?'

'And while you're about it, Chris, will you explain how your friend the beast controls its supplies of energy? How did it manage to fire off those blobs of gas with such fantastic speed when it was slowing down?' asked Leicester.

'One question at a time! I'll take Harry's first, because its probably easier. We tried to explain the expulsion of those blobs of gas in terms of magnetic fields, and the explanation simply didn't work. The trouble was that the required fields would be so intense that they'd simply burst the whole Cloud apart. Stated somewhat differently, we couldn't find any way in which large quant.i.ties of energy could be localized through a magnetic agency in comparatively small regions. But let's now look at the problem from this new point of view. Let's begin by asking what method we ourselves would use to produce intense local concentrations of energy.'

'Explosions!' gasped Barnett.

'That's right, explosions, either by nuclear fission, or more probably by nuclear fusion. There's no shortage of hydrogen in this Cloud.'

'Are you being serious, Chris?'

'Of course I'm being serious. If I'm right in supposing that some beast inhabits the Cloud, then why shouldn't he be at least as intelligent as we are?'

'There's the slight difficulty of radioactive products. Wouldn't these be extremely deleterious to living material?' asked McNeil.

'If they could get at the living material, certainly they would. But although it isn't possible to produce explosions with magnetic fields, it is possible to prevent two samples of material mixing with each other. I imagine that the beast orders the material of the Cloud magnetically, that by means of magnetic fields he can move samples of material wherever he wants inside the Cloud. I imagine that he takes very good care to keep the radioactive gas well separated from the living material remember I'm using the term "living" for verbal convenience. I'm not going to be drawn into a philosophical argument about it.'

'You know, Kingsley,' said Weichart, 'this is going far better than I thought it would. What I suppose you would say is that whereas basically we a.s.semble materials with our hands, or with the aid of machines that we have made with our hands, the beast a.s.sembles materials with the aid of magnetic energy.'

'That's the general idea. And I must add that the beast seems to me to have far the better of it. For one thing he's got vastly more energy to play with than we have.'

'My G.o.d, I should think so, billions of times more, at the very least,' said Marlowe. 'It's beginning to look, Chris, as if you're winning this argument. But we objectors over here in this corner are pinning our faith to Yvette's question. It seems to me a very good one. What can you offer in answer to it?'

'It is a very good question, Geoff, and I don't know that I can give a really convincing answer. The sort of idea I've got is that perhaps the beast can't stay for very long in the close proximity of a star. Perhaps he comes in periodically to some star or other, builds his molecules, which form his food supply as it were, and then pushes off again. Perhaps he does this time and time again.'

'But why shouldn't the beast be able to stay permanently near a star?'

'Well, an ordinary common or garden cloud, a beastless cloud, if it were permanently near a star, would gradually condense into a compact body, or into a number of compact bodies. Indeed, as we all know, our Earth probably condensed at one time from just such a cloud. Obviously our friend the beast would find it extremely embarra.s.sing to have his protective Cloud condense into a planet. So equally obviously he'll decide to push off before there's any danger of that happening. And when he pushes off he'll take his Cloud with him.'

'Have you any idea how long that will be?' asked Parkinson.

'None at all. I suggest that the beast will push off when he's finished recharging his food supply. That might be a matter of weeks, months, years, millennia for all I know.'

'Don't I detect a slight smell of rat in all this?' Barnett remarked.

'Possibly. I don't know how keen your sense of smell is, Bill. What's your trouble?'

'I've got lots of troubles. I should have thought that your remarks about condensing into a planet apply only to an inanimate cloud. If we grant that the Cloud is able to control the distribution of material within itself, then it could easily prevent condensation from taking place. After all, condensation must be a sort of instability process and I would have thought that quite a moderate degree of control on the part of your beast could prevent any condensation at all.'

'There are two replies to that. One is that I believe the beast will lose his control if he stays too long near the Sun. If he stays too long, the magnetic field of the Sun will penetrate into the Cloud. Then the rotation of the Cloud round the Sun will twist up the magnetic field to blazes. All control would then be lost.'

'My G.o.d, that's an excellent point.'

'It is, isn't it? And here's another one. However different our beast is to life here on Earth, one point he must have in common with us. We must both obey the simple biological rules of selection and development. By that I mean that we can't suppose that the Cloud started off by containing a fully-fledged beast. It must have started with small beginnings, just as life here on Earth started with small beginnings. So, to start with, there would be no intricate control over the distribution of material in the Cloud. Hence if the Cloud had originally been situated close to a star, it could not have prevented condensation into a planet or into a number of planets.'

'Then how do you visualize the early beginnings?'

'As something that happened far out in interstellar s.p.a.ce. To begin with, life in the Cloud must have depended on the general radiation field of the stars. Even that would give it more radiation for molecule-building purposes than life on the Earth gets. Then I imagine that as intelligence developed it would be discovered that food supplies i.e. molecule-building could be enormously increased by moving in close to a star for a comparatively brief period. As I see it, the beast must be essentially a denizen of interstellar s.p.a.ce. Now, Bill, have you any more troubles?'

'Well, yes, I've got another problem. Why can't the Cloud manufacture its own radiation? Why bother to come in close to a star? If it understands nuclear fusion to the point of producing gigantic explosions, why not use nuclear fusion for producing its supply of radiation?'

'To produce radiation in a controlled fashion requires a slow reactor, and of course that's just what a star is. The Sun is just a gigantic slow nuclear fusion reactor. To produce radiation on any real scale comparable with the Sun, the Cloud would have to make itself into a star. Then the beast would get roasted. It'd be much too hot inside.'

'Even then I doubt whether a cloud of this ma.s.s could produce very much radiation,' remarked Marlowe. 'Its ma.s.s is much too small. According to the ma.s.s-luminosity relation it'd be down as compared with the Sun by a fantastic amount. No, you're barking up a wrong tree there, Bill.'

'I've a question that I'd like to ask,' said Parkinson. 'Why do you always refer to your beast in the singular? Why shouldn't there be lots of little beasts in the Cloud?'

'I have a reason for that, but it'll take quite a while to explain.'

'Well, it looks as if we're not going to get much sleep tonight, so you'd better carry on.'

'Then let's start by supposing that the Cloud contains lots of little beasts instead of one big beast. I think you'll grant me that communication must have developed between the different individuals.'

'Certainly.'

'Then what form will the communication take?'

'You're supposed to be telling us, Chris.'

'My question was purely rhetorical. I suggest that communication would be impossible by our methods. We communicate acoustically.'

'You mean by talking. That's certainly your method all right, Chris,' said Ann Halsey.