The footsteps sounded near, slipping and sliding on the shards of stone that lay outside the cave mouth. A beam of light speared into the cave.

Thinker pulled himself tighter and denser and reduced his field. The field might betray him, he knew, but he could not reduce it much farther, even so, for it was a part of him and he could not exist without it. Especially not here, not at this moment, with the chill of the atmosphere sucking hungrily at his energy.

We must be ourselves, he thought. I, myself, and Quester quester's self and Changer changer's self. We cannot be more or less than we are and we cannot change except through the process of long, slow evolution, but in the millennia to come might it not be possible that the three would meld as one, that there would not be three separate minds, but one mind only? And that mind would have emotion, which I do not have, which I can recognize, but cannot understand, and the hard, cold, impersonal logic which is mine, but not my companions', and the keen sharp sensitivity which is Quester's, but is neither mine nor Changer's. Blind chance alone that put the three of us together, that put our minds inside a mass of matter which can be made a body — what were the odds that such a happening could have come about? Blind chance or destiny? What was destiny? Was there destiny? Could there be some great, overriding universal plan and was this happening which had put the three of them together one part of that plan, a necessary step before the plan could reach that remote conclusion towards which it always moved?

The human was crawling closer, the loose rock sliding underneath his feet, his hands clawing at the ground to hold himself against the downhill pull of gravity, the lighted flashlight in one fist bobbing and bouncing so that it threw an erratic arch of light.

He got one elbow over the lip of the cave and hoisted himself upward so that his head was level with the opening.

He gasped and yelled.

'Hey, Bob, this cave has a funny smell. There's been something in here. Just a while ago.

Thinker expanded his field, pushing it outwards violently. It hit the man like a plunging fist. It knocked his elbow loose from the lip of rock and hurled him outwards and away. He twisted and plunged downwards. He screamed once, a shriek of terror pushed out of his lungs. Then his body thumped and slid. Thinker could sense its sliding, taking with it rocks that bounced and clicked, trash wood that slithered and rattled. The slithering and the clicking stopped and from the slope below came the sound of splashing.

Thrashing bodies went plunging down the slope, lights bobbing back and forth, sweeping across brush and shiny tree trunks.

Voices cried out:

'Bob, something happened to Harry!

'Yeah, I heard him yell.

'He's down there in the creek. I heard him hit the water.

The plunging bodies kept on going past, going down the hill in braking rushes. Half a dozen lights bobbed madly at the bottom of the slope and several of the humans were wading in the stream. From farther off came other shouts.

Something stirred questioningly inside Thinker's mind.

— Yes, he asked, what is it?

— What do we do now? growled Quester. You heard what he yelled. They're all excited now, but one of them will remember. There'll be some of them coming up here. They may start shooting at us.

— I agree, said Changer. They'll investigate. The man who fell…

— Fell! said Thinker, witheringly. I pushed him.

— All right, then. The man you pushed tipped them off.

He smelled Quester, maybe.

— I don't stink, said Quester.

— That's ridiculous, said Thinker. I would suspect all three of us have distinctive body odours. Your body form was there long enough to contaminate the cave.

— It might have been your body odour, said Quester. Don't forget…

— Cut it out, said Changer, sharply. The question isn't which one of us he smelled. It is what do we do now. Thinker, can you change into something thin and flat, a shape that will give no profile, and creep out of here and up the hill?

— I doubt it. The planet's far too cold. I'm losing energy too fast. If I extended my body surface I'd lose it that much faster.

— That's a problem we have to face, said Quester. The problem of retaining sufficient energy. Changer will have to eat for us. He'll have to supply the energy, ingesting in his own body form the foods that are available. And staying in his body's form long enough for the food to be digested. There are few energy sources for Thinker and probably no food that I could eat and that my bodily apparatus would be able to handle. I would suspect…

— This all is true, said Changer. But let's consider it some other time. For the moment, let's go back to our present problem. Can you take over, Quester? They'd spot me. My body would show up white.

— Certainly I can, said Quester.

— Good. Crawl out of the cave and up the hill. Go easily, go quietly. But as swiftly as you can. We've got the searching party all together and if they don't hear you, it's unlikely we'll run into any of them.

— Over the hill, asked Quester, and then what?

— Up on one of the drives, said Changer, we should find a public telephone.

'If what you believe is true, Chandler Horton said, 'then we must lose no time in contacting Blake.

'What makes you think it's Blake any longer? asked the chief of staff. 'It wasn't Blake that ran off from this hospital. If Daniels is right, it was an alien creature.

'But Blake was there, too, protested Horton. 'It might have been in an alien's body, but it could change back to Blake.

Senator Stone, hunched up in the big chair, sneered at Horton. 'If you want to know what I think, he said, 'this all is poppycock.

'We are interested in your thoughts, of course, said Horton. 'But I do wish, Solomon, that for once your thinking could be a bit constructive.

'What is there to be constructive about? yelled Stone. 'This is some sort of childish, put-up job. I haven't got it figured out yet, but I know that is what it is. And I'll wager you're at the bottom of it, Chandler. You're always up to tricks. You've got this deal rigged up to prove something, more than likely, but so far I don't quite see what it is. I knew there was something going on when you got this Lukas joker to testify.

'Dr Lukas, if you don't mind, senator, said Horton.

'Well, all right then, Dr Lukas. What does he know about it?

'Let's find out, said Horton. 'Dr Lukas, what do you know about it?

Lukas grinned drily. 'As to what happened in this hospital, not a thing at all. As to whether it could happen as Dr Daniels believes it could — why, I must agree with him.

'But it's supposition, Stone pointed out. 'Nothing but supposition. Dr Daniels got it figured out. Fine! Good! Bully for him! He's got a good imagination. But it doesn't mean that what he thinks is actually what happened.

'I must point out to you, said the chief of staff, 'that Blake was Dr Daniels' patient.

'Which means you believe what he thinks?

'Not necessarily. I don't know what to think. But if anyone is entitled to any opinion, it is Daniels here.

'Now let's all calm down a bit, suggested Horton, 'and take a look at what we have. I scarcely think it's necessary to dignify the senator's charges that this is a put-up job with any sort of answer, but I think we must all agree that something most unusual did happen here tonight. I also doubt that the decision by Dr Winston to call us all together was one that was lightly made. He now says he can form no solid opinion, but certainly he must have felt there was some reason for concern.

'I still think there is, said the chief of staff.