Fantastic Voyage II: Destination Brain

Chapter 9. Artery

Morrison's eyes remained, for the most part, focused on the recess before him, on the computer, and on the software he had inserted. The software - the one material object of the long ago.

Long ago? It was less than a hundred hours ago that he was half-dozing his way through a dull talk on his last day at the conference and wondering whether there was any way to save his position at the university. And now a hundred subjective years had passed in those hundred objective hours and he could no longer clearly visualize the university at all or the life of sad frustration he had been leading there toward the end.

He would have given a great deal to have broken out of the dull cycle of useless striving a hundred hours ago. He would give a great deal more - a great deal more - to break back into it now, to wake up and to find the last hundred hours (or years) had never taken place.

He glanced through the transparent wall of the ship, there at his right elbow, his eyes half-closed as though he were really reluctant to see anything. He was reluctant. He did not want to see anything larger than it should be. It would interfere with his wild hope that the miniaturization process had broken down or that the whole thing had - somehow - been an illusion.

But a man walked into his view - tall, over two meters tall. But then, perhaps he was actually that tall.

Others appeared. They couldn't all be that tall.

He shrank down into his seat and looked no more. It was enough. He knew that the miniaturization process was going its inexorable way.

The silence inside the ship was oppressive, unbearable. Morrison felt he had to hear a voice, even if only his own.

Kaliinin, at his left side, was the one to whom he could speak most easily and she might be the best of a difficult choice, perhaps. Since Morrison did not want Dezhnev's misplaced jocularity, or Boranova's one-dimensional concentration, or Konev's dark intensity, he turned to Kaliinin's frozen sorrow.

He said, "How will we get into Shapirov's body, Sophia?"

It took a while, it seemed, for Kaliinin to hear him. When she did, her lips moved pallidly and she said in a whisper, "Injection."

Then, as though with a supreme effort, she apparently decided that she must be companionable, so she turned to him and said, "When we are small enough, we will be placed into a hypodermic needle and injected into Academician Shapirov's left carotid artery."

"We'll be shaken up like dice," said Morrison, appalled.

"Not at all. It will be complex, but the problems have been thought through."

"How do you know? This has never been done before. Never in a ship. Never in a hypodermic needle, Never into a human body."

"True," said Kaliinin, "but problems like this - much simpler ones, of course - have been planned for a long time and we have had extended seminars over the last few days on this mission. You don't think that Arkady's announcements before miniaturization began - the ones about toilet tissue and so on - were new to us, do you? We have heard it all before, over and over. It was for your benefit, actually, since you have attended no seminars, and for Arkady's, too, since he loves his moment in the sun."

"Tell me, then, what will happen?"

"I will explain events as they occur. For now we do nothing until we are in the centimeter range. It will take another twenty minutes, but not everything will be so slow. The smaller we get, the faster we can miniaturize, in proportion. - Have you felt any bad effects yet?"

Morrison mentally subtracted the rapid beating of his heart and the panting of his lungs and said, "None." Then, feeling that to be an unduly optimistic remark, he added, "At least so far."

"Well, then?" said Kaliinin and closed her eyes as though to indicate that she was tired of talking.

Morrison thought that might not be such a bad idea and closed his as well.

He might have actually fallen asleep or he might simply have gone into a protective state of semi unconsciousness, withdrawing from reality, for it seemed that no time had passed when he was brought to by a slight jar.

He opened his eyes wide and found himself a centimeter or so above the seat. He had the odd sensation of drifting with each vagrant puff of wind.

Boranova had moved over to the seat behind him and placed her hands on his shoulders. She pushed down gently and said, "Albert, put on your seat belt. Sophia, show him how. I'm sorry, Albert - we should have gone over all of this - everything - before we started, but we had little time and you were nervous enough as it was. We did not wish to reduce you to utter helplessness by flooding you with information."

To his own surprise, Morrison had not been feeling helpless. He had rather enjoyed the sensation of sitting on air.

Kaliinin touched a spot on her seat edge between her knees and a belt around her waist flipped away. It had not been there, Morrison was sure, when he had closed his eyes and now it was again no longer there, for it disappeared, with a snap, into a recess in the seat to her left. She twisted toward Morrison and said, "This, here to your left, is your belt ejector." Morrison couldn't help noticing that, now unbound, she lifted up from her seat slightly as she moved toward him.

She pressed the ejector - a somewhat darker circle in a light background - and a flexible network of clear plastic shot out with a faint hiss, wrapped itself about him, and buried its triple tip into the seat at his other side. He found himself held, elastically, in a kind of lacework.

"If you want to free yourself, there is the belt release there, just between your knees." Kaliinin leaned farther toward him to indicate the place and Morrison found the pressure of her body against his to be pleasurable.

She did not seem to be aware of it and, having completed her task, she pulled herself back into her chair and re-belted herself.

Morrison glanced quicky around, squeezing upward and forward as far as the belt would let him, and peered, with difficulty, over Konev's shoulder. All five were belted.

He said, "We've miniaturized to the point where we have very little weight, is that it?"

"You only weigh about twenty-five milligrams now," said Boranova, "so that you might as well consider yourself weightless. Then, too, the ship is being lifted."

Morrison looked at Kaliinin accusingly and Kaliinin shrugged slightly and said, "I told you I'd describe things as they happened, but you seemed to be asleep and I thought it wiser to let you stay that way. The jar of the clamp woke you and lifted you out of the seat."

"The clamp?" He looked to one side. He had been conscious of a shadow on both sides, but walls were supposed to be opaque and he had dismissed the sensation. Now he suddenly remembered that the ship's walls were transparent and realized that the light on either side was blocked.

Kaliinin nodded. "A clamp is gripping us and helping to keep us steady so that we are not shaken up unnecessarily. It looks enormous, but it is a very small and delicately padded clamp. And we are being put into a small tank of saline solution. We are also being held steady by an airstream being sucked upward into a blunt nozzle. That pushes us against the nozzle so that, with the clamps, we are held three ways."

Morrison looked out again. Objects outside the ship that might have been visible through portions of the wall not blocked by the clamp or by the overhead nozzle were, nevertheless, not visible. Morrison could see occasional shifting of light and shadow and realized that whatever existed out there was too large to make out clearly with his tiny eyes. If the photons that approached the ship were not themselves miniaturized as they entered the field, they would behave as though they were long radio waves and he would have seen nothing at all.

He felt the ship suddenly jar again as the clamps withdrew, although he couldn't actually see them withdraw. One moment they were there and the next they weren't. The movement - on his scale - was too rapid to see.

Then he felt himself rising slightly against the belt that bound him in and he interpreted that as a downward movement of the ship. There followed a slow bobbing sensation.

Dezhnev pointed to a dark horizontal line that moved slowly up and down against the wall of the ship and said with satisfaction, "That's the surface of the water. I thought the motions would be worse. Apparently, there are engineers in this place who are almost as good as I am."

Boranova said, "Actually, engineering has little to do with it. We're being held in place by surface tension. That will only work while we're at the surface of a fluid. It will not affect us once we're in Shapirov's body."

"But this ripple effect, Natasha? This up-and-down movement. Is that affecting it at all?"

Boranova was studying her instruments and, in particular, a small screen on which a horizontal line seemed to be playing out forever, without budging from the center. Morrison, twisting and lifting until his back ached, could just make it out.

Boranova said, "It's as steady as your hand when you are sober, Arkady."

"No better than that, eh?" Dezhnev's laugh boomed out.

(He sounds relieved, thought Morrison uneasily and wondered what the "it" was that Dezhnev had felt might be affected.)

"What happens now?" asked Morrison.

Konev spoke for the first time, as far as Morrison could remember, since miniaturization had begun. "Must everything be explained to you?"

Morrison answered with spirit. "Yes! You have had everything explained to you. Why should I not have it explained as well?"

Boranova said quietly, "Albert is perfectly correct, Yuri. Please hold your temper and be reasonable. You will need his help soon enough and I hope he will not be so discourteous as to snap at you."

Konev's shoulders twitched, but he said nothing in reply.

Boranova said, "The cylinder of a hypodermic syringe will pick us up, Albert. It will be under remote control."

And, as though that cylinder were waiting to hear her say so, a shadow encased them from behind, swallowing them almost at once. Only in front was there a circle of light visible for a moment and then that disappeared, too.

Boranova said calmly, "The needle has been clamped on. Now we will have to wait a while."

The interior of the ship, which had become quite dark, was suddenly suffused with a white light, rather softer and more restful than before, and Boranova said, "From now on there will be no more light from the outside until our journey is over. We will have to rely on our own internal illumination, Albert."

Puzzled, Morrison looked around for the source of the light. It seemed to be in the transparent walls themselves.

Kaliinin, interpreting his glance, said, "Electroluminescence."

"But what is the source of power?"

"We have three microfusion engines." She looked at him proudly. "Of a type that's the best in the world." Then she repeated, "In the world."

Morrison let it go. He had the impulse to talk of the American microfusion engines on the latest space vessels, but what would be the point? Someday the world would be freed of its nationalist fervors, but that day had not yet arrived. Still, as long as those fervors did not express themselves in violence or threat of violence, matters were bearable.

Dezhnev, leaning back in his seat with his arms behind his neck and apparently addressing the gently illuminated wall before him, said, "Someday what we will do is expand a hypodermic syringe, place that around a full-sized ship, and miniaturize the whole thing. Then we won't have this small-scale maneuvering."

Morrison said, "Oh, can you do the other thing, too? What do you call it? Maximization? Gigantization?"

"We don't call it anything," said Konev crisply, "because it can't be done."

"Maybe someday, though."

"No," said Konev. "Never. It is physically impossible. It takes a lot of energy to miniaturize, but more than an infinite amount to maximize."

"Even if you hooked it up to relativity?"

"Even so."

Dezhnev made an inelegant sound with his lips. "That for your physically impossible. Someday you will see."

Konev relapsed into indignant silence.

Morrison said, "What is it we are waiting for?"

Boranova said, "The last-minute preparation of Shapirov and then the moving up of the needle and its insertion into the carotid."

As she spoke, the ship was jarred forward.

"Is that it?" asked Morrison.

"Not yet. They were merely removing the air bubbles. Don't worry, Albert. We'll know."

"How?"

"Why, they'll tell us. Arkady is in contact with them. It's not difficult. Radio wave photons miniaturize as they cross the boundary from there to here and deminiaturize as they cross in the other direction. There's very little energy involved - even less than in the case of light."

Dezhnev said, "It's time to move up to the base of the needle."

"Then go ahead," said Boranova. "We might as well test the motive power under miniaturization."

There was a gathering rumble that reached a low peak and then settled down into a buzzing murmur. Morrison twisted his head in order to look as nearly backward as he could against his restraining belt.

Water was churning behind them as though paddle wheels were turning. In the absence of any real reference point outside, it was impossible to judge how quickly they were moving, but progress seemed slow to Morrison.

"Are we moving much?" he asked.

"No, but we don't need to," said Boranova. "There's no use wasting energy trying to move faster. After all, we're pushing against normal-sized molecules, which means high viscosity on our scale."

"But with microfusion motors -"

"We have many energy needs for matters other than propulsion."

"I'm just wondering how long it will take us to get to key points in the brain."

"Believe me," said Boranova grimly, "I'm wondering, too, but we will have an arterial current taking us as close as possible."

Dezhnev cried out, "We're there! See?"

Right ahead, in the forward light beam of the ship, a round circle could be seen. Morrison had no trouble translating that into the base of the needle.

On the other end of that needle, they would find Pyotr Shapirov's bloodstream and then they would actually be within a human body.

Morrison said, "We're too large to go through the needle, Natalya."

He felt a peculiar amalgam of emotions at the thought. Uppermost was a feeling of hope that perhaps the whole experiment had failed. This might be as small as they could get and it wasn't small enough. They would have to deminiaturize and it would all be over.

Under that thought, well-hidden, was a little sigh of disappointment. Having come so far, might it not be as well to get into the body and experience the interior of a nerve cell? Ordinarily, being no darer of dangers, no scaler of heights, Morrison would have turned away in horror at the thought - he did turn away in horror - but having miniaturized, having reached this point, having survived the fright so far, was it possible that he might want to go farther?

But above these contradictory urges came a bit of realism. Surely these people were not such fools as to deal with a ship that could not be reduced to a size that would pass through the needle it was supposed to pass through. No conceivable stupidity in these very intelligent people could reach that pitch.

And Boranova, as though she were resonating with that thought, said, almost indifferently, "Yes, we are too large now, but we will not stay too large. That is my job here."

"Yours?" said Morrison blankly.

"Of course. We have been reduced to this point by our central miniaturization device. Now the fine adjustments will be made by me."

Kaliinin murmured, "That is one of the things we must save our microfusion motors for as much as possible."

Morrison looked from one to another. "Do we have enough energy on board ship for further miniaturization? Surely the impression I got was that a vast quantity of energy was needed for -"

"Albert," said Boranova, "if gravitation were quantized, then it would take the same enormous amount of energy to reduce a mass by half, regardless of the original value of that mass. To reduce the mass of a mouse by half would take the same energy as was required to reduce the mass of an elephant by half. But the gravitational interaction is not quantized and, therefore, neither is mass loss. That means that the energy required for mass loss decreases with that loss - not entirely in proportion, but to an extent. We have so little mass now that it takes much less energy to miniaturize further."

Morrison said, "But since you've never miniaturized anything as large as this ship through so many orders of magnitude, you are depending on the extrapolation of data obtained for a much different size range."

(They're not speaking to an infant, he thought indignantly. I am their equal.)

"Yes," said Boranova. "We are taking the chance that the extrapolation will hold, that something new and unexpected will not surprise us. Still, we live in a Universe that faces us with uncertainties now and then. That can't be helped."

"But we all face death if something goes wrong."

"Didn't you know that?" said Boranova calmly. "Have you been uneasy about this fantastic voyage of ours simply for the pleasure of being uneasy? But we are not alone in this. If things go wrong and the stored energy of miniaturization is released, it will not only destroy us, but it may damage the Grotto to some extent. I'm sure that many an unminiaturized person out there is holding his or her breath and wondering if he or she will survive an explosion. You see, Albert, even those who are not undergoing the risks of miniaturization are not altogether safe."

Dezhnev turned and grinned widely. Morrison noted that one of his upper molars was capped and did not match the rather yellowish tint of his other teeth.

Dezhnev said, "Concentrate on the thought, my friend, that if something goes wrong, you will never know. My father used to say, 'Since we all must die, what better can we ask for than a quick and sudden death?'"

Morrison said, "Julius Caesar said the same thing."

Dezhnev said, "Yes, but we won't even have time to say, 'Et tu, Brute.'"

"There will be no death," said Konev sharply, "and it is foolish to speak of it. The equations are correct."

"Ah," said Dezhnev. "There was a time of superstition when people relied on the protection of God. Thank Equations we now have Equations to rely on."

"Not funny," said Konev.

"I didn't mean to be funny, Yuri. - Natasha, they're ready out there for us to proceed."

Boranova said, "Then there will be no further need to speculate. Here we go."

Morrison gripped his seat tightly, preparing himself, but he felt nothing happen. Up front, though, the round circle he had made out expanded and grew dimmer and dimmer as it moved very slowly backward until it could no longer be made out.

"Are we moving?" he asked automatically. It was the kind of question one was unable to refrain from asking, even though the answer was obvious.

"Yes," said Kaliinin, "and we are expending no energy in doing so. We are not battling the water molecules. We are being carried along by the water flow in the needle as the cylinder presses in slowly."

Morrison was counting to himself. It kept his mind more efficiently occupied than studying the second hand of his watch would have done.

When he reached a hundred, he said, "How long will it take?"

"How long will what take?" asked Kaliinin.

"When do we reach the bloodstream?"

Dezhnev said, "A few minutes. They are going very slowly, just in case there is some kind of microturbulence. As my father once said, 'It is slower, but better, to creep along the downward path than to leap over the cliff.'"

Morrison grunted, then said, "Are we still miniaturizing?"

Boranova answered from behind him. "No. We are down in the cellular range and that is far enough for our needs now."

Morrison was surprised to find that he was trembling. After all, so much was happening and so many new things existed to think about that he had somehow lacked the room to remain in terror. He was not terrified, at least not to an acute stage - yet for some reason he continued to tremble.

He attempted to will himself to relax. He tried to let himself droop, but that required more than an effort of will. It needed gravitational pull and there was none to speak of. He closed his eyes and slowed his breathing. He even tried humming, under his breath, the choral singing from Beethoven's Ninth Symphony.

Finally he felt himself forced into comment on the matter. "I'm sorry," he said. "I seem to be shaking."

Dezhnev snickered. "Aha! I wondered who would be the first to mention it."

Boranova said, "It's not you, Albert. We are all shaking slightly. It's the ship."

Morrison was at once elevated into fright. "Is something wrong with it?"

"No. It's just a matter of size. It's small enough to feel the effect of Brownian motion. You know what that is, don't you?"

It was a purely rhetorical question. Boranova would surely expect a high school student of physics to know what Brownian motion was, let alone Morrison, and yet Morrison found himself explaining it in his own mind - not in words, but as a flash of concept.

Every object suspended in a liquid is bombarded on all sides by the atoms or molecules of the liquid. These particles strike randomly and therefore unevenly, but the unevenness is so small compared to the total that it is unnoticeable and has no measurable effect. As an object grows smaller, however, the unevenness becomes greater among the smaller and smaller number of particles striking the object in a given time. The ship was small enough now to respond to the slight excesses of coillisions - first in one direction, then in another - randomly. It moved slightly in consequence, a random trembling.

Morrison said, "Yes, I should have thought of that. It will get worse if we continue to become smaller."

"Actually, it won't," said Boranova. "There will be other counteracting effects."

"I don't know of any," said Morrison, frowning.

"Nevertheless, there will be such effects."

"Leave it to the Equations," said Dezhnev in an affectedly pious tone. "The Equations know."

Morrison said, "I think this could make us seasick."

"It certainly would," said Boranova, "but there is a chemical treatment for that. We have been dosed with the same chemical that cosmonauts use against space sickness."

"Not I," said Morrison indignantly. "Not only haven't I been treated, I haven't even been forewarned."

"We told you as little as possible of the discomforts and dangers out of concern for your comfort, Albert. As for treatment, you consumed your dose with your breakfast. - How do you feel?"

Morrison, who had begun to feel a bit squeamish with all this talk about sickness, decided that he felt fine. Astonishing, he thought, the tyranny exerted over the body by the mind.

He said in a low voice, "Tolerable."

"Good," said Boranova, "because we are now in Academician Shapirov's bloodstream."

Morrison stared through the transparent wall of the ship.

Blood?

His first impulse was to expect redness. What else?

He peered out, squinting his eyes slightly, but could see nothing, even in the gleaming light of the ship. He might as well have been in a rowboat, drifting down the calm surface of a pond on a dark and cloudy night.

Morrison's thoughts suddenly veered. In the absolute sense, the light within the ship had the wavelength of gamma rays - and very hard gamma rays at that. Yet the wavelengths were the result of miniaturizing ordinary visible light and to the equally miniaturized retinas and optic lobes of the people within the ship they were still light rays and had the property of light rays.

Outside, just beyond the hull of the ship, where the miniaturization field ended, the miniaturized photons enlarged to ordinary light-wave photons and those that were reflected back to the ship were miniaturized again when the field boundary was crossed. The others might be accustomed to this paradox-ridden situation, but to Morrison the attempt to grasp the effect of a miniaturized bubble within a sea of normality was dizzying. Was the boundary visible, marking off the miniaturized from the normal? Was there a discontinuity somewhere?

Following his line of thought, he whispered to Kaliinin, who was bent over her instrument, "Sophia, when our light leaves the miniaturization field and expands, it must give off heat energy, and when it's reflected back into the ship it must absorb energy in order to be miniaturized and the energy must come from us. Am I right?"

"Perfectly, Albert," said Kaliinin without looking up. "Our use of light results in a small but steady loss of energy, but our motors can supply that. It is not a significant drain."

"And are we really in the bloodstream?"

"Never fear. We are. Natalya will probably dim the internal lights in a while and you'll see the outside more clearly then."

Almost as though that were a signal, Boranova said, "There! Now we can relax for a few moments." The lights dimmed.

At once, objects outside the ship came dimly into view. He could not make them out clearly yet, but they were immersed in something heterogeneous, something with objects floating in it, as would be true of blood.

Morrison stirred uneasily, straining at the constraint of his seat belt. He said, "But if we are in the bloodstream, which is at a temperature of thirty-seven degrees Celsius, we'll -"

"Our temperature is conditioned. We'll be quite comfortable," said Kaliinin. "Really, Albert, we've thought of these things."

"Perhaps you have," said Morrison, slightly offended, "but I haven't been privy to those thoughts, have I? How can you condition the temperature when you don't have a cold sink?"

"We don't have one here, but there's outer space, isn't there? The microfusion motors give off a thin drizzle of subatomic particles which, under miniaturized conditions, have a mass of very nearly zero. They therefore travel at virtually the speed of light, penetrating matter as easily as neutrinos do and carrying off energy with them. In less than a second they are in outer space, so that the effect is of transferring heat from within the ship into outer space and we keep cool. Do you see?"

"I see," muttered Morrison. It was ingenious - but perhaps obvious, after all, to those used to thinking in terms of miniaturization.

Morrison noticed that the controls of the ship, immediately under Dezhnev's hands, were luminous, as were the instruments before Kaliinin. He struggled to raise himself in his seat and managed to see a corner of the computer screen in front of Konev. It contained what Morrison thought might be a map of the circulatory system of the neck. For a moment, before his body ceased its fight against the webbing of the belt and he sank down into his seat again, he saw a small red dot on the screen, which, he deduced, was a device to mark the position of the ship in the left internal carotid artery.

He was panting a little from his effort and had to wait a few moments to regain control of his breath. The recess in which his own computer rested was illuminated and he shielded that bit of light from his face by raising his left hand. Then he looked out.

Far in the distance, Morrison could see something that looked like a wall, a barrier of some sort. It receded, then approached, then receded again, over and over, rhythmically. Automatically, he looked at his watch for a few seconds. It was clearly the pulsation of the arterial wall.

He said to Kaliinin in a low voice, "Obviously the passage of time is not affected by miniaturization. At least the pulsation of the heart is - just what it ought to be, even though I view it with miniaturized eyes and time it with a miniaturized watch."

It was Konev who answered. "Time isn't quantized apparently, or at least it isn't affected oy the miniaturization field, which may be the same thing. That's convenient. If we had to take a shifting time flow into account, things might become unbearably complicated."

Morrison silently agreed and turned his thoughts in other directions.

If they were inside an artery, and if the ship were merely being swept forward by the current, the forward movement would have to be in spurts, one spurt for each contraction of the distant heart (the very distant heart - on the scale of their present size). And if that were so, he ought to feel those spurts of motion.

He closed his eyes and tried to hold as still as possible, to move not at all except for the trembling of the Brownian motion - which, after all, he could in no way control.

Ah, he could feel it. A slight but distinct push backward as the spurt started, a slight push forward as it came to an end.

But why was the spurt not more energetic? Why was he not yanked backward and forward in a sickening fashion?

And then he thought of the mass he no longer possessed. With his remaining mass so tiny, his inertia was similarly tiny. The viscosity of the normal fluid of the bloodstream exerted an enormous cushioning effect, so that the spurts were all but lost in the Brownian motion.

And, ever so slightly, Morrison felt himself relax. He felt something inside himself untighten a bit. The miniaturized environment was unexpectedly benign.

He looked through the ship's transparent hull again, his eyes focusing on the volume between himself and the arterial wall. He could see bubbles, faintly outlined. No, not bubbles, but things of substance - many of them. Some turned slowly and changed apparent shape as they did so, so they were not spheres. They were disks, he now realized.

The truth burst in on him and shamed him. Why was he so slow in identifying them, since he knew he was in a bloodstream? - But then he knew the answer to that, too. He could not really conceive of himself as being in a bloodstream; it was too easy to suppose he was in a submarine making its way through an ocean. He would naturally expect to see the familiar sights of an ocean and would be foolishly puzzled at anything he saw that did not fit his assumption.

He would see the red corpuscles of the blood - the erythrocytes - and fail to recognize them.

Of course, they weren't red but faintly yellowish. Each one absorbed some shortwave light to produce that color. Get them in bulk, though, millions and billions of them, and they would absorb enough such light to appear red - in arterial blood, anyway, and they were in an artery now. Once the cells withdrew the oxygen carried by the red corpuscles, the individual corpuscle would seem faintly bluish, and, in bulk, blue-purple.

He watched the erythrocytes with interest and saw them quite clearly now that he had recognized them for what they were.

They were biconcave discs, the centers depressed on each side. To Morrison, they were enormous, considering that, under normal conditions, they were microscopic, perhaps seven and a half micrometers in diameter and a little over two micrometers thick. Now here they were, swollen objects the size of his hand.

There were many of them in sight and they had a tendency to pile together in roulettes. These weren't static, however. Some corpuscles would peel off the roulettes and others would add on and there were always some single corpuscles in view. Those that were in sight tended to stay in sight; they weren't moving relative to the ship.

"I take it," said Morrison, "that we're simply going with the flow."

"That's right," said Kaliinin. "It saves energy."

But, at that, the red corpuscles weren't entirely stationary relative to the ship. Morrison noticed one corpuscle drifting slowly toward the ship, carried perhaps by a bit of microturbulence or by a random push of Brownian motion. The corpuscle flattened slightly and momentarily against the plastic of the ship and then rebounded.

Morrison turned to Kaliinin. "Did you see that, Sophia?"

"The red corpuscle nudging us? Yes."

"Why didn't it miniaturize? Surely it entered the field."

"Not quite, Albert. It bounced off the field, which extends a small distance beyond any miniaturized object, such as our ship, in every direction. There's a certain repulsion between normal matter and miniaturized matter, and the greater the extent of miniaturization, the stronger the repulsion. That's why very tiny objects such as miniaturized atoms or subatomic particles go through matter without interacting with it. It's also that which keeps the miniaturized state metastable."

"How do you mean?"

"Any miniaturized object is always surrounded by normal matter, unless it is in deep space. If nothing served to keep normal matter out of the field, such matter would forever be miniaturizing and, in the process, absorbing energy from the miniaturized object. The drain would be significant and the miniaturized object would quickly deminiaturize. In fact, it would be impossible to induce miniaturization in the first place, since the energy crammed into the miniaturizing object would leak away at once. What we would then be trying to do, in effect, would be to miniaturize the entire Universe. - Of course, the repulsion isn't extremely strong at our size. If a red corpuscle collided with sufficient force, the colliding surface might undergo some miniaturization."

Morrison turned back to the view and, almost at once, something that was obviously a shredded red corpuscle drifted into view.

"Ah," said Morrison, "is that an example of one that approached us too forcefully?"

Kaliinin bent toward Morrison to get a better view in the direction he was pointing. She shook her head. "I don't think so, Albert. Red corpuscles have a limited life of about a hundred and twenty days. The poor things wear out and break down. In the volume of blood we can see, several dozen would break down every minute, so that torn and damaged red corpuscles would be a common sight. - And that is a good thing, too, for it means that if we were to use our power and rush through the bloodstream, breaking up a few red corpuscles, or even a few million, it would make no difference to Shapirov. We couldn't possibly break down red corpuscles at a rate even approaching that of natural breakdown."

Morrison said, "What about platelets?"

"Why do you ask?"

"That must be a platelet I see there." He pointed. "It's lentil-shaped and only half the size of the red corpuscles."

A pause and then Kaliinin nodded. "Ah yes, I see it now. That's a platelet. There should be one of them to every twenty red corpuscles."

That was about right, Morrison thought. If he were on a carousel, reaching out for rings as he passed, and reach red corpuscle were an ordinary iron ring, the occasional platelet would represent the coveted brass ring.

Morrison said, "My point, Sophia, is that platelets are more fragile than red corpuscles and when they break they start the clotting process. If we break a few, we'll start a clot forming in the artery. Shapirov will then have another stroke and surely die."

Boranova, who had been listening to the exchange between Morrison and Kaliinin, interposed at this point. "In the first place," she said, "platelets are not as fragile as all that. They can strike us lightly and rebound without harm. The danger of another stroke lies at the arterial wall. The platelets are moving much faster relative to the inner wall of the carotid artery than they are relative to us. And the inner wall of the artery may be layered with cholesterol and lipid plaques of all kinds. That surface is therefore much rougher and uneven than the smooth plastic hull of our ship. It's at the arterial wall that the clots might form - not here. And even that isn't too enormous a danger. A single platelet - or even a few hundred of them - might be broken and still be insufficient to start the clotting process in a way that doesn't damp out. Massive quantities of platelets must break to turn the trick."

Morrison watched a platelet that vanished, now and then, behind the numerous red corpuscles. He wanted to see if it would make contact with the ship and, if it did, what would happen. The platelet, however, did not oblige but remained at a distance.

It then occurred to Morrison that the platelet appeared to be as large as his hand. How could that be if they were half the diameter of the red corpuscles and the red corpuscles were themselves as large as his hand? His eyes sought out a red call and, sure enough, it seemed considerably larger than his hand.

He said, troubled, "The objects out there are getting larger."

"We're still miniaturizing, obviously," called out Konev, apparently annoyed at Morrison's seeming inability to draw the proper conclusion from an observed fact.

Boranova said, "That's right, Albert. The coronary is narrowing as we progress and we want to keep pace with it."

"We don't want to get stuck in the pipe," said Dezhnev genially, "by being too fat." Then, as another thought struck him, he added, "You know, Natasha, I've never been this thin in my life."

Boranova said, unmoved, "You are as fat as ever, Arkady, on the scale of Planck's constant."

Morrison was in no mood for airy banter. "But how far do we miniaturize, Natalya?"

"Down to molecular size, Albert."

And all of Morrison's apprehensions surged up again.

Morrison felt foolish at his failure to realize at once that they were still miniaturizing and, at the same time, bitterly resentful at Konev for making it plain he recognized that folly. The trouble was that all these others had been living and thinking miniaturization for years and he himself, a newcomer to the concept, was still trying to cram it into his reluctant brain. Couldn't they sympathize with his difficulties?

He studied the red corpuscles moodily. They were distinctly larger. They were wider across than his chest and their boundaries were becoming less sharp. Their surfaces quivered, as though they were canvas bags full of syrup.

He said in a low voice to Kaliinin, "Molecular size?"

Kaliinin looked quickly at him, then turned away and said, "Yes."

Morrison said, "I don't know why that should bother me, considering the small size to which we have already miniaturized, but there's something rather frightening about being as small as a molecule. How small a molecule, do you suppose?"

Kaliinin shrugged. "I don't know. That's up to Natalya. A virus molecule, perhaps."

"But this sort of thing has never been tried."

Kaliinin shook her head. "We're charting unknown territory."

There was a pause and then Morrison said uneasily, "Aren't you afraid?"

She looked at him furiously, but continued to whisper. "Of course I'm afraid. What do you think I am? It isn't sensible not to be afraid when you have rational reason for it. I was afraid when I was violated. I was afraid when I was pregnant and deserted. I've spent half my life being afraid. Everyone does. That's why people drink as much as they do, to wipe out the fear that grips them." She was virtually hissing through clenched teeth. "Do you want me to be sorry for you because you're afraid?"

"No," muttered Morrison, taken aback.

"There's nothing remarkable about being afraid," she went on, "as long as you don't act afraid - as long as you don't let yourself be twisted into doing nothing because of fear, into having hysterics because of fear, into failing -" She interrupted herself in a bitter, whispered self-accusation. "I've had hysterics in my time." Her glance flickered in the direction of Konev, whose back was straight, stiff, and motionless.

"But now," she went on, "I intend to do my part, even if I am half-dead with fear. No one will tell from my actions that I'm afraid. And that had better be your case, too, Mr. American."

Morrison swallowed hard and he said, "Yes, of course," but it sounded very unconvincing, even to him.

His eyes flicked backward, then forward. There was no use whispering in those close quarters. There was no whisper so low it would not be overheard.

Boranova, behind Kaliinin, was obviously busy with her miniaturization mechanism, but there was a tiny smile on her face. Approval? Contempt? Morrison couldn't tell.

As for Dezhnev, he turned his head and called out, "Natasha, it is continuing to narrow. Should you hasten the miniaturization?"

"I'll do what is needed, Arkady."

Dezhnev's eye caught Morrison's and he winked, with a grin. "Don't believe little Sophia," he said, pretending to whisper. "She is not afraid. Never afraid. She just doesn't want you to be alone with your uneasiness. She has a very soft heart, our Sophia, as soft as her -"

"Keep quiet, Arkady," said Sophia. "Surely your father must have told you that it is not wise to beat the empty teapot you call your head with the rusty spoon you call your tongue."

"Ah," said Dezhnev, rolling his eyes, "that was harsh. What my father did say was that no knife could be honed as sharp as a woman's tongue. - But, Albert, seriously, reaching molecular size is nothing. Wait until we have learned to attach relativity to quantum theory and then, with a tiny puff of energy, we will reduce ourselves to subatomic size. Then you will see."

"What will I see?" said Morrison.

"You would see instant acceleration. We would simply take off -" He removed his hands from the controls momentarily in order to make a whizzing gesture with them, accompanied by a shrill whistle.

Boranova said calmly, "Hands on the controls, Arkady."

"Of course, my dear Natasha," said Dezhnev, "A moment of excusable drama, no more." Then to Morrison, "Instantly we would go at nearly the speed of light, the much faster speed of light under such conditions. In ten minutes we could be across the Galaxy, in three hours at the Andromeda, in two years at the nearest quasar. And if that's not fast enough, we can get smaller still. We have faster-than-light travel, we have antigravity, we have everything. The Soviet Union will lead the way to it all."

Morrison said, "And how would you guide the flight, Arkady?"

"What?"

"How would you guide it?" said Morrison seriously. "As soon as the ship swoops down to the proper sizelessness and masslessness, it will, in effect, radiate outward at hundreds of light-years per second. That means that if there were trillions of ships, they would shoot out in every direction with spherical symmetry - like sunlight. But since there would only be one ship, it would move outward in one particular direction, but in an absolutely unpredictable one."

"That's a problem for the clever theoreticians - like Yuri."

Konev had not indicated any interest in the conversation up to that point, but now he snorted loudly.

Morrison said, "I'm not sure that it's wise to develop the traveling and carelessly assume the steering. Wouldn't your father say: 'A wise man does not build the roof of a house first.'"

"He might," said Arkady, "but what he once did say was this: 'If you find a gold key without a lock, don't throw it away. The gold is also sufficient.'"

Boranova stirred in her seat behind Morrison and said, "Enough with the saws and sayings, my friends. - Where are we, Yuri? Are we making progress?"

Konev said, "In my opinion we are, but I would like the American to support my judgment, or correct it."

"How can I do either?" snapped Morrison. "I'm strapped in."

"Then unstrap," said Konev. "if you float a bit, at least you can't float very far."

For a moment, Morrison fumbled at his seat belt, having forgotten the location of the appropriate contact. Kaliinin's hand moved quickly and he was free.

"Thank you, Sophia," he said.

"You will learn," she replied indifferently.

"Lift yourself so that you can see over my shoulder," said Konev.

Morrison did so and, inevitably, pushed too hard against the back of the seat ahead. As a result of his insignificant inertia, he moved upward explosively and struck his head against the roof of the ship. Had this happened at the same speed under unminiaturized conditions, he might well have suffered the blinding pain of a concussion, but the very lack of mass and inertia that had sent him shooting upward had bounced him back almost once with no sensation of pain and virtually none of pressure. He was as easy to stop as he had been to start.

Konev clicked his tongue. "Gently. Just lift your hand upward edgewise, turn it slowly, then push it down flatwise, slowly. Do you get it?"

Morrison said, "I understand."

He followed Konev's suggestion and moved up slowly. He caught at Konev's shoulder and stopped himself.

Konev said, "Now, look here at the cerebrograph. Do you see where we are at this moment?"

Morrison found himself looking at an enormously complex network, with a distinct three-dimensional effect. It consisted of sinuous rills branching outward in such a way as to form an exceedingly intricate tree. In one of the larger branches there was a small red dot, moving slowly and progressively.

Morrison said, "Can you give me a broader view so that I can place this section?"

Konev, with another click of his tongue, one that might have signified impatience, expanded the view. "Does this help?"

"Yes, we're on the edge of the brain." He could recognize the individual convolutions and fissures. "Where do you plan to go?"

The picture magnified somewhat. Konev said, "We'll curve off here into the interior of the neuronic layer - the gray matter. And where I'd like to head for, by this route" - he named the areas in Russian rapidly and Morrison struggled to translate them in his mind into English - "is this area here which, if I have read your papers correctly, is a crucial node of the neuronic network."

"No two brains are exactly alike," said Morrison. "I can pin down nothing with certainty, all the more so if the particular brain in question is one I have never studied. Still, I would say the area you're heading for looks hopeful."

"Good, as far as that goes. And if we get to my destination, will you be able to tell more accurately whether we are at a crossroads where several branches of the network meet or, if not, in what direction and how far such a crossroads might be?"

"I can try," said Morrison cautiously, "but please remember that I have made no guarantees as to my abilities in this connection. I have not offered you any promises. I have not volunteered -"

"We know that, Albert," said Boranova. "We ask only that you do what you can."

"In any case," said Konev, "that's where we're going as a first approximation and we'll get there before long, even though the current is slowing. We are, after all, almost down to capillary size. - Strap yourself in, Albert. I'll let you know if I need you."

Morrison managed to operate the seat belt without any help, proving that even small triumphs can be sweet.

Almost to capillary size, he thought, and looked out through the walls of the ship.

The vessel wall was still at a comfortable distance, but it had changed in appearance. Earlier, the steadily pulsating walls had been rather featureless. Now, however, Morrison could make out no pulsing and the walls were beginning to look faintly tiled. The tiling, Morrison realized, consisted of the cells that made up the thinning walls.

He could not actually get a clear look at the tiling, either, for the red corpuscles were in the way. They were now soft bags nearly the size of the ship. Occasionally, one ballooned past the ship at close quarters and was pushed elastically inward at the point of contact, without undergoing any visible harm.

One time a small smear was left behind. Perhaps the contact had been just a little too forceful and a line of miniaturized molecules had been formed against the hull, Morrison thought. The smear lifted off quickly, however, and dissolved in the surrounding fluid.

The platelets were another story, since by their very nature they were much more fragile than the red corpuscles.

One made a head-on collision with the ship. Or perhaps it had been slowed by a collision with a red corpuscle so that the ship had overtaken it. The prow of the ship penetrated deeply and the skin of the platelet punctured. Its contents oozed out slowly, mixing with the plasma and then forming into two or three long strings that tangled with each other. They clung to a portion of the ship's hull for quite a time, trailing behind.

Morrison waited to see any evidence of a clot forming. None did.

Minutes later Morrison saw, up ahead, a milky fog that seemed to fill the blood vessel from wall to wall, pulsating and undulating. Inside it were dark granules that moved steadily from one side to the other. To Morrison, it looked like a malignant monster and he couldn't help but cry aloud in a moment of terror.