Morrison said, alarmed, "How far will we miniaturize?"

His words were overborne by Kaliinin's shrill command. "Arkady, move it forward. Gently! Just put forward pressure on the ship."

"Yes, Sophia - but tell me when to stop." To Morrison, he added, "My father used to say: 'Between not enough and too much is a hair's breadth.'"

"More, more," said Kaliinin. "All right. Now we'll try." The ship seemed to stick and strain and then it suddenly slid forward and Morrison felt himself thrust gently back against his seat.

"Good," said Kaliinin. "Just a little less now."

The cell came to an end. Beyond it was another cell. Thin cells, as cells went, a mere film of cells, fitted together to make a tiny tube, with the ship and its crew of five clinging to the inner surface by minute attractions of electric charge.

The space between the adjoining cells seemed ropy, with cables stretching from inside one cell to the other. They were not all intact and there were stumps visible like the remains of a felled forest. It seemed to Morrison that there were narrow gaps in that felled forest, but he couldn't see clearly from the angle at which he viewed them.

He said again, "How far will we miniaturize, Arkady?"

"Eventually to the size of a small organic molecule."

"But what would the chances be of spontaneous deminiaturization at that size?"

"Appreciable," said Dezhnev. "Much more than it was when we were the size of a red corpuscle or even of a blood platelet."

"Still not enough to worry about," said Boranova. "I assure you."

"Exactly," said Dezhnev and raised his hand slightly with the first two fingers crossed so that Morrison could just see it and Boranova, farther back, could not. That American gesture had become universal and Morrison, knowing exactly what it meant, felt himself growing cold inside.

Dezhnev was looking straight ahead, but he might have sensed Morrison's grimace or heard his soft grunt. He said, "Don't worry about it, young Albert. It is always wise to have but one worry at a time and right now let us worry about squeezing out of the blood vessel. - Sophia, my loved one."

"Yes, Arkady," she said.

"Weaken the field in the rear of the ship and when I move grope for one ahead."

"I will do so, Arkady. Didn't your father once say: 'There is no point in trying to teach a thief to steal'?"

"Yes, he did. Steal, then, little thief, steal."

Morrison wondered whether Dezhnev and Kaliinin were deliberately being lighthearted in the face of the possibility of sudden death as a way of cheering him up? Or were they showing contempt for his cowardice? He chose the former. Surely when an action might equally well be interpreted as friendly or hostile, one might as well choose the friendly. Perhaps Dezhnev's father would have agreed. With that thought, he felt cheered.

The ship's rear seemed to be hanging loosely and to remain several centimeters (several picometers in real measure?) from the wall of the capillary. Morrison studied it closely and could see the serried ranks of protein and lipid molecules that made up that wall.

He thought, What are we doing ignoring this? Here is our opportunity to study tissues with greater precision than the best scanning electron microscope can - and to study them while alive; to see not only position but living change and motion. We have passed through the bloodstream and narrowed in on a capillary wall without looking at anything in any real scientific sense. We are only passing through, with no more interest than we would show if we were in a subway, barreling through an underground tunnel. - All to study oscillations that might be produced by thought… and might not.

The ship was inching along (an old word, thought Morrison suddenly, antedating the metric system, but he'd never heard anyone say "centimetering along") as though it were somehow feeling its way. Perhaps, between Dezhnev's motors and Kaliinin's flickering electric fields, that was precisely what it was doing.

"We're approaching the junction, little Sophia," said Dezhnev in a curiously tight voice. "Make sure your hold is firm in front, while I move forward another meter or so."

"I suspect from the appearance and electrical behavior," said Kaliinin, "that we have a clump of arginines toward the junction. That represents a strong region of positive charge and I can handle that as smoothly as sour cream."

But Boranova said sternly, "No overconfidence, Sophia. Keep a firm watch. If you miss and the ship tears loose, there will be much to do over."

"Yes, Natalya," said Sophia, "but with all respect, the warning is not really needed."

Dezhnev said, "Sophia, do exactly what I say. Keep only the prow of the ship attached to the wall, but strongly. Release everything else."

"Done," said Sophia faintly.

Morrison found himself holding his breath. The rear of the ship had spun away from the wall, but it held in front. The bloodstream caught the detached rear end and pushed the ship into a position at right angles to the current, while the capillary wall, where the ship still held, moved outward like a pimple.

Morrison said tightly, "Watch out. We'll pull a section out of the wall."

"Quiet, all!" thundered Dezhnev. Then, in an ordinary voice, "Sophia, I shall increase the engine push slowly. Get yourself in position to break all remaining attraction. The ship is to be entirely neutral - but not until I say so."

Sophia cast a quick look toward Boranova, who said in her quiet way, "Do exactly as you're told, Sophia. For this, Arkady's word is absolute."

Morrison imagined he felt the ship straining forward. The section of the capillary wall to which it was attached stretched farther and farther.

Sophia said urgently, "Arkady, either the field will snap or the wall will."

"Another moment, dear one, another moment. - Now."

The wall snapped back and the ship bounded forward in a great leap that rocked Morrison gently backward. The forward end of the ship buried itself in the cement stuff between the two cells of the capillary wall.

52.

For the first time, Morrison was aware of the laboring of the microfusion engines. There was a subliminal throbbing as the ship worked its way through the joint with what seemed increasing difficulty. There was nothing to see up ahead. The thickness of the capillary wall, very thin though it was in normal terms, was far thicker than the length of the ship.

The ship was now totally immersed in the joint and Dezhnev, beads of sweat on his forehead, turned his head and spoke to Boranova. "We're using up energy faster than we should."

Boranova said, "Then stop the ship and let's consider."

Deshnev said, "If I do that, there is a chance that the natural elasticity of this material will pop us out of the joint and back into the bloodstream."

"Slow the engines down, then. Choose a level that will be enough to keep us in place."

The throbbing came to an end.

Dezhnev said, "The joint is exerting considerable pressure on the ship."

"Enough to crush us, Arkady?"

"Not now. But who can say for the future if the pressure continues."

Morrison burst out. "This is ridiculous. Didn't someone say we're the size of a small organic molecule?"

"We're the size of a glucose molecule," said Boranova, "which is made up of twenty-four atoms altogether."

"Thank you," said Morrison freezingly, "but I know how many atoms there are in a glucose molecule. As it happens, small molecules drift through the capillary walls constantly by diffusion. Diffusion! That's the way the body works. Why aren't we diffusing through?"

Boranova said, "Diffusion is a statistical proposition. There are twenty-four billion trillion glucose molecules in the bloodstream at any given time. They move around randomly and some manage to hit in such places and in such ways as to move through a joint, or to move into the membrane of a capillary wall cell, into the cell, and out the other side. A very small percentage succeed at any given second, but that is enough to ensure proper tissue functioning. However, by chance, a particular glucose molecule may remain in the bloodstream for a month without diffusing. Can we wait a month for a chance to do its work?"


Перейти на страницу:
Изменить размер шрифта: