He grinned triumphantly. "Wasn't that well-done?"

"Well-done," said Boranova, "but impossible without what Albert had done first."

"True enough," said Dezhnev, waving his hand. "I give him full credit and the Order of Lenin - if he will take it."

Morrison felt infinite relief. He would not have to go out again. He said, "Thank you, Arkady." Then, rather bashfully, he added, "You know, Sophia, I'm still thirsty."

At once she handed him the bottle, but he hesitated. "Are you sure I'm not drinking more than my share, Sophia?"

"Of course you are, Albert," said Kaliinin, "but more than your share is your share. Come, water is easily recycled. Besides, we have a small additional supply. You did not fit into the air lock neatly. An elbow stuck well out and we had to crack the inner layer and pull it in - which meant the entry of some plasma. Not much, thanks to its viscosity. It's been miniaturized of course and is being recycled now."

"Once miniaturized, it can't amount to more than a droplet."

"That's all it does amount to," said Kaliinin, smiling, "but even a droplet is an extra supply and since you brought it in, you deserve an extra supply. Logic is logic."

Morrison laughed and sucked up additional water greedily, squeezing it out of the flexible container astronaut-style. He was beginning to feel comparatively normal - more than that. He was feeling the kind of dreamy contentment that comes from being freed from the intolerable.

He tried to concentrate, to gain some sense of reality, He was still in the ship. He was still the size of a bacterium, more or less. He was still in the bloodstream of a man in a coma. His chance of living another few hours was still problematical. - And yet, even as he told himself all this, he nevertheless couldn't flog himself out of the feeling that the mere absence of unbearable heat, the mere being with others, the mere existence of a woman's care was, in itself, a touch of heaven.

He said, "I thank not only Arkady but all of you for pulling me in and caring for me."

"Don't bother," said Konev indifferently. "We need you and your computer program. If we had left you out there, the project would be a failure, even if we found the right cell."

"That may be so, Yuri," said Boranova, clearly indignant, "but at the time we were bringing Albert in, I did not think of that, but only of saving his life. I cannot believe that even you were cold-blooded enough to feel no anxiety for a human being who was risking his life to help us, except insofar as we needed him."

"Obviously," muttered Konev, "plain reason is not wanted."

Plain reason was certainly what Morrison wanted. Since the mention of brain damage, he had been testing himself, thinking, trying to come to conclusions. He said, "Arkady, when the microfusion engines are working, you are converting miniaturized hydrogen into miniaturized helium, and some of the helium escapes along with miniaturized water vapor or other materials designed to produce thrust."

"Yes," said Arkady warily. "And if that is so, what follows?"

"And the miniaturized particles - atoms and less - simply escape through Shapirov and through the Grotto and through the Earth and end in outer space, as you told me."

"Again - what follows?"

"Surely," said Morrison, "they do not stay miniaturized. We are not initiating a process, are we, in which the Universe will gradually be filled with miniaturized particles as humanity proceeds to make use of miniaturization more and more?"

"If we did, what harm? All human activity for billions of years could not add a significant quantity of miniaturized particles to the Universe. But it is not so. Miniaturization is a metastable condition, which means that there is always a chance that a miniaturized particle will snap out, spontaneously, to true stability, that is, to the unminiaturized state." (Out of the corner of his eye, Morrison saw Boranova raise a warning hand, but Dezhnev was always hard to stop when in oral flood.)

"Naturally," he went on, "there is no predicting when a particular miniaturized particle will snap out of it, but it is a good wager that almost all will be beyond the moon when it happens. As for the few - there are always a few - who snap out of miniaturization almost at once, Shapirov's body can absorb them -"

He then seemed to see Boranova's gesture, which had grown peremptory, and he said, "But I'm boring you. As my old father said on his deathbed: 'My proverbs may have bored you, but now you can look forward to hearing them no more, so that you will mourn me less and, therefore, suffer less.' The old man would have been surprised - and disappointed, perhaps - to know how much we children mourned him, even so - but I think I won't risk it with my companions in this ship -"

"Exactly," snapped Konev, "so please stop, especially since we are now approaching the capillary that we should be entering. Albert, lean over and study the cerebrograph. Do you agree?"

Kaliinin, carefully addressing Boranova, said, "Albert is in no condition to be badgered with cerebrographs."

"Let me try," said Morrison, struggling with his seat belt.

"No," said Boranova with authority. "Yuri can make this decision his own responsibility."

"Then I so make it," said Konev, looking sullen. "Arkady, can you get near the wall on our right and catch the current that turns into the capillary?"

Arkady said, "I've been racing the red corpuscles and I have caught one that is drifting toward the right wall. It will push us - or the small eddy that is pushing it will also push us. - Ah, you see, it is taking place, just as it did in the previous cases where we had to branch off. Each time I managed to use the natural current correctly." A broad grin creased his happy face as he said, "Applause, everybody. Say, 'Well-done, Arkady.'"

Morrison obligingly said, "Well-done, Arkady," and into the capillary the ship went.

Morrison had recovered sufficiently to be tired of invalidism. Outside the transparent hull of the ship, the wall of the capillary was strongly tiled and seemed fairly close on all sides. It looked very much like the other capillary, the one in which he had turned the ship around.

He said, "I want to see the cerebrograph."

He flung open his seat belt, the first really decisive movement he had made since returning to the ship, and stared rebelliously at the perturbed Kaliinin as he did so.

He pushed himself gently upward into a float, holding himself in position to look over Konev's shoulders by repeated corrections - first up, then down. He said, "How do you know you are in the right one, Yuri?"

Konev looked up and said, "Counting and dead reckoning. See here. If we cut down the scale of the cerebrograph, this is the arteriole we've been following off the carotid. We took this branch and that one, and then it's a matter of counting the capillaries as they branch off on the right.

"We had our run-in with the white cell right here and in the time the white cell had at its disposal, this capillary was the only one it could reasonably have reached. Once we were turned around and got back to the arteriole, we followed its narrowing structure and matched what we saw against the cerebrograpb. The pattern of branch points outside matched almost exactly the pattern described by the cerebrograph and that alone assures me we were following the right path. Now we have gone into this capillary."

Morrison's left hand slipped off the smooth texture of the back of Konev's seat and his attempt to make up for that twisted him into a comic handstand on the outspread fingers of his right hand. He labored to right himself even as he thought, savagely, that another improvement that must be introduced in later versions of the ship would be handholds on the seats and in other strategic areas.