there's nothing else to hold us up. What sort of books do you like?”
“Huh?”
“That head's going to be in a clamp for quite a while. You may or may not like reading, but the only direction you can look comfortably is straight up. Your left hand can work a remote control, and the tape reader can project on the ceiling. I can't think of anything else to occupy you. Do you want some refreshing light fiction, or shall I start you on Volume One of
A regeneration controller is a bulky machine, even though most of it has the delicacy and structural intricacy possible only to pseudolife — and, of course, to “real” life. Its sensors are smaller in diameter than human red blood cells, and there are literally millions of them. Injectors and samplers are only enough larger to take entire cells into their tubes, and these also exist in numbers which would make the device a hopeless one to construct mechanically. Its computer-controller occupies more than two cubic meters of molecular-scale “machinery” based on a synthetic zeolite framework. Mating the individual gene record needed for a particular job to the basic computer itself takes nearly a day — it would take a lifetime if the job had to be done manually, instead of persuading the two to “grow” together.
Closing the gap between the optical microscope and the test tube, which was blanketed under the word “protoplasm” for so many decades, also blurred the boundary between such initially different fields as medicine and factory design. Marco Mancini and Bert Jellinge regarded themselves as mechanics; what they would have been called a few decades earlier is hard to say. Even at the time the two had been born, no ten Ph.D.'s could have supplied the information which now formed the grounding of their professional practice.
When their preliminary work — the “prepping” — on Rick Stubbs was done, some five million sensing tendrils formed a beard on the boy's face, most of them entering the skin near the edges of the injured portions. Every five hundred or so of these formed a unit with a pair of larger tubes. The sensors kept the computer informed of the genetic patterns actually active from moment to moment in the healing tissue — or at least, a statistically significant number of them. Whenever that activity failed to match within narrow limits what the computer thought should be happening, one of the larger tubes ingested a single cell from the area in question and transferred it to a large incubator—“large” in the sense that it could be seen without a microscope — just outside Rick's skin. There the cell was cultured through five divisions, and some of the product cells analyzed more completely than they could be inside a human body. If all were well after all, which was quite possible because of the limitations of the small sensors, nothing more happened.
If things were really not going according to plan, however, others of the new cells were modified. Active parts of their genetic material which should have been inert were incited, quiet parts which should have been active were activated. The repaired cells were cultivated for several more divisions; if they bred true, one or more of them was returned to the original site — or at least, to within a few microns of it. Cell division and tissue building went on according to the modified plan until some new discrepancy was detected.
Most of this was, of course, automatic; too many millions of operations were going on simultaneously for detailed manual control. Nevertheless, Mancini and Jellinge were busy. Neither life nor pseudolife is infallible; mutations occur even in triply-redundant records. Computation errors occur even — or especially — in digital machines which must by their nature work by successive-approximation methods. It is much better to have a human operator, who knows his business, actually see that connective tissue instead of epidermis is being grown in one spot, or nerve instead of muscle cells in another.
Hence, a random selection of cells, not only from areas which had aroused the computer's interest but from those where all was presumably going well, also traveled out through the tubes. These went farther than just to the incubators; they came out to a point where gross microscopic study of them by a human observer was possible. This went on twenty-four hours a day, the two mechanics chiefly concerned and four others of their profession taking two-hour shifts at the microscope. The number of man-hours involved in treating major bodily injury had gone up several orders of magnitude since the time when a sick man could get away with a bill for ten dollars from his doctor, plus possibly another for fifty from his undertaker. The tendrils and tubes farthest from the damaged tissue were constantly withdrawing, groping their way to the action front, and implanting themselves anew, guided by the same chemical clues which brought leukocytes to the same area. Early versions of the technique had involved complex methods of warding off or removing the crowd of white cells from the neighborhood; the present idea was to let them alone. They were good scavengers, and the controller could easily allow for the occasional one which was taken in by the samplers.
So, as days crawled by, skin and fat and muscle and blood vessels, nerves and bones and tendons, gradually extended into their proper places in Stubbs' face and hand, The face, as Mancini had predicted, was done first; the severed hand had deteriorated so that most of its cells needed replacement, though it served as a useful guide.
With his head out of the clamp, the boy fulfilled another of the mechanic's implied predictions. He asked for a mirror. The man had it waiting, and produced it with a grin; but the grin faded as he watched the boy turn his face this way and that, checking his appearance from every possible angle. He would have expected a girl to act that way; but why should this youngster?
“Are you still the same fellow?” Mancini asked finally. “At least, you've kept your fingerprints.” Rick put the mirror down.
“Maybe I should have taken a new hand,” he said. “With new prints I might have gotten away with a bank robbery, and cut short the time leading to my well-earned retired leisure.”
“Don't you believe it,” returned Mancini grimly. “Your new prints would be on file along with your gene record and retinal pattern back in Denver before I could legally have unplugged you from the machine. I had to submit a written summary of this operation before I could start, even as it was. Forget about losing your legal identity and taking up crime.”
Stubbs shrugged. “I'm not really disappointed. How much longer before I can write a letter with this hand, though?”
“About ten days; but why bother with a letter? You can talk to anyone you want; haven't your parents been on the 'visor every day?”
“Yes. Say, did you ever find out what made the
Mancini grimaced. “We did indeed. She got infected by the same growth that killed the zeowhale we first picked up. Did you by any chance run that fish into any part of the hull while you were attaching the sling?”
Rick stared aghast. “My gosh, Yes, I did. I held it against one of the side hulls because it was so slippery… I'm sorry…I didn't know…'
“Relax. Of course you didn't. Neither did I, then; and I never thought of the possibility later. One of the struts was weakened enough to fail at high cruise, though, and Newton's Laws did the rest.”
“But does that mean that the other ships are in danger? How about the
“Oh, sure. It was done long ago. A virus for that growth was designed within a few weeks of its original escape; its gene structure is on file. The mutation is enough like the original to be susceptible to the virus. We've made up a supply of it, and will be sowing it around the area for the next few weeks wherever one of the tenders goes. But why change the subject, young fellow? Your folks
He noticed with professional approval that the blush on Rick's face was quite uniform; evidently a good job had been done on the capillaries and their auxiliary nerves and muscles. “Give, son!”
“It's… it's not important,” muttered the boy.
“Not important…oh, I see. Not important enough to turn you into a dithering nincompoop at the possibility of having your handsome features changed slightly, or make you drop back to second-grade level when it came to the responsibility for making a simple decision. I see. Well, it doesn't matter; she'll probably do all the deciding for you.”
The blush burned deeper. “All right, Marco, don't sound like an ascetic; I know you aren't. Just do your job and get this hand fixed so I can write — at least there's still one form of communication you won't be unable to avoid overhearing while you're on watch.”
“What a sentence! Are you sure you really finished school? But it's all right, Rick — the hand will be back in service soon, and it shouldn't take you many weeks to learn to write with it again…'
