Noise

by Hal Clement

  There was a similar ring on this side, which she took in her own right hand. Then she pointed back to the other side, extended fingers successively in a one-two-three gesture, and simulated pulling the ring herself.

  Mike nodded comprehension, swam back to the first ring, and took hold of it. Wanaka made the gesture of approval he had seen earlier, which had clearly originated on Earth but not in any Polynesian culture, and repeated the one-two-three signal, pulling her ring at “three.” Mike did the same. He was not too surprised to see two rubbery sacks rather longer than the cabin floor begin to swell very slowly. The importance of backup had apparently taken a firm hold on Kainui. One could see why.

  He had already learned that sailing craft were extremely expensive here, simple as their basic growth ought to be; now he began to see why that was, too.

  The expansion of the floats was so slow that he wondered why it had been important to start both of them at once, but he never remembered later to ask. The captain swam to what Mike still thought of as the after end of the cabin, pointed out two more rings much closer to its center line, and they repeated the coordinated pull. Two more floats began to swell.

  It took fifteen or twenty minutes for the filling gas bags to lift the cabin clear of the sea. Mike assumed that the gas was not coming from pressure tanks but was being generated by some form of pseudolife. There would be no way to ask until they got out of the water, however. There seemed no immediate prospect of that; all three of the crew, aided by the unskilled passenger when he could be shown what to do, were engaged in what were presumably life-or-death tasks as Malolo gradually was transformed from a sailing catamaran into something of dubious drive source, with its former mast divided in two—there were telescoping sockets along it—to form cross members connecting the remaining hull with the cabin, making the latter a highly inefficient-looking outrigger. There were connectors in the right places for this job, too.

  Wanaka did not abandon the separated deck, to her passenger’s curiosity. This had tipped back to horizontal and floated awash when the mast stays had been cut. It seemed incapable of carrying anything useful; even little ’Ao’s weight pushed a side or corner under the surface unless she balanced herself very carefully at its center. She was amusing herself trying this when the captain ordered her rather sharply to get back to work.

  The three adults were now all out of the sea on the remaining hull; it was not necessary to use hand language. Mike could interpret tone as well as words. The child complied instantly without even looking indignant. Her doll, once more perched on her shoulder, made no comment either.

  Mike, fully appreciating his own ignorance, decided not to ask about the deck just then. Also, he kept quiet on another point: after sunset there had until now been a light at the top of the mast whose purpose seemed obvious, but there was no suggestion of replacing it on, say, the roof of the cabin, though even the fainter sun was now almost below the horizon. He wondered what the chances might be of their being run down by another vessel in the dark.

  His reluctance to look ignorant overweighed his slight worry that the others might actually have overlooked that matter. Once the still floating hull had been attached to the sections of mast and the latter in turn to the floating cabin, he entered with the others and settled down to the usual evening activities.

  “Usual” was not quite the right word; it was the first time all four of them had been inside at once for more than a few seconds since leaving Muamoku. Also, there was much more than usual to do with the life-support equipment. Mike couldn’t help much with this, but watched and listened to explanations, mostly from ’Ao, as the adult crew members toiled. The least pleasant of the explanations made it clear that they would possibly be eating suit-type synthetics until further notice once the parting gifts from the other ship had been used up. The pseudoplants that produced the more palatable substances might or might not survive their recent immersion; they had been on the deck, and Keo had not gotten them out of the water immediately. The realization that the suit synthetics had been most carefully designed to provide all possible human nourishment needs for an indefinite period did not offset the evident fact that taste had not been considered in the listing of those needs.

  Or possibly, Hoani told himself, the notions of what tasted good had also diverged in the last few generations from Earth-human-normal. He promptly corrected that term in his mind to Hoani-personal-normal. There is a broad spectrum of “normal” human tastes.

  Eventually the most urgent tasks seemed to be done, and everyone ate once more, quite slowly this time. Then the child was firmly gestured toward her hammock, and Keo without orders tumbled onto a bunk. Mike decided it would be tactless to claim the other, even though Wanaka showed no signs of being ready for it. She settled down to paperwork—Malolo’s log, mainly. Mike began to put his own copious mental notes of the day into permanent form, up to the minute.

  He finished before Wanaka did, but eventually she stopped writing, too, and looked up from her desk.

  “A nonstandard day,” she remarked with no sign either of annoyance or humor. “You must have a few questions.”

  “Some,” he admitted, “but I’m figuring out quite a bit for myself. If the kid isn’t going to spend any more time at a masthead, maybe you could have her start teaching me Finger.”

  Wanaka nodded. “Good thought. I doubt that either Keo or I will be able to give you as much attention as we hoped.”

  “That’s all right. She knows enough more than I do to be an appropriate teacher anyway. But I can’t help wondering whether she could tell me much about what turns the oxygen I heard Keo mention into a danger. I could only infer from the spoken words after the episode under the hull that she didn’t know as much as she should about it, so maybe you should tell me.”

  The captain smiled wryly. “She can tell you as much as either of us could. She was dangerously careless, and I had to downgrade her for it. But I may as well give you the picture.

  “It’s nasty stuff. You probably know that not everyone on Kainui is completely agreed about everything.”

  “I’m ready to take that for granted. You’re human.”

  “Some people want to get a lot of oxygen into the air and at least get rid of the carbon monoxide. This, to be managed in less than a good many generations, would require pseudolife able to reproduce itself indefinitely—the sort of thing we told you back at the iron-fish that most of us consider unacceptably dangerous. Others remember too clearly the unforeseen side effects of that sort of seeding on a lot of worlds, including the Old one. The result, since there’s never been any way to stop people from using knowledge once it’s been acquired, is that some folks, and some whole cities, have gone ahead designing and releasing pseudos able to break down water, and others to take the oxygen and react it with CO before the freed hydrogen made a nuisance of itself, interfering with the redox we use in the city and on board here. Usually these things have been grown as symbionts. Unfortunately, while officially designed systems have so far behaved fairly well, some of those designed by hackers—individuals with less interest in social approval than in displaying their own skill—have gotten loose with some pretty sad side effects. No doubt their planners meant well, but having to keep a project more or less under water divides attention, and not knowing what other people were doing in the field—well, you’ve probably heard the story of a couple of nations having political disagreements back on the Old World. One of them sabotaged the guidance system of a missile being tested by its enemies, and targeted its makers’ capital, not knowing that another department of its own government had already sabotaged the warhead. Not an unusual event in complex societies, or even in our quite simple ones.”

  “So there are oxygen-producers loose on the planet, not all of them putting their product to its best use.”

  “Exactly. And several types will leave the oxygen free to attack many other sustances than carbon monoxide. For the last couple of centuries cities as well as shi
ps have had to keep a constant watch for such stuff. Nowadays we also have to watch out for people who dream up organisms which will act as predators for such oxygen-producers. These also, of course, have to be unlimited breeders. I’ve heard an old aphorism about the perils of riding a tiger, and I can see its implications even if I can only guess what a tiger is.

  “Anyway, we’ve picked up a dangerous oxygen-maker. It’s lucky it takes so much energy to break up water, and the things that don’t dispose of the oxygen properly usually don’t get much of it back. I do wish I could promise we could get you back to Muamoku. But we told you about that before we started.”

  “You did. No blame. I may have been safer crossing nineteen hundred parsecs between the stars, but I doubt it.”

  “Anything else you’re curious about?”

  “Lots, but you couldn’t cover it in one night. I gathered the kid did something out of line? Part of what went on was in Finger, and most of the rest out of my hearing in the thunder. Don’t give me details that you consider none of my business, but I wouldn’t want to make any verbal slips that might either bother the kid or undercut discipline.”

  Wanaka glanced at the hammock and gave a terse account of what had happened. She skipped her own doubts about the punishment, since she was not completely certain that ’Ao was asleep. More to the point, she was quite certain that the doll wasn’t.

  Mike nodded as she finished. “All right. Remaining worry: just how sure can we be that that gangrene was confined to the hull we’ve shed?”

  “I rather expected you to ask that. If you were wearing a rank badge I’d award you a couple of points. We aren’t sure at all. My guess is that when we hit that whatever-it-was a while back—you remember—we picked up the infection. We’ll never know just what the object was, but I’d guess either an egg designed to make oxygen seeds or more likely a bit of coral which had been around long enough to pick up practically anything. Viruses grow best on a solid surface, almost always. We pushed off the old hull, and I hope it sinks; but we’ll have to check the one we still have carefully and frequently from now on.”

  “Something just occurred to me. If oxygen-producing pseudos aren’t capable of direct reproduction, couldn’t Malolo’s breathing equipment get infected?”

  “It could. We carry several carefully packeted seeds for replacing that gear; and another possible source of our present infection would be a minor mutation of such a seed lost from another ship.”

  “Or maybe our own? Infecting from inside the hull?”

  Wanaka raised an eyebrow, but showed no indignation. “That’s conceivable, and we’ll check. The seeds were, and I think still are, in the cabin, though. Thanks for the idea—I guess.”

  “And if the other hull goes, too? I was very impressed by your built-in trouble preparations, but there must be a limit to what they can handle.”

  “There is.” The captain offered no more details, and Hoani decided not to press the point. He himself felt that knowing the worst was no more likely to bother him than not knowing anything, but Wanaka was the captain and he, by now, was quite clear about most of the implications of that fact. That was one reason why he had hesitated earlier before asking about ’Ao’s offense.

  Wanaka went on, “I’m going to sleep. Since we aren’t under way, there’s no risk of hitting anything, and if anything hits us there’s not much to be done about it at night. Sorry, but you’ll have to sleep on the deck.”

  “The one outside? Is that why you kept it?”

  “No. The deck—floor—in here. Your breathing gear wouldn’t last outside. I’m sorry if you don’t sleep well, but we could be sorrier if I don’t. Au ahiahi.”

  Mike did not, in fact, sleep very well. He was pretty sure that the chance of being struck by anything must be considered negligible by the professionals, since they had both retired without setting up a watch, but he frequently found himself awake and listening.

  There was as usual plenty to hear, much of it muffled by the cabin walls, but none of it was informative. He could only guess how much of the night he spent awake, but did not feel very capable when the other adults sat up almost simultaneously. It was dawn, though neither sun was actually up. Kaihapa had not shifted visibly, but that was no surprise; it would have implied hundreds of miles of longitudinal drift in a few hours, which would in turn have called for a most impressive sequence of storms.

  The captain left the chamber briefly, and returned with a report that somewhat eased Mike’s indefinite worries.

  “The old hull’s either sunk or drifted away. Keo, check what we have left for infection, then come back and eat, and we’ll set up the deep-sail and seed. Mike, how good are you at knots?”

  “Hardly up to your standards, I’m afraid. But I have sailed on Earth.”

  “I know. All right. When Keo gets back we’ll wake up ’Ao if she’s still asleep, and she can join Keo and me. I’m afraid you have to stand—and I do mean stand—watch on the other hull, Mike.”

  Hoani realized that the “I’m afraid” part of the sentence was pure courtesy to a guest; he’d actually been given an order. He acknowledged it appropriately.

  Keo was fully twenty minutes at his hull check, but finally reappeared to say that everything seemed to be clear. Mike, the captain, and the now awake ’Ao all noticed the choice of words, but no one remarked on them. They ate, checked their own and each other’s breathing equipment, and went outside. Hoani would have liked to watch what the others were doing, but controlled his curiosity, swam to the hull and climbed onto it, and promptly had his attention taken from the others.

  The sea legs he had acquired earlier were now out-of-date. The hull was less than two meters wide, and responded very differently to swells and microtsunamis than the catamaran configuration did. Also, there was much less to hold on to when he stood up. By the time he was actually able to get his attention away from his own feet, the others were all under water. He hoped he could find one of them if he had anything to report.

  It was the most boring morning he had spent since leaving Muamoku. It was also the most tiring; standing in the one-third gravity was not burdensome even in noise armor, but the constant change of stance needed as the hull pitched, yawed, and jumped called for equally constant muscle work. He was quite proud of himself when the others surfaced and joined him; he had not fallen overboard even once.

  He yielded to temptation and watched the final operation of the others rather than their surroundings. The deck—the original one—had been moored to the stern of the hull the night before; now an additional line was strung between it and the cabin. Keo took the hull end of what had now to be considered a control line, while Wanaka worked her way onto one of the cabin’s floats and juggled with a second. Very gradually, Mike saw, a short and feeble wake appeared at the bow ends of hull, floats, and deck. Something was pulling the whole assembly, very slowly, aft, or at least keeping it from moving with the southeast-bound surface current.

  A few minutes of watching and thinking provided him with a reasonable guess, and encouraged him to ask a question of Keo.

  “How deep is the sea anchor, and how can you keep it there?”

  The native answered without taking very much of his attention from the tow line.

  “Between seventy and eighty meters. We’ve weighted it with some of the iron, and floated one corner to keep it more or less vertical, and attached the smaller sail to help handle the high corner. It was tricky arranging, and if we lose too much of the speed difference between the deep and surface currents it’s unstable. If it goes too far down the whole vertical line of floats will collapse under the pressure and let the stuff sink, and we’ll have to set it up all over again. As long as we’re being pulled hard enough one way by the surface current and the other by the deeper one, the difference should tend to keep the whole thing up.”

  “Why the current difference? Though I think I can guess.”

  “Surface current is diluted water from the equatorial rain b
elt. It gradually picks up salt as it flows. The deeper one is saltier stuff returning toward the equator. That’s a gross over-simplification, by the way.”

  “I thought it might be. How long will this stage take us?”

  “To grow the new hull? Half a year, give or take quite a bit. Depends on temperature and a little bit on ion content of the water. To get to Muamoku afterward? Probably less, unless the captain decides to hunt up more cargo first.”

  Mike found himself out of questions. Both of Keo’s answers needed digesting.

  IV

  Crescendo

  The following weeks ought to have been boring for a person who had never needed much more than an hour to get from one place to another on the same planet, but they weren’t.

  Hoani was a perfectly capable sailor as long as he could see the sails. Wanaka had checked that very early, though she had never left him alone on watch while all the rest were sleeping. The sails, however, were now under water and quite out of sight. Their orientation with the currents they were supposed to be using could be told only from the length of cordage paid out to the various corners, and their depths from the angle at which these lines entered the water. This last was very hard indeed to observe, since they passed through rings on the sides and corners of the deck, which was now floating level with the surface except as waves lifted one corner or another. Two lines, on the nearest deck angles, led to the deepest sail corners, which were held apart by a length of the former mast; not all of this had been used to improvise “outrigger” booms. The peak of the larger sail itself was attached to the center of a shorter such length, whose ends were controlled by lines through rings on the farther corners of the deck. These ends kept separated the longer side of the small sail, while a fifth ring on the deck, midway between the last two, guided the line attached to its apex.