Ocean on Top

by Hal Clement

  Nothing was more likely than that he would think of some final questions he wanted to ask Bert, and he would certainly know where to meet him. Evidently Bert was no better a schemer than I was, but that was very little comfort at the moment.

  Marie saw him before either Bert or I could think of anything to do; the sub suddenly left its swimming guide behind. Seconds later its water jets sent us spinning as it came to halt in front of our group. Yes, Marie had seen Joey. Her politeness with the savages had evaporated.

  I had been hearing my own heartbeat and those of people near me for some time now, but I hadn’t realized until this moment how loud that beat could be.

  Marie’s voice, though, turned out to be louder. Her first words weren’t just the ones I would have expected, but I’ve already admitted that she thinks a good deal faster than I do. Not always in the same direction, or even in the right one, but faster.

  “Joey!” It ought to have been a howl of surprised welcome, but even the peculiar acoustical situation left me pretty sure it wasn’t. It’s hard to believe that a girl known to have gone so completely overboard for someone could address him in the tone of a stern aunt, but the resemblance was there. “Joey, how long have you known that I was here?”

  Joey looked around for the writing pad; I was delighted to hand it to him and in no hurry to get it back.

  “I didn’t know until this moment,” he wrote.

  “How long have you known that Bert was here?”

  “A few weeks. I don’t remember exactly. Within a day or two of the time I got here myself.”

  I could guess what was coming next, but fortunately for me I was wrong.

  Marie was not a technician. She can run a sub in the ordinary course of duty, naturally, but she is not really familiar with all the handling and operating gear carried by a work sub. For that reason, I’m still completely mystified how she managed to coordinate her next move so perfectly. One of the smaller handling tongs popped out of its recess and caught Bert neatly around the neck, and only when he was firmly gripped did she follow the action with words.

  “You dirty liar! You slimy piece of trepang! I ought to twist the head off your crooked neck! If it were possible I’d throttle you here and now! You knew why I came and who I was looking for. You knew he was here. You didn’t tell him I’d come, and you lied to me about having seen him. You twisted poor Tummy so that he followed your own crooked line!”

  I somewhat resented the implication that I hadn’t brains or initiative enough to be held responsible for my own actions, but I was able to resist the temptation to break in and insist that part of the plan was mine. I didn’t even object to her use of one of my more odious nicknames. I just let her words run on.

  I won’t quote any more of them; as I’ve said already, I promised her not to. I was a little sorry for Bert, since the grip on his neck must be hurting, but as Marie herself had said she couldn’t very well strangle him under the circumstances. I was sure she wouldn’t if she could have. Not Marie. The others seemed rather concerned, though. The girl and her regular companion flung themselves at the extension arm and wrenched at it uselessly. The doctor tried with equal lack of success to pry the tongs from around Bert’s neck. Joey knew better than to do either, but he was clearly bothered; he waved and shook his head at Marie in an effort to convince her that she should stop. It was the sort of scene which should have been accompanied by lively music, screams, the thump of fists, and the crash of broken glass; but it all went on in ghostly silence.

  No screams, which were impossible; no fists, which couldn’t move fast enough in this medium to make much of a thump anyway; no apparatus within reach which was fragile enough to be damaged by the gracefully thrashing bodies.

  It was Joey who managed to bring it to an end. He was still holding the writing pad, and he hastily printed on it in the largest letters that would fit, “YOU’RE KILLING HIM!”

  He held this against the conning part so Marie could see practically nothing else.

  It took a few more seconds, but she suddenly got her senses back and released the tongs. Bert’s face was purplish, and he had lost consciousness; the doctor grabbed his wrist, I thought to check pulse, but in fact simply for a tow bar. The two of them disappeared into the operating room.

  I hesitated for a few seconds, unsure what was most important, and then went after them. The girl and her friend followed me; Marie’s guide stayed outside with the sub. Joey, after looking as though he would come along, changed his mind.

  In the operating room Bert was quickly fastened to the table, and the doctor got to work.

  Strictly speaking he wasn’t a doctor, as even I realized; there can be no doctors in a population of a few thousand people which has been separated from the mainstream of human knowledge for three or four generations. He was a darned good technician, though, and fortunately was working right in his own field. He did know that heart-lung machine cold, and he knew the general run of troubles involving the human breathing and circulatory systems. Interfering with the coughing reflex, as these people had had to do for their pressure-survival system, had produced some fallout along those lines. There were controls for the machine and its auxiliary gear inside the room, presumably in parallel with the remote ones. Quite evidently depressurization wasn’t the only purpose of the apparatus.

  In something under sixty seconds the tech had Bert plugged into the gadget, and his color was coming back to normal. Then, in more leisurely fashion, other instruments began looking and prying down his throat.

  Apparently very little real damage had been done there, though the outside of his neck was starting to discolor into one huge bruise. In less than five minutes the doc — I’m going to call him one, under the circumstances — withdrew his equipment and used a hypodermic on his patient’s upper arm. The needle must have contained a stimulant, for Bert opened his eyes almost at once.

  It took him only a few seconds to get oriented. Then he fixed his eyes on me and actually blushed. He was still a little confused, because he started to speak. The pain in his chest as he put pressure on his liquid-filled lungs brought him back to reality. He looked around and made writing motions. The doctor didn’t seem to mind, so I went back for the writing pad, which Joey still had.

  I didn’t have to interrupt a conversation to take it. Joey wasn’t writing, and Marie wasn’t talking.

  Apparently nothing at all had been said during the crisis in the operating room — we’d have heard Marie’s voice even there, and Joey’s three words of a few minutes before were still on the pad. Marie was looking at him through the port, and he was looking everywhere but at her. I didn’t pause to do any analysis. I just took the pad from Joey and swam back to the table.

  The doctor called Bert’s attention to the blood connections between him and the machine, but made no real effort to stop him from writing. Bert nodded an acknowledgment of the warning and went ahead with the stylus. He wrote briefly, and handed the pad to me.

  “I’m sorry, but I can see when I’m checkmated. I hope your luck is better, though now that she knows Joey is alive I wouldn’t bet on it. Tell her she didn’t kill me, if you think the possibility is bothering her. I’d better not see her again myself.”

  That was an eye-opening paragraph. Suddenly I saw just why Bert had been trifling with the truth, why he had concealed Joey’s presence from Marie, why he had decided to go back to the surface on such short notice, why he had been so far from completely frank with me — and even why the local Council had been so reluctant to let us both leave.

  I also saw that I was in no position to criticize him for any of it. There was not a word to be said against him which didn’t apply with equal force to me. The only reason I hadn’t done as much, under exactly the same motivation, was that I’d been in no position to.

  I couldn’t blame him, or even criticize him. I have failings, but I’m not that much of a hypocrite. I could be sorry for him; as he’d said, his chances were gone.

 
Marie might conceivably come to realize that Joey was a hopeless case as far as she was concerned, even after this discovery that he was alive after all. She might possibly settle for me if that happened. But after the last few weeks and the discoveries of the last few minutes she’d never, never have any use for Bert.

  I gave him as sympathetic a look as I could as all this dawned on me, but I could think of nothing to write. He answered with a bitter grin and waved me toward the door. I went. The others, except the doctor, followed me.

  Chapter Twenty-four

  I wasn’t through learning for the day, though. As I went through the huge valve and became visible from the tunnel outside, Marie’s voice met me. It had sharp edges, but otherwise it resembled a heavy club.

  “Just where did you come up with the idea that these people weren’t getting oxygen through their lungs? If I killed Bert I’m not too sorry, but it’s your fault.”

  Even I had had time to see that this question would be coming, but I’d had no chance to work out a very good answer. While the doctor had been working on Bert I’d been doing the same with my memory. It was evident enough that my theory of oxygen-food was out the window, but I still wasn’t able to find a better one.

  All I could do was repeat the theory and my reasons for it. I also assured Marie that she hadn’t actually killed Bert. Somehow my reasoning didn’t look as airtight written out as it had felt when I was thinking it through in the first place — quite aside from the fact that it was now obviously wrong. In spite of this, Marie seemed to calm down as I wrote page after page, let her read each, and cleared it and went on to the next. The forced pauses may have helped.

  I admit you convinced me before,” she said when I was done, “and I don’t see what the hole is myself. Joey, in the time you’ve been here have you found out enough to let you tell us what’s wrong with this notion?”

  “I think so,” he wrote. He paused, and positioned himself outside the port so that Marie could read as he wrote. I swam to a spot a little further above and behind him, so I could do the same.

  “Your big mistake was natural. You were quite right in observing that we aren’t breathing, as far as chest motions go. But in spite of that we are getting oxygen from this liquid. It’s wonderful stuff. You might regard its molecular structure as vaguely comparable to hemoglobin in that it binds oxygen molecules loosely to its surface. I don’t know just how many, but the number is large. It doesn’t have the porphyrin groups of hemoglobin; they went to great lengths to make it transparent to visible light. I couldn’t draw you its structural formula from memory. But I’ve seen it. It’s perfectly understandable.

  “Now, think a minute. Liquid oxygen has a molecular concentration about four thousand times that of the gas we normally breathe. The reason we have to breathe is that diffusion, at sea-level concentrations, won’t get enough oxygen through your windpipe to keep an animal as large as a human being going. You can’t live in liquid oxygen, of course, because of temperature problems. However, in this liquid the concentration of almost-free oxygen is far, far higher than in the atmosphere — a long way short of what it is in LOX, but very high. That was another problem; while they were at it, they made the kernel of this molecule with a structure which would break down endothermically at temperatures above a few hundred degrees. A fire will tend to damp itself out, therefore. But that’s a side issue, as far as breathing is concerned.

  “When molecules of the stuff give up their oxygen in your lungs, nearby molecules pass on more O2 to the ones which have lost it; others replenish those, and so on. It’s a bucket-brigade situation, but it’s described by just the same equations that you’d use for a diffusion problem. The rate of oxygen transport depends on the concentration difference between the inside of your lungs and outside, and on the area of the barrier through which the diffusion is taking place — in this case, the smallest cross-section area of your windpipe. In this case, the oxygen concentration around us is enough to keep us going by diffusion down our windpipes. I’m not sure about carbon-dioxide elimination, but I believe your theory is more nearly right there; it’s taken care of by binding into insoluble carbonates in the intestines and gotten rid of as solid waste. As I say, that seems a little funny to me, and I may have misunderstood what I read about it. I’m going to dig into the matter more when I have time. I’m no physiologist, but it’s fascinating reading, especially the history of its development.”

  “But why such a fancy arrangement? A less efficient oxygen carrier would still work as long as you pumped fresh supplies into your lungs! That’s why we breathe, anyway!” Marie couldn’t have been thinking at the top of her form just then; even I could see the answer. I took the pad from Joey — in fact, he held it out to me, with a suspicion of a grin on his face — and started my own exposition.

  “Pumping a liquid even denser than water through your windpipe would call for tremendous effort and probably dangerously high lung pressures. I tried it just after I made the change, and I know it hurts. I wouldn’t be surprised if you could rupture lung tissues that way. It’s a logical chain: fill body cavities with liquid so that outside pressure can be matched without serious volume change; then you can’t pump the liquid with your normal breathing equipment; so you have to give it a high enough free-oxygen concentration to diffuse an adequate supply down your throat. Simple once you see it. What’s the primary source of oxygen, though, Joey?”

  “Just what you’d expect. Photosynthesis. That’s where most of the power produced here goes. About three-quarters of the oxygen comes from gene-tailored algae living at the interface between the ocean and the breathing liquid. The rest comes from the farm plants. Loss to the ocean is low because of the favorable partition ratio.”

  I took the pad again.

  “Well, at least I was right in guessing why laughing is dangerous, and why they do away with the coughing reflex; either action could rupture your lungs.”

  “Of course,” agreed Joey. “I don’t claim to know the whole story yet — even Bert, who’s been here much longer, probably doesn’t. Remember, all we could learn about it was what we read, and that was only what happened to be lying around written in languages we knew. We weren’t told any of it by these people. Not only is it impossible to talk to them on such a level; I’m pretty sure most of them don’t know it either.

  How many people at the surface, out of any given fifteen thousand, would be doctors or physiologists or even engineers?”

  “That’s why they need us so badly,” I interjected. “Bert must have told you about that.”

  “Who’d believe Bert?” snapped Marie — we’d been holding all our writings so she could read them, of course, even when they weren’t specifically meant for her. Joey took over the pad.

  “You’d better. Whatever he said about these people being ready to do almost anything to keep technically skilled visitors down here is probably true. From what I’ve been able to make out in the last few weeks, unless some very extensive work is done on this installation quite soon, there’ll be twelve or fifteen thousand people migrating back to the surface and asking for their power ration in the next couple of decades.”

  “How could they have the gall to do that?” Marie asked in scorn. “They’ve been down here all their lives, squandering power that should have gone into the world network and shared with the rest of us. They’re just like those old French aristocrats with their ‘Let ’em eat cake’ attitude — except the aristocrats would have been too proud to come begging the Jacquerie for crusts if their own wealth vanished.”

  “That was my first reaction, too,” Joey wrote imperturbably. “I got myself pressured for the same reason Bert and you” — he nodded to me — “did; I planned to investigate as completely as possible and send up a report that would have the Board down here civilizing this place in a month. By the time I had enough data for a meaningful report, though, I realized it would be useless. The Board wouldn’t do anything about it.”

  “That’s what
Bert claimed,” I put in. “He said that such reports had been sent back before, decades ago, and that nothing had come of them.”

  Joey reclaimed the pad.

  “I never ran into any accounts of that sort. Bert and I wouldn’t have looked for just the same material, though, anyway. My point is that the Board can’t do anything about it.”

  “Why not? Look at all the energy going to waste down here!” interjected Marie.

  “Think again, girl. It’s not going to waste any more than the power used by natural plants on the surface for photosynthesis is going to waste — far less, in fact. It’s true that you can divide the power output of this installation by the local population figure and come up with a figure many times the normal per capita energy ration; but by far the greater part of that power goes into the lights. If you cut any significant percentage of the lights, you drop the photosynthesis rate to a level where there won’t be enough oxygen for the present population. If you cut the population by much, even the shaky maintenance that the outfit has now will degenerate, and, as I said, the place will have to shut down.

  “You may criticize the decision the ancestors of these people made three or four generations ago. I agreed it was highly immoral by our standards. However, the current population is simply stuck with the consequences, and at least they’re not drawing from the planetary power net. They’re on their own, except intellectually. It seems quite in line with duty, to me, to stay here and help them. You’ll have to make your own choice.”

  Marie was silent for half a minute or so, wrapped in thought. When she spoke again, it seemed to be a change of subject.

  “Why did Bert lie to me? None of what you’ve been pointing out — which I can see makes sense — seems to call for it.”

  Joey shrugged.

  “I have no idea. Remember, he didn’t tell me you were here, much less anything else connected with you. I don’t know what he had on his mind.”