by Hal Clement
Perhaps I haven’t made clear quite all the nuisances involved in rolling the tank. The principle ought to be plain enough; it was simply a matter of letting the appropriate spring push out a leg against the bottom, on the side I wanted to go away from. It may not have crossed your mind that this general method of getting around meant that living equipment, control panels, and other fixed gear were some-
times to one side of me, sometimes to another, and sometimes above or below. There were times when it was very hard to keep from sitting on all the leg-control buttons at once, for example. As I’ve said, the legs were meant more for position and altitude fine control, and to keep the tank from rolling on a slope, than for genuine travel. The need for the latter had not been foreseen, or at least hadn’t been considered very great, by the authorities.
At least, concentrating on working the machine along the bottom kept my mind from the worries I’d felt on the way down. It was actually more likely now that I’d come under unfriendly observation, but at least I wasn’t brooding over it. The swimmers had vanished in the distance, nothing else could be seen moving in the lighted area to my left, and nothing at all could be seen the other way. The bottom under the tank couldn’t be made out in detail, and in a way I was groping along—though the verb isn’t exactly right, since it implies that you can feel what’s ahead of you. I couldn’t feel anything; I could only note whether my vehicle rolled a little way, a longer way, or not at all whenever another leg was extended. When it didn’t roll at all I had to guess which other legs to try. It would have been a lot easier if I had dared to use enough light of my own to get a decent sight of the bottom, but I wasn’t that silly. If the local population included swimmers, I didn’t have a prayer of knowing when any of them were around; when this mess had started we were thinking of subs and sonar. These I was ready to spot.
The slope was not very regular, as I quickly found. Twice I rolled forward out of control for several yards when I reached a small dip. Once I thought I was stuck for good—I couldn’t go forward, back, or what was presumably downhill toward the light. As a last resort I tried uphill and found that it wasn’t uphill at all; I rolled out of control again into a hollow where I couldn’t see the lighted area except as a vague, diffused glow over the ridge I’d just crossed. Getting out of that hollow used a lot of time and an irritating amount of stored power.
I couldn’t even relieve my feelings with language. The coupling from air through plastic to water, and from water through helmets to gas and human ears, may be pretty bad, but it isn’t zero; and the sound-transmitting properties of cold water make up for a lot of matching deficiencies. I didn’t dare say a word.
Once out of that devil-invented gully I stopped, once more in full sight of the tent roof and tried to take stock.
My power was rather low. There was no way of telling whether I might reach the entrance in three hundred yards or three thousand; the former seemed more likely, since the girl hadn’t taken too long to come back with her help, but then she might have met the men already outside. Nothing was certain enough to give any possible line of action even the dignity of a calculated risk. It wasn’t possible to calculate.
I had to find out more, though. I’d cooled down a little from my original reaction—I could believe what I’d seen, and I realized that others would, too—but the news I had wasn’t as helpful as it was supposed to be to the Board. If a police unit were to do anything but grope around, it should know where to start. A regular entrance would make a logical place. Of course it wasn’t likely that the tent roof would really keep a sub out; but judging by the area the tent enclosed, the chances of breaking through at a strategically useful point would be rather slim.
Maybe the best thing to do would be to throw out the caution policy and turn on my lights. The extra power would be offset by more efficient travel when I could see where I was going and I should stand a better chance of reaching the entrance before my juice failed entirely and automatically let my ballast go. If I were seen, no doubt some of the swimmers would come close enough to give me a really good look, so I might get a better idea of their high-pressure technique before I left.
I’m a cautious man by nature, and thought that one over for quite a while before I bought it. There was plenty against it, of course. Just because all I’d seen was swimmers rather than subs didn’t prove there weren’t any subs. If there were, there would be an excellent chance that I could never get back to the surface—but I’d accepted that risk before starting the trip. I ping-ponged the matter for several minutes. Then I took a good, deep breath on the theory that I might not get many more and turned on one of my spots.
It made a difference, all right. The bottom was mostly rock, as I’d suspected, and was very rough—no wonder I’d had trouble using my legs effectively. Able to watch what I was doing, I resumed travel and, as I’d hoped, made much better speed with much less power drain. It wasn’t exactly easy yet; I was still rolling, and had to change lights as well as legs as I rolled, but the improvement was encouraging.
I could see more motion around me. There was a lot of small life—shrimps and their relatives—that I hadn’t been able to spot before. They got out of my way without being too distracting. There were also plantlike growths, though considering how far they were from the nearest natural light it seemed likely that they were sponges or something of that sort. They neither helped nor hampered the rolling, as far as I could tell.
However, I was paying for the much better short-range vision with a much worse view of distant objects. I might have been surprised quite easily by a group of swimmers, but what actually happened was less predictable. I lost orientation.
Not in the compass-direction sense and not completely. I could still see the lighted area to my left, though not as well as before; my compass still worked, when it happened to be right side up; but my sense of up and down, depending more on my view of a few square yards of ocean bottom than on my semicircular canals, was fooled when some of the bottom ceased to be horizontal.
The change must have been gradual, or I’d have spotted it within the small area I could see well. As it was, I overlooked it completely; suddenly I was on an area of rock sloping much more steeply than any I had traversed up to then. Before I knew it the tank had started a stately roll to the left; after I knew it, leg after leg poked out in that general direction proved useless.
It wasn’t like rolling downhill in a barrel; it was a slow and graceful motion. I could easily have stayed upright inside the tank if I’d chosen to concentrate on that problem instead of on the controls. For all the use I got out of the latter, I might as well have concentrated on comfort. Some of the legs may have slowed me a little, but none of them came close to putting a stop to the journey. I rolled helplessly into the lighted region and out onto the tent fabric. For several long seconds my report-making attention was divided almost equally between up and down.
Above me I could see the lights clearly for the first time. They were ordinary high-pressure, excited-vapor lamps, bigger than I’d ever seen used for general illumination, but otherwise nothing strange. I still couldn’t see what held them in position, since looking up at them was hard on the eyes.
Looking down was harder on the imagination, though mine was getting a bit calloused. I already knew that the fabric was remarkably strong and elastic; I’d seen how it reacted to Pugnoses’s bow, which must have had some pretty sharp corners here and there. I also knew that it was opaque, or at best translucent, in its normal state. I realised that the part now under my tank would be-stretched. But it hadn’t occurred to me that stretching the stuff would make it transparent.
IV
When I stopped moving, however, I could see ordinary sea bottom—rock similar to the stuff I had been rolling across—under me. For a moment I thought something must have stopped me short of the tent roof after all, but glances through several of the ports killed that notion. I was nearly fifty yards out on the thing, sunk into it for just about hal
f of the diameter of the tank. From ports above that level I could see the lights above and the smooth fabric below; from the lower windows I could make out rock and occasional patches of silt on the bottom and a greenish-white, evenly glowing ceiling above—evidently the fabric, lighted from the other side. It was translucent, then; but the part of it stretched around the lower half of the tank offered no interference at all to vision. Some of the legs were extended on this side, and the stuff seemed to have spread in an invisibly thin layer over these as well—they could hardly have punctured it or I wouldn’t have been hanging on the roof. Someone must have done some very fancy work in molecular architecture, I decided—which shows how a wildly wrong set of premises can at times give rise to a correct conclusion.
But why the tent at all? The sea bottom under it looked no different from that above. There was no sign of any human being or artificial structure in the region below. There weren’t even any living beings that I could see, and I certainly looked hard—it occurred to me for a moment that someone might have gone so far with the energy-wasting business as to try growing natural foods with artificial light. The idea at least went along with indifference to ordinary morality about energy; people who’d shine all those kilowatts into the ocean probably wouldn’t boggle at overreaching their fair share of area in order to grow mustard or something like that. The sea bottom was about the only place on Earth where such a trick could be pulled without being caught right away by indignant neighbors, to say nothing of the Board. The only trouble with the theory, other than one’s natural reluctance to believe in such people, was that I couldn’t see anything growing. For that matter, I didn’t know what sort of food plant could be grown under sea water. There were some, no doubt; and if there weren’t natural ones, there is always gene tailoring.
A more immediate question was what to do next. Thirty seconds of trying proved that I could extend and retract my legs until the power cells ran down without moving the tank at all. They just didn’t have anything to push against; the bottom was a little too far down. I tried rolling the thing by shifting my weight. This worked as far as turning the tank over was concerned, but didn’t get me noticeably closer to ‘shore’. It seemed that the only freedom of motion I had left was upward.
This was a little annoying. I had planned to plant a small sonar transponder near the entrance when I found it, as a guide for the police boats. If I dropped it here, it would mean very little and furthermore would be seen lying on the tent fabric by the first person who happened to pass, either above or below. If I’d had the reaction time and foresight of a fictional hero I might have let one go when I realized I was out of control; but I hadn’t, and there was no use moaning about it.
I might wait until they found the tank and just hope for a chance to drop the instrument without anyone’s noticing while they were carting me off, but that seemed to involve a historical record for optimism.
I couldn’t accept the idea of going back to the surface without leaving it, though, even though that and all the other things it would be so nice to get done seemed to be impossible. Even a snake on a tray of oiled ball bearings keeps wriggling.
And so I remained. There was really no point in an early departure anyway. I still had plenty of oxygen, and there was always the hope that I’d get a useful idea before they—whoever ‘they’ were—found me. The hope lasted for nearly six hours.
It wasn’t a girl this time, though it might possibly have been one of the same men. He wore the same sort of swimming outfit to the last detail, as far as I could see. He was swimming straight toward me when I first saw him, above the tent roof as the others had been, slanting out of the darkness from the direction I supposed the entrance must lie. Certainly he had seen me, or rather the tank. I wished I had spotted him earlier—it would be interesting, and might even be useful, to know whether I had been found accidentally by a passing swimmer or by someone deliberately checking the region where the wrecked boat had been found. However, I could be philosophical about not knowing. I watched as he swam overhead.
He should be able to recognize the tank without much trouble. It had a lot of nonstandard equipment fastened outside, but it was basically a regular emergency high-pressure escape tank of the sort you’d find in any large submarine—a sphere of silica fiber and high-stress polymer able to stand the pressure of two miles of sea water. It was light enough to float, ordinarily, but the jury-rigged thing I was in was well ballasted. Besides the legs and their accessory gear there were the lights, the transponders, sundry pieces of sensing equipment, and several slabs of lead so distributed as to keep the center of buoyancy and the geometrical center as close together as practical. The lead made the real difference; I would still float with all the rest.
The swimmer stopped stroking as he glided overhead and drifted, settling slowly toward me. I could see his face now through the helmet—in fact, the helmet itself was barely noticeable; he might almost have been swimming bareheaded. He was no one I could remember ever having seen before in five years, of Board work, but I took good note of the line of his black hair, the set of his eyes, and the squarish outline of the rest of his face so as to be sure of knowing him again if the chance ever came up. Presumably he couldn’t see me; the view ports were small, my inside lights were out, and he showed no sign of the surprise I would have expected him to feel if he knew or guessed that the tank contained a living man.
He came close enough to touch the equipment—so close that I could no longer see everything he was doing. I told myself that it couldn’t be anything very drastic, considering what the tank was built to take, but I’d still have been much happier if I could have seen his hands all the time. He was certainly fooling with things; I could feel the casing quiver occasionally as he pushed something particularly hard.
He drew away again and swam twice more all around the tank, never taking his eyes from it. Then he settled down to the tent roof and pushed his head against it, as though he were trying to swim through.
I didn’t dare shift my weight quickly enough to look through one of the lower ports while he was still in that position, so I couldn’t tell whether his helmet stretched the fabric enough to let him see through—it was, after all, a lot smaller than my tank. I did let myself down very gingerly, so as not to move my container noticeably, but by the time my eyes had reached one of the lower ports he had risen again—at least, I could see nothing against the fabric except his shadow. He seemed to have started swimming away, and I took a chance and straightened up quickly. The shadow had told the truth. He was heading back in the direction from which he had come.
This time I was much more careful with the clock. He was back with another man in just under eight minutes. His companion was carrying either the cylinder that had been used in moving the wreck, or one just like it; the first man was also carrying something, but I couldn’t make out what it was right away. It looked like a rather untidy bundle of rope.
When he stopped above the tank and shook it out, however, it turned out to be a cargo net, which he began to work around the tank. Apparently he had decided on his first inspection that the natural irregularities of his find didn’t offer much hold to a rope. I couldn’t exactly blame him for that conclusion, but I very much wished he hadn’t reached it. I wasn’t sure how strong the net might be, but unless it were grossly defective in manufacture it would hold my ballast slugs. If it were fastened around tank and slugs both, releasing the latter would become a pointless gesture. It was definitely time to go, and I reached for the master ballast release.
Then I had another thought. Dropping the lead would presumably give my presence away, assuming they hadn’t already guessed there was someone inside. That cat was out of the bag, and nothing else I could do would tell them any more. I might as well, therefore, try something else which might keep that net from enfolding me until I was over bare rock again and stood a chance of dropping the transponder effectively. There seemed nothing to lose by it, so I extended all the legs at once
.
Neither of the swimmers was actually hit, but they were very startled. The one with the net had been touching the tank at the time, and may have thought that something he had done was responsible for releasing the springs. At any rate, neither of them seemed to feel that any more haste than before was needed, as they should have done if they’d suspected a man was inside. They simply went about the job of attaching the lifting device as they had to the other wreck; there were plenty of things to fasten lines to now that the legs were out, and it would have been hard or impossible to get the net around the new configuration. That was all to the good.
The technique was the same as before. I assumed the cylinder contained a chemical gas generator, considering the pressure the balloon was expanding against. That was just a fleeting thought, though. It was much more interesting to watch the two swimmers pushing me toward the edge of the roof even before my container had lifted entirely clear of the fabric. Things were certainly looking up; only two people, bare rock coming up—no, don’t be too hasty; maybe they’ll push you right to that entrance you want to find. Wait it out, boy. I pulled my fingers away from the panel, and locked them together for extra safety.
Just as had been done with Pugnose, the tank was moved away from the tent and then along parallel with its edge. The motion was slow—even with a weightless load there was plenty of water to push out of the way—and we were more than fifteen minutes on the trip. I kept watching for some sign of the entrance, expecting a break of some sort in the fabric itself, but that wasn’t the arrangement I finally saw.