Chapter Six

I knew what had happened when the regular tapping suddenly changed once more to the complex code, but it took me another half minute to spot the approaching light. I didn't have a very wide angle of view from any one of the ports.

All I could see at first was the light, a solitary spark on a space-dark background, but there could be no doubt what it was. It was just a little below us, well to one side. Its bearing changed as it grew brighter.

Apparently it was approaching on a spiral course, holding the sound of the tapping at a constant angle off its bow to let the pilot keep a constant idea of his distance from the source.

Even when it was close I had trouble making it out, for its main spotlight was turned straight on the tank and there was too little diffused radiance to show anything close to it. This apparently bothered my passenger, too, for there was another burst of code tapping as the sub halted thirty yards away, and the light went out. In its place a dozen smaller beams illuminated the whole area, none of them shining directly our way; so I could see the newcomer fairly well.

It was not exactly like any sub I'd seen before, but was similar enough to some of them to give my eyes a handle. It was small, either one or two men, not built for speed, and well equipped with manipulation gear on the outside — regular arm and hand extensions, grapples, bits, probes, and what looked like a water-jet digger. One of my hopes died quickly; there had been a chance that a small sub would not have enough negative buoyancy to drag the tank back down, but this fellow had big, fat lift chambers and must have ballast to match. It was evidently a tug, among other things. If it could get hold of me, it could pull me down, all right; and it was hard to see how it could be kept from getting that hold. All I had to fend it off were the legs.

I wasn't sure how effective these could be, but I kept my fingers at the panel resolved not to miss anything that looked like a good chance. At least, now that some sort of action was in the offing, I wasn't dithering as I had been during the minutes before the sub came in sight.

The pilot's first method was to drift above me and settle down. He must have had a strong streak of showoff in him, since it was hard to imagine a less efficient means of sinking a round object. I thought he'd have his troubles, but my passenger didn't seem upset, and I have to admit the character knew his boat handling. The swimmer waved him into position, putting me under the sub's center of buoyancy, and he made contact. My pressure gauge promptly showed that the upward motion had been reversed.

I waited a few seconds in the hope that my hitchhiker would go inside the sub, but he made no motion to, and I finally had to let him see my technique. This was simple enough - simpler than rolling along the sea bottom, since the surface above me was much smoother. Also, I didn't have to go so far to accomplish something; a very small shift away from his center of gravity gave my tank's lift a torque that was too much either for his reaction time or his control jets. Since he had enough weight in his tanks to overcome my own lift, he flipped over, and I was on my way up again.

Unfortunately, as I promptly learned, Lester the Limpet was still with me. His tapping started up within seconds of the time I got out from under. His friend evidently took a while to get his machine back into trim — I could understand that; tumbling, with a couple of tons of surplus negative buoyancy thrown in, is a problem for any sub — but he was back all too soon. He was no longer in a mood to show off; he bored straight in, with a grapple extended.

I turned on my outside lights, partly to make things harder for him and partly so that I could see better myself. This was going to be tricky for both of us; he had to find something the mechanical hand could grip, and I had to shift my own body weight so as to turn the tank enough to bring a leg into line for what I had in mind. It was just as well I'd gotten my recent practice on the bottom. At least I knew to a hair where each leg went out, relative to the positions of the ports.

I took him by surprise the first time. He hadn't considered all the possibilities of those legs - maybe he didn't even know how many I could use, though they were visible enough from the outside. He matched my upward drift very nicely, though I was able to hamper him a little bit by shifting my weight and changing the frontal presentation of the slightly irregular tank. With relative vertical motion practically zero, he came in slowly with the mechanical hand reaching for some projection or other — I couldn't tell what he had in mind. I rolled just a little to get a leg in line with the grapple, and when the latter was about two feet from contact I snapped the leg out.

The spring was strong. Remember, it was built to prop the tank in position on a slope even when the ballast was still attached. The engineers who built it could tell you how many pounds of shove it gave. I can't, but I could feel it. The sub and tank were pushed neatly away from each other. The line of thrust was not exactly through the center of my shell, and I got quite a bit of spin out of it. The sub didn't.

Either the push was better centered on him or he was quicker this time with his control jets.

He was a stubborn character. He came back and tried the same thing again, after my spin had stopped. I was able to repeat, with about the same results. Konrad the Chiton was still with me, though, and he had my technique figured out by this time. He moved a little away from me to free his hands for signaling, waved them for about ten seconds in a complicated pattern that meant nothing to me, and then came back and took hold of the tank once more.

The sub made another approach, similar to the preceding two, and I tried to line up for another kick.

My friend, however, had different ideas. He was much farther from the center than I was, and could exert much more torque. He could also see where the legs were, and when I shifted my weight to line up the proper one with the approaching grapple he interfered. He was too smart to fight me directly, though he probably could have managed it; instead, he let me get moving and then supplied an extra shove to one side so that I either overshot or missed the right position. I made three attempts to line up as the hand was coming in and finally gave the kick a little out of line when the sub was about to make contact. The leg grazed the side of the handler and put a little spin on the tank, but didn't hit anything solid enough to push us apart. Worse, it gave the sub operator a chance to grab the leg itself. This he seemed to feel was a better hold than whatever he had planned on; he clamped on tightly and began to cut buoyancy once more.

This proved to be a mistake, though it didn't help me as much as it might have. The leg wasn't strong enough to hold the tank down. It parted, and once more the sub disappeared below me. I cut my lights promptly, hoping that my passenger had lost his hold with the jerk. Maybe he did, but if so he wasn't far enough away to lose track of me. In a few seconds the tapping resumed, and in a few more the lights of the sub were close enough to make my blackout an idle gesture. I turned mine back on again so that I could see to resume the sparring match.

Now he got the idea of making his approach toward the spot where the leg had been lost, so that I'd have to turn further to bring another into line. My swimming friend was co-operating nobly, and for a little while I was afraid they had me. The sub operator was too smart to try for a leg again, but he managed to keep out of the way of several kicks I gave out. He got in, made what should have been a successful grab at something on my outer surface, but was hurried and missed. He had to back up for another try . . . and I had time to get another idea into operation.

I knew where the swimmer was. I could see enough of him to tell not only that but to guess which way he'd be pushing next time. I began to put a spin on the tank with him at one pole so that he wouldn't notice it quite so quickly. This worked, though I didn't get a really rapid rotation — I couldn't, of course, with such poor torque; but with the tank's weight I had enough for what I wanted. One of my strong points in basic physics, ages ago in school, was mechanics. I couldn't handle the present problem quantitatively because I didn't know either my angular speed or the tank's moment of inertia, but I hit the qualitative answer on the button. As the grapple approached again I shifted my weight to start the tank processing. Billy Barnacle tried his usual stunt of pushing me sideways and sent the leg right through the point I wanted. Either he'd forgotten what they'd taught him about gyroscopes or he was getting tired. I hit the grapple dead center with my kick, and we were apart again. If I'd been driving that sub, I'd have been getting tired of the whole business by now.

Apparently he was more patient than I. He was back again all too soon.

I had gained maybe three or four hundred feet with each pass of our duel. I had an uneasy feeling that I was going to run out of tricks before those increments added up to the total distance to the surface.

Certainly if he had the patience to keep repeating the same technique, he'd soon run me dry.

He didn't, though. He seemed to have decided that the grapple wasn't quite the right tool after all. When he came back next time he did his usual speed-matching some distance above me, instead of level. A small light flickered, apparently in code, and my pressure-proof friend let go of the tank and swam up to the sub. He was back in a moment, trailing a line behind him.

Apparently it had been decided that human hands were more versatile than mechanical ones.

At first I wasn't worried. There was nothing on the outside of the tank except the legs which would really lend itself to the attachment of a rope, and it had already been demonstrated that the legs weren't strong enough. Hours before, on the bottom - no, come to think of it, it was much less than one hour -

my pal had felt the need of a cargo net to wrap around the sphere. If he didn't have such a net here, all should be well.

He did, unfortunately. It was bigger and heavier than the one they had had on the bottom, which was probably why he wasn't swimming with it. When he got back just above the tank he began hauling on his line, and the net emerged from one of the sub's service ports. He pulled it to him and began to spread it out so that my tank would float up into it. He failed the first time through no doing of mine; he simply didn't get his net deployed in time. I ran into it while it was still only partly open. It had more of its weight on one side of me than on the other, so I automatically rolled out from under it and kept on rising. I didn't have to move a finger. The sub was also rising, of course, so the net trailed downward to the end of its line and folded itself together. The boy in the sub had to reel in mechanically while the swimmer held onto me, before they could go through it all again.

That was another few hundred feet gained.

The next time they spread the net much farther above me. Once open it was even less maneuverable than the tank, and by a little judicious rolling to make the outer irregularities affect my direction of ascent I managed to get far enough from its center to roll out the same way as before. What that team needed was two more swimmers, I decided.

It turned out that one more was enough. They reeled in the net again, lifted the sub a distance, adjusted its buoyancy so that it rose a little more slowly than I did, and then the operator came out to join the swimmer. Each took a corner of the net and with the boat for the third corner formed a wide triangle which they were able to keep centered over me. I tried to work toward the sub, which seemed to be unoccupied and wouldn't back up to keep the net spread. It didn't work. The men moved just a little in the same direction, letting the net sag toward me.

The next thing I knew it was draped around me, and I couldn't tell which way to roll even if I had been able to start rolling. The swimmers came in from their corners and began tying it together at the bottom.

If they finished, I was done. I watched them as well as I could, trying to spot where there was an edge

— anything to tell me that there was more weight of net on one side of me than the other. I spotted what I thought was a chance to interrupt the work while I got a better look, and I'm afraid I took it.

One of the men was next to the tank and a little below it, pulling a section of net closer. Maybe it was the sub operator — the light was good, but I didn't take time to check —and he wasn't as familiar with the leg arrangement as his companion. Anyway, he was in the way of one of them, and I let him have it.

My intention, if I had one — I really didn't take time to think — was to knock him out of the way so I'd have a chance to roll out of the net. I certainly didn't mean to do him serious or permanent damage. The disk at the end of the leg, though, caught him on the right side and could hardly have helped breaking some ribs. It kicked him away like a shark butted by a dolphin. The line he was holding practically flew out of his right hand, and a tool whose nature I couldn't make out fell from his left. He began to sink out of sight.

The other swimmer was onto him before he'd left the reach of the lights. He was evidently out cold; his body was completely limp as his friend towed him up toward the sub. I didn't watch too closely, partly because I was trying to roll myself out of the net and partly because I regretted what I'd done.

I made little progress with the rolling. They'd gotten some knots into the system already, and it looked as though I were there to stay. I managed to make a half turn, getting what had been the tank's bottom when I was caught swung up to the top, but it didn't do me a bit of good. The meshes wound around the tank even more tightly during the turn.

I was a little above the sub by that time - as I said, they'd trimmed it to rise a little more slowly than the tank - and the tension on the line connecting the net with the boat was swinging me directly over the latter. It was also tipping the sub, I noticed, since the line wasn't attached anywhere near the latter's center of gravity. I watched, helpless but hopeful, to see whether the single rope was strong enough to drag me down when they really put weight on the boat.

I didn't find out. The uninjured man towed his companion to the little vessel, opened its main hatch, and after some trouble got him inside. Up to that point we'd still been raising. Now it appeared that the sub was putting on more weight, for the line tightened and my pressure gauge reversed its direction once more. However, the sub, which had leveled off after the men got on board, now went down badly by the stern. Evidently the off-center lift through the net line was more than could be countered by shunting ballast, at least if enough total weight was in the tanks to maintain a descent. Apparently there was a higher priority attached to bringing me back than to keeping the boat level. I watched, with my fingers crossed, hoping the line would give.

It didn't, but someone's patience did. Maybe the swimmer I had hit was seriously injured, though I hoped not; but whatever the cause, whoever was now running the sub decided that speed was of prime importance.

He suddenly cast off rope, net, and all, and disappeared in a few seconds. I was alone at last, bound once more for the surface. It was almost an anticlimax.

It was also quite a letdown. The dogfight, if you could call it that, had lasted only ten or fifteen minutes in all and certainly hadn't involved me in much physical labor, but I felt as though I'd just done ten rounds with someone a couple of classes above my weight.

Now I was safe. There wasn't a prayer of their finding me again without sonar, with no one hanging outside to broadcast sound waves from my own hull, and with my lights out — I hastily turned them out as that thought crossed my mind. I had less than two thousand feet to go — not much over ten minutes, unless the drag of the net and line made too much difference. I watched the gauges for a while and decided that they didn't, and for the first time since I'd left the surface I fell asleep.