I saw another swimmer, quite close, dwindling between me and the light; my second passenger must have dropped off. When would the first go? His light was still shining, but it could hardly do any good now. I could barely see the pit, and surely no one down there could see his little flash.

Evidently he realized this, for after a few more seconds it went out. I expected to see him leave like his fellow, since he could do no more good by sticking, but he wasn’t thinking along those lines. He had different ideas, and one of them from his viewpoint was a very good one. I didn’t like it so much.

The dual-phase stuff they make pressure tanks out of isn’t a metal, and differs widely from any metal in its elastic properties; but like metals, if you hit it, it makes a noise. I didn’t know what my rider started hitting with, but it most certainly made a noise. I, from inside, can vouch for that. A nice, steady, once-a-second tapping resounded from the tank, hurting my ears and doing worse to my plans. He didn’t need his light; any work sub could home in on that noise from miles away if it had even a decent minimum of instrumentation.

And there was no way that I could think of to stop him.

I could try the legs, of course. I did. It was so dark by now, with the light from entrance pit and tent roof alike faded to the barest glimmer, that he may not even have known that I did anything. If he’d been holding on by a leg he may have been disconcerted when I pulled it in and maybe bruised when I popped it out again, but there was no evidence that anything of the sort happened. I ran the legs through their cycle several times without making the slightest change in the rhythm of that tapping.

I tried shifting my weight to make the tank roll over. It worked, but didn’t bother my passenger. Why should it? A swimmer doesn’t care whether he’s right side up or not, and a submarine hitchhiker in total darkness should care even less. I was the only one who was bothered.

But why was this character alive, conscious and active? We’d risen more than a thousand feet now, through a pressure difference that should have popped his suit if it were really sealed as tightly as I had judged. If it weren’t, and if he were valving off gas to keep his lung volume down, he was going to be in trouble when he descended again; and in any case, volume or no volume troubles, whether he was breathing helium or anything else, he should by now be completely helpless with embolisms.

The simple sad fact, independent of what should be, was that he was still going strong, and I had no way of getting rid of him.

Nothing like this had been foreseen by the Board geniuses who had worked out this mission. There was not the slightest doubt that some sort of sub was going to be along shortly to pick me up — no other notion was sane, in view of the fact that this fellow had been fit to stick with me. There were always insane notions to consider, of course; maybe he had decided to sacrifice his life to make sure I didn’t get back to the surface, but even that assumed the coming of something. Maybe a torpedo, but something. Personally I doubted the sacrifice idea. Lots of people will, for a cause they consider important enough, but I’ve never met a lawbreaker who acted that way. Especially I’ve never seen an energy waster who would; selfishness is the key word with those lads — keep the eye out for Number One.

But never mind the psychology; what’s to be done? The guy may be a moving corpse, but he’s still there broadcasting. Why didn’t I come down in a work sub? Skip that question; it’s a waste of good thinking time. How can I make him get off, or at least stop making noise?

Badly phrased question. I can’t make him do anything. He’s outside, and I’m inside, and with his pressure difference never the twain shall meet. Then, how can I persuade him to leave or shut up? Until I start communicating, I can’t persuade him either. Obvious.

I put on my lights, both inside and out. That at least caught the fellow’s attention; the tapping stopped for a moment. Then it resumed, but less regularly, and I caught glimpse’s of him as he worked his way to a place which would let him see through one of the ports. I pulled my own face far enough back from it so that he could see me clearly, and for a few seconds we just looked at each other. The tapping stopped again.

It was the same man who had found the tank. I’m not a mind reader, but I felt pretty sure from his expression that he had only just realized there was anyone inside and that the discovery bothered as well as surprised him. He resumed his banging on the tank, in a much more irregular pattern. After a few seconds I realized that he must be sending some sort of code, though I couldn’t read it.

I tried to explain my gestures that the racket was hurting my ears, but all he did was shrug. If he cared at all about my comfort, it certainly wasn’t at the top of his priority list. He finished his code message at last and resumed the regular tapping. He didn’t seem angry — didn’t scowl, or shake a fist at me, or anything of that sort, but he didn’t look as though he considered me a long-lost friend, either. I could see his face clearly and without distortion through the helmet, but I could see no sign of real interest in his expression. I spent some time trying to get him to respond to my gestures, but he paid no attention. I thought of writing a note that he could read through the port, though I couldn’t guess what languages he might know, and I managed to find some scraps of paper in one of my pockets; but I could find nothing to write with, and that idea collapsed. I finally gave up and turned my lights off again. There was no use in helping him guide the sub to us.

I couldn’t think of any more practical plans, and my mind wandered back to the question of how the fellow lived. We had risen several hundred more feet during the time the lights were on, and his suit hadn’t emitted a single bubble. I was beginning to wonder whether it really was an ambient-pressure unit. It was hard to see how anything so thin, and especially so flexible, could possibly be pressure armor; on the other hand, the peculiarities of the tent roof indicated that someone had been making progress in molecular architecture. I was in no position to say such armor was impossible, but I wished I could make at least a vague guess as to how it was done.

I can feel a little silly about it now, of course. I’d had the man in full sight, well lighted, only a few feet away from me for fully five minutes, and I missed the key fact — not in something I saw but in something I didn’t see. At least, I’m not alone in my folly.

The tapping kept up. It wasn’t really loud enough to be painful, but it was annoying, Chinese water torture style. It may have been equally so to the. fellow outside who was doing it, and I got a little consolation out of the thought that at least he was having to work at it. I got a little more out of the realization that as long as he did keep it up the help he was calling hadn’t arrived yet.

Two thousand feet was less than halfway to the surface, though it was an unbelievable pressure change for my hitchhiker. It wasn’t very much comfort to me to know that I’d put that much water under me; even twice as much wouldn’t be much help. It wasn’t as though there’d be a police squadron standing by to pick me up, or even a single boat. The tank had only the normal automatic transmitters for calling help, and they wouldn’t even start to function until I reached the surface — which I was unlikely to do. There probably was a Board vessel within a few miles, since the plan didn’t include my navigating the open halves of the tank to Easter Island when I got back to the surface, but that would do me no immediate good. The storm would probably still be going on, and they wouldn’t be able to see me at fifty yards. If they did, they probably couldn’t do anything about it unless there were more specialized salvage gear aboard than seemed likely. Even a minor ocean storm is quite a disturbance, and one doesn’t pick a pressure tank bobbing around on its waves casually out of the water.-