by Hal Clement
The tank in tow was struck several times, forcing travel to cease while it was examined carefully by servobugs, but so far damage had been confined to small dents. The one strike on Annie had caused no damage at all, possibly because the traction problem had forced her to be grown with much extra weight.
They had seen and avoided the common puddles of unknown makeup, but as the sky ahead grew bright these became larger areas and more frequent. Annie avoided them, though the returning Jellyseal apparently had not. The white crust on her tracks and lower body had turned out to be mostly cryolite, sodium aluminum fluoride, regarded by Greenland natives on Earth as a peculiar form of ice because it would only melt in the flame of a blubber lamp.
It was now pretty obvious who, or what, had driven the tanker homeward. Dominic had already compared the fate of the driver with that of his wife, but had not spoken about it to anyone. For one thing, a lot of the how remained to be worked out. The tangle of apparent vegetation might, after all, have been some sort of remote control system; this world’s plants did emit and receive microwaves. Maybe no intelligent being had been on board, at that. This could all tie in with the natives’ immediate spotting of, and beaming signals to, the satellites when these had gone into operation months before. The graphite microtubes in Halfbaked tissue often circulated metal ions and could serve as antennae, among many, many less obvious things. It seemed more and more necessary, and more and more easy to believe, that the real life was at the source of the signals. And maybe one of the girls . . .
No, Don’t think of that. Whatever had happened to them had happened very quickly—one could believe that, at least—and pretty certainly to both of them at once.
But it looked as though veering around lakes might not be really necessary, since they were going Hotnorth and anything that froze on the vehicles now should melt off again shortly. Nic did suggest this. Pam vetoed the idea at once.
“How do we know how deep these things may be?”
“Do we need to? We’d float. We’re only twice as dense as water.”
“That wouldn’t matter to us, but could we drive, towing like this?” Nic had no answer, and they continued to stay on solid, if sometimes shaky, ground. Neither of the other men had taken part in the debate.
Just as they glimpsed the upper limb of the sun, a new sort of adventure eased the boredom. They were threading their way through a stand which looked much like the “Saguaro” patches Nic and Erni had found earlier. The growths were not always far enough apart for the tank, and much as they disliked it, there was sometimes no alternative to hitting and bending pairs of these, or sometimes breaking them completely. They were leaving a clear trail, not that this was their main worry.
Nic was glad afterward, though he was far too busy otherwise to think of it at the moment, that none of his attempted weather predictions was pending. With no warning at all a far stronger wind blast than any of them had experienced so far made itself felt to the driver. Organ-pipes bent and snapped in all directions.
And, though there had been no lightning, burst into flame. For minutes they drove through the enveloping blaze, making no effort to avoid anything. The mere fact that there was no free oxygen outside meant nothing; it had not occurred to anyone to consider what the paraffin would do in unlimited supplies of this atmosphere. There was no free fluorine to speak of, but the variety of fluorine compounds actually present offered far more possibilities than any of them had time to consider. Pam joined her husband at the driving controls; Erni, with remarkable self-discipline, beamed a running report of what was happening for any satellites in position to relay to Nest; Nic deployed one of the more versatile servobugs and drove it beside them, ranging back and forth along the tank and looking carefully for any signs of rupture. After a few seconds Pam, deciding her husband needed no help—he was not attempting to dodge anything—took out another bug and covered the other side.
They were out of the stand, and out of the fire, and presumably out of danger after three or four anxious minutes. The wind now came strongly from ahead; Nic judged that the fire had set up a strong updraft which was bringing in air from all directions. Erni, with no wager going, didn’t bother to disagree, and neither of the others found the suggestion unreasonable.
A few hundred meters from the nearest flames Annie and Candlegrease were stopped and all four of the crew made a slow and minute inspection of tug and tow using the bugs. There was little worry about their own vehicle; they would have been aware of serious damage within seconds of incurring it. A slow leak in the tank, however, was another matter. It was assumed that the natives were equipped to unload the paraffin at their end; they had been told as clearly as possible what it was, and would presumably be ready to keep any of the precious hydrogen from escaping. Also, they had made no complaint about the first delivery.
But no one had tried to find out what the paraffin itself would do to local life. It seemed very likely that hydrogen compounds would be about as helpful to Halfbaked’s organisms as fluorine ones in comparable concentration would be to Terrestrial tissues. Also, many paraffin components were high enough in molecular weight to sink in the local atmosphere; they would be mixed and diluted quickly by wind, of course, but wouldn’t rise on their own.
The travelers reminded Ben of this, and asked for suggestions. What if they did find a leak, even a small one? Should they come back, at least to Hotlatitudes where the paraffin would freeze again?
“I’ll have to ask around,” was all the coordinator could say after some seconds of thought. “Get along with your inspection, and let us know. For now, we’ll assume the worst.”
“What would that be, to you?” asked Erni.
“That you’re leaking so badly there’s no way of getting any of your load to where it’s supposed to be delivered. That would make the decision easy, but I hope it isn’t true.”
So did the crew, but they were still careful.
There were half a dozen patches of liquid near and under the tank, but there were two similar ones near the tug, and several more within a few tens of meters. There seemed no reason to suppose they were hydrocarbons, since they seemed neither to be evaporating nor reacting with the now quite hot air, but they were watched carefully for several minutes, especially those under the tank. At Nic’s suggestion, they moved the vehicles a hundred meters to an area where no puddles could be seen, and waited for more minutes.
Nothing dripped. No puddles formed. Nothing seemed to be leaking. This was reported to Cloud. He had had time think, or someone had, and his answer was, “Check every bit of the tank you can get an eye close to for the tiniest cracks, leaking or not, which may show. Remember the one in Jelly.”
“What one in Jelly?” asked two voices at once.
“Didn’t I tell you? No, come to think of it, that just led to more questions, some of them still not answered. We think we know what happened, now. The refrigerators meant to keep the paraffin from boiling when the surroundings got really hot did a good job, but when the liquid was drained, we suppose by the customers, the tank naturally filled with local air. Some of this, maybe sulfur trioxide, formed frost on the coils and insulated them, so air at its regular temperature—eight or nine hundred Kelvins or more, depending on the local weather—swept in and hit the rear bulkhead of the cockpit. This was too thick, it turned out.”
“Too thick?” There were more than two voices this time.
“Too thick. A thin glass will handle hot washing fluid better than a thick one. The body composition of the vehicles is as strong as we could make it, but it’s also a very poor heat conductor, as intended. It bent in toward the cockpit just a little under the pressure, and that added to thermal shock to start a U-shaped crack in the rear bulkhead from floor to floor, and straight along the floor, framing about ten square meters. The area was pushed into the cockpit momentarily by the atmospheric pressure, far enough to open a gap maybe one or two centimeters wide all around. The support water, or enough of it, boiled almost i
nstantly, the windows blew out, and the steam pressure slammed the flap back where it had come from so tightly the crack was practically invisible.”
“And you never told us? Why not?” asked Pam.
“Well, it couldn’t happen to you. Your living space isn’t even in the same vehicle with the cargo. One point for the towing idea.”
“And several points minus for keeping us in the dark!”
“We’ll check for cracks,” added Dominic, as steadily as he could. They all turned their attentions back to the bugs.
The fire had almost completely died out. So had the wind from Hotnorth. Dominic, glancing away from his work occasionally, saw that the pillar of smoke was sheared cleanly at, he judged, nearly a kilometer above, with the higher part whipping back toward Hotsouth. It was high enough to glow for some distance in the sunlight against an unusually dark and cloud-free sky. He was tempted to try another weather guess, but firmly turned his attention back to Candlegrease’s body. So cracks could be really hard to see . . .
Hard, or impossible. None were found, but no one could be quite certain. Absence of evidence is not—
They drove on into heat and sunlight, more silently than before, with a bug following on either side, its operator constantly scanning the tank. More words were spoken in the next few hours by Senatsu with her guidance information than by all four of the tug crew together.
No one was exactly in a panic, of course, but everyone had enough sense to be uneasy. Erni and Nic were more relaxed than the Treeferns now. At least they seemed to be.
“Open ground for about thirty kilos.”
Ninety minutes of silence.
“What looks like a compression fold across your path ten kilos ahead. Two possible passes. The wider is four kilos to your right. Turn twenty-two degrees right to thirty-seven.”
The planet’s magnetic field was too distorted to provide reliable direction, but enough of the sun was now in sight to indicate Hotnorth—and make driving into it uncomfortable. The new heading was a relief.
The wider pass had walls high enough for the left one to provide shade for nearly a hundred kilometers, a distance which did not lift the star’s disc perceptibly. The valley was not a recent feature; the walls on both sides were greatly collapsed and eroded. Had it been much narrower the travelers would have had a problem threading their way among the fallen fragments.
“Lake eighteen kilometers ahead. Stay close to it on its left.” When they reached the lake, there was not very much rock-free space to the left of the liquid, but there was presumably even less on the other side; the drivers trusted Senatsu. She herself was developing more confidence as reports from the tug kept filling out her interpretations of the satellite radar.
She hadn’t spotted the vegetation which grew densely along the shore, but this gave no real trouble. Erni and Nic thought of die fire now far behind, but there was no sudden downdraft this time. There was, as usual, lightning.
“It could happen,” Dominic remarked. “The right wall is pretty high, and wind flowing over it would drop sharply and heat up by adiabatic compression—”
“How much?”
It was Akmet who asked this time, but Nic declined to bet. Erni wondered whether his friend was actually learning, or simply didn’t want intruders in their friendly game. He said nothing; he was driving. Bet or no, there was no fire, and eventually the Hotnorth end of the lake came in sight.
“Head right along the shore.”
Erni started to obey before realizing it was not Senatsu’s voice. This was not too unusual; the Yoshihashis shared the muscular fitness supplied by constantly fighting water’s inertia, but even they had to sleep sometimes.
“Who’s on?” Erni asked, before realizing that the voice wasn’t human either. The answer was unexpected.
“What?” This was Senatsu, recognizable even through the biological static, now familiar enough to be tuned out fairly well by the human nervous system.
“Who just told me to head right?”
“No one. You’re in fine shape.”
“You didn’t send the message? Or hear it?”
“Neither. Repeat it, please.”
Icewall did so.
“That did not come from here, or through satellite relay in either direction. Is it a native voice?”
“Turn right. You do not turn right.”
Pam was quickest on the uptake, and was first at the communicator. “Why should we turn right?”
“The symbol ‘we’ is unclear. Turn right for safety and information.”
Erni had done a quick-stop by now.
“Sen, did you hear that?”
“I heard static only, none of it either unusual or structured.”
Treefern glanced at her husband, who nodded. His smile was of course invisible. Pam nodded back.
“Sen, this is what we heard.” She quoted. “Now, repeat that back to us, please. As exactly as your voice will let you, and emphatically word for word.”
Senatsu obeyed, mystified but guessing this was no time for argument or question.
The message promptly came again, in the new voice, and the observer gasped audibly.
“I did hear that! It came through the link.”
“I thought it might. They’re not stupid, and certainly not slow. Erni, fire up and do what they say—but keep your driving eyes peeled!”
“For what?”
“How should I know? Anything. What do you usually watch for?”
Icewall drove without answering. It had started to rain, unheralded by Yucca, and Pam thought of a possibly useful question for their new guide. “How far?”
“Twenty-two point one kilometers.”
“Sen, if you heard that, try to see what’s that far ahead.”
“Sorry. I heard it, but radar isn’t getting through just now.”
“Comm frequencies are.”
“True. They’re not very good for imaging, but I’ll do what I can. Stand by.”
The rain grew heavier, whatever it might be composed of, and Erni slowed sharply. The voice promptly came again.
“Why stop.” There was no question inflection.
Pam answered slowly, with measured and carefully chosen words. “Not stopping. Slowing. Rain. Bad measuring.”
“Rain. Bad measuring,” was the acknowledgment. After a pause, “No rain. Eight kilometers. Not slow.”
“Eight kilometers,” answered the woman. “Sen, you heard that? Can you see what’s eight kilos—kilometers—ahead?” There were many listeners by now. Most could guess why Pam had corrected to the full length of the distance label. They also wondered which form the unknown guide would use the next time distance was mentioned.
Tricia Feather’s voice came through to the tug.
“Much more of this and the translation computer won’t need my help! Willi, can you use a math assistant?”
None of the travelers paid attention to this. All were looking eagerly ahead for the predicted break in the rain. Not even Nic tried to second-guess the native.
The really interesting item, they agreed later, was that their informant had allowed not only for their own speed in his, her, or its prediction. The rain clouds had been traveling much faster than tanker and tug, but the eight kilometers was still right. Dominic bowed internally to superior knowledge and vowed to himself, as he had several times before, that Erni would get no more of his cash. Prediction was evidently possible, but not for a mere human being.
Or maybe he could set up some sort of private channel with the natives, and get some of his money back . . .
Neither he nor anyone else was particularly surprised at the sudden improvement in communication, though there was plenty of joy. The natives had been known to exist, had been known to be intelligent, and information supplies do build on themselves and grow exponentially. Maybe Erni’s question about water could be answered soon . . .
“Look up!” Akmet cried suddenly. All except Erni obeyed; he chose to continue driving.
There were scarcely any clouds now, though a number of the blowing black objects still fluttered and swirled above and beside them. One, rather larger than the rest, was dipping, swerving, and wavering in much the same way, but was larger and had a more definite shape.
The tug drivers represented three different colony planets, but all had seen dandelions, which are almost as ubiquitous as sodium and human beings. The object looked like a vastly magnified bit of dandelion fluff. It had a shaft about two meters long, topped by a halo of wind-catching fuzz of about the same diameter, and with a grapefruit-sized blob at its lower end. It must have been incredibly light to be wind-supported in this gravity.
It was moving almost as randomly as the other jetsam, but not quite. The wind-hold at its top varied constantly in shape and size. All the watchers soon realized that it was controlling how much of its motion was due to wind and how much to gravity. Sometimes it lifted sharply, sometimes slowly or not at all; it blew horizontally now one way and now another, but most often and farthest the way Erni was sending the tug. He had speeded up when the rain had stopped, but now he slowed again to stay near the object.
“Go. Travel. Not slow.”
“We want to observe,” Pam transmitted.
“What?” asked Tricia from her distant listening post. Pam gestured to her husband, who described briefly what was happening.
The response was still terse, but comprehensible. “Observe better forward. Not slow. Go.”
“Let’s take its word for it. Go ahead, Erni. It wants to lead us to something, and this thing doesn’t seem to be it.”
Icewall shrugged, refraining from comment about “somethings” on this part of the world, and Candlegrease left the airborne object behind in moments. There were presumably fourteen kilometers to go, and the going was fairly straight.
It was a less impressive prediction this time; the target was motionless.
If this was the target. A branch tangle some fifty meters across and up to eight or ten high, resembling the filling of Jellyseal’s cockpit, was spread at the edge of the lake, separated from the liquid by a meter-high ridge of soil which might have been made by a dozer—or shovels. The ridge—or dam?—ran straight along the lakefront for three dozen meters or so, with each end bending away from the liquid to enclose partially the slowly writhing tangle.
