by Hal Clement
The Box had been making no speed readings on the image. Hugh had asked it to supply an enlarged view of the region around the craft but given no instructions about scale, so he could not tell how fast the machine was going, and there were of course limits to the resolving power of sonar that even The Box could not overcome. There was no way for it to show him the smaller plankton, and even large seaweed masses and animals were merely featureless dots in the hologram.
But dots motionless with respect to each other were probably seaweed, and they were drifting past Janice’s vessel surprisingly quickly . . .
“Box! Doppler the sub!”
Since The Box had merely been correcting for doppler without displaying it, the visible response was immediate.
“She shouldn’t be going that fast! All four thrusters must be wide open! Jan! Jan! What’s wrong? Are you all right?”
There was no immediate answer, but Hugh was not completely out of his mind. He could still allow for message delay.
Code finally sounded from The Box’s relay unit.
“Thrust control. Shaking loose. May abandon. Watch.”
With clenched fists and bitten lips, Hugh watched. He called the Cephallonians, and The Box without instructions set up a larger display in their tank so that they could see as well, but no more was said for the moment. Instructions were useless; Janice would know what she was doing, what she had to do, and when it had to be done seconds before any of the others could tell. It would be nice to know what had gone wrong with the drivers, but asking her now would be somewhere between futile and dangerous.
They watched while the eight-meter-long framework drove into an upwelling current of nearly four meters a second at roughly three times that speed. The display showed a small object separate from the submarine and sink for twelve or fifteen meters, halt with a jerk with respect to the craft and remain matched to its vertical speed. Hugh sighed in relief, but ground out some words between his teeth.
“For sense’s sake, dear idiot, positive buoyancy!”
Thrasher was almost as upset, but spoke more sensibly. “I don’t think that’s Jan, Hugh. More likely one of the thrusters, judging by weight, held by part of the original lashing somewhere ahead of the center of buoyancy. Look at the sub!”
The framework was nosing downward, and starting to move in the same direction.
“Cut it loose, Jan!” cried one of the Cephallonians. “You’ll never get the bow up with that thing hanging from it!”
Even Hugh realized that his wife’s weight could never have produced that much effect, tricky as the sub’s balance had proved to be and regardless of any buoyancy she might have adjusted in her suit, and decided the swimmers were probably right. This did little to make him feel better, however.
The Cephallonians were loading oxygen tanks; they hardly ever removed their suits—the ammonia of Habranha’s ocean irritated their skins. Even here at the warm pole, where the stuff was least soluble and occurred mostly in the air, forcing their Erthumoi companions to wear breathing masks even out of the water, the swimmers needed protection. Near the Solid Ocean, as the natives called the darkside glacier, where Erthumoi could breathe unprotected for minutes with little discomfort if they were careful about hyperventilation on the extra oxygen, Cephallonians found the water much worse. Now, therefore, they were ready for the rescue in moments. There was no need for talk; they knew The Box would guide them and provide information updates, and they didn’t need requests or instructions from Hugh. They plunged into the waves from the open stern of their tank, and the Erthuma watched their departing images in The Box’s main display.
If that dangling object were a loose thruster and not Janice herself, why didn’t she cut it loose? With the sub now traveling downward, why didn’t she cut herself loose if that were her own image or get out if it weren’t? Clearly the craft was out of control. Granted it represented a lot of work and, for the group, some irreplaceable equipment, but Janice wasn’t stupid. As long as she were conscious—if she were—
Hugh Cedar clenched his fists and watched the special display even more closely, wondering whether the swimmers would reach the foundering sub before it got below The Box’s range of clear perception. He cursed luridly every few seconds as the artificial mind changed its electronic opinion and modified shape or position of some part of the picture to fit new data. He could have argued with it, since the Cephallonians were too far away to be bothered by his treating a machine as a fellow being, but no number of words would have been any improvement in detail on the image, and would certainly have been far slower.
Why was she staying with the sub? Had something knocked her out? Had motion sickness overcome her, and parts of that huge last meal blocked her air passage? Was she still inside the vessel, or was that, in spite of logic, her armor hanging meters below it? He kept reminding himself firmly that she should float; even if the suit leaked diving fluid, any freed volume would be replaced from emergency oxygen tanks and the overall density reduced. The dangling blob must be a loose thruster, as Thrasher had insisted.
But why wasn’t she doing something about it? And when were those jellyfish going to get to her? He spoke to The Box for the first time in-minutes.
“How far do they have to go, and what’s the closing rate?”
“Six point seven one kilometers equivalent distance. I am guiding them on a path which allows for all current deflections. They should reach the sub in just over eight minutes, which I assume is what you really wanted to know. The meeting should occur well above the depth limit of the Cephallonians, so you need not worry.”
“I hadn’t thought of worrying about that. Thanks. Just how sure are you whether that hanging thing is a thruster, as Thrasher said, or Jan herself?”
“It is much too dense to be human armor, even occupied. That interpretation had not occurred to me. If I had known you were concerned—”
“Then she’s still inside the sub?”
“I would certainly have observed her separation.”
“Then what’s the silly darling doing? Why is she heading down? I know she can take any pressure this world can give, loaded up with diving fluid, but a few more kilometers and she’ll be out of reach of any possible help!”
“Are you being rhetorical, or do you want me to ask her?”
Hugh hesitated only an instant. “Rhetorical, I guess. She could be busy enough for interruption to be dangerous. She must know we’re watching and worrying, and will report when she can—if she can . . .” His voice trailed off.
“You are quite sure?”
“No, not quite, dammit.” Hugh pursed his lips grimly. “But with Thrasher and Splasher on the way, that’s how I’m going to have to play it. Give me all the resolution you can in your images, and all the sense you can make out of any conversation you hear.”
“Of course.”
“And if I jump off the raft and start swimming toward them, tell me I’m an idiot.”
“Why? You will know it already. I will merely direct you back here, as soon as you are far enough away to need it.”
“Then I’ll go the other way.”
“I know.”
That silenced Hugh, whose attention had never really wandered from the display. The swimmers were closing in on their target, now, and visible in the special display. The Box had deleted the vertical current symbols to clear the view for the Erthuma, but there was still a good deal of ambiguity that it kept resolving now one way and now another as the weight of incoming evidence, in the form of sound waves of varying frequency and phase, kept shifting.
The electronic intelligence seemed sure that the dangling object was a driver rather than a human form; it had said so. Hugh’s mind recognized the weight of the evidence, but even though he was adult and a scientist his mind wasn’t in full control. Not until he saw the two swimmers close in on the sub without paying attention to what was hanging from it did he relax slightly. At that range the Cephallonians could easily tell either by sight or
sonar what the suspended object was, and if they were concentrating on the craft—
Abruptly the man felt as though his own breathing system were full of diving fluid. Both swimmers suddenly swerved downward toward the suspended object, and their blurred images merged with it and each other. For long, long seconds no change could be seen; then both The Box and through it the Erthuma could tell that the Cephallonians were rising and the submarine once more nosing upward toward a horizontal attitude.
“They’ve asked for guidance back here,” the artificial intelligence reported in its usual calm tone. “What happened?”
“Janice doesn’t know. Something caused all four thrusters to build up to full power almost simultaneously, and the bottom one tore free from most of its lashings. Its weight and the unbalanced push of the top one before she could shut it down caused the sub to nose downward. The hanging thruster had broken its control cable before she could shut it off too, so it was still operating, also pointing down.”
“Why didn’t she cut it loose?”
“I will ask. I would guess she didn’t want to lose the unit, and felt she could pull it back within reach by the lines still holding it. She was in no obvious danger; she is equipped to survive at the full depth of this ocean.”
“Except that the power units were not responding to control.”
“She did manage to shut the three off. No doubt, though, that is why the Cephallonians think she should return. There was argument, though I could not hear all of it.”
“At least Jan’s all right.”
“It seems so. I expect her main trouble will be annoyance, if she has not been able to decide why the thrust units went out of control.”
“You have no idea?”
“None. They worked perfectly driving the raft, and I can see no reason why a change in mount should make a difference. Intake and discharge areas were clear on the submarine, if anything clearer than on the raft. The thrusters and fusers are complete units. Nothing like intake filters, ion dischargers, or electrolyzers are separate, so nothing could have been omitted inadvertently during transfer.
“Since none of us is a mechanic, that’s just as well. I guess you’re right, then. If Jan hasn’t figured it out by then, she’ll be highly incensed when she gets here. D’you mind if I arrange for her to take it out on you?”
“I don’t mind, but doubt that you’ll fool her that easily.”
“So do I,” Hugh answered gloomily.
But if Janice were angry, she hid it well. She had no explanation for the misbehavior of the drivers, though she felt normal scientific curiosity about the matter. She would also have liked on purely practical grounds to be able to use them in saving the lives of the group. However, she was a rational person, and having accepted that they were not trustworthy she had already dismissed them from consideration. She was still as concerned as the rest over what should be done next, and her remarks focused on this.
They were all feeling increasingly that while time was not exactly standing over them with a poised axe, it was in the front row of seats with a guess-where-I-put-my-money smile on its face.
“I hate to say it,” Janice keyed as she reboarded the raft, “but I’m afraid the juice had better go back in the tank. No more diving, little more project. We need to get our present information home, not to mention ourselves. Then we can carry on with better-planned equipment.”
Her husband certainly did not object, and they set to work. Getting the last of the chemical out of her system took time and care, and several hours of therapy were needed to restore Janice’s damped-out reflexes. Both of them were now experienced at this, however, and the Cephallonians could continue some project work in the meantime.
Janice marked the completion of the therapy by a couple of hours of acute seasickness; the nausea she had been firmly holding back for over two weeks ran wild, probably with some aid from her imagination. Then, with firsthand assurance that her antichoking reflexes were working as they should, both Erthumoi were able to turn their minds back to the survival problem.
“Box, why couldn’t Thrasher or Splasher swim back to the continent if we made a small raft for one of their fermenters? Couldn’t they maintain an average speed higher than the incoming current?” Janice asked, rejoicing in her voice. This had been suggested before, but not with the tow detail.
“Not even with the most efficiently streamlined raft we could make,” replied The Box unequivocally. “Food would not be the limit. They would run out of oxygen much more quickly. The air here is less breathable for them than for Erthumoi, power is needed to separate oxygen for their suits, and you have said that we can’t rely on the power units.”
“We have been relying on them for that,” Hugh pointed out.
“Only here on the raft. We don’t know why they didn’t work away from the raft,” his wife insisted. “The Cephs couldn’t possibly carry tanks enough for the trip even if we had enough or could make them. They’d need separating equipment and pumps—power. We can’t take that chance. They were able to pull me out of trouble when it happened only a few kilos away, but who rescues one of them a quarter of the way to The Iris?”
“We expect to take chances.” Thrasher considered his professional conscience as good as that of Janice.
“Reasonable chances only. If the rescue effort fails, we all die, the rescuer in some possibly interesting fashion and the rest starving while we wait and wonder. We already know the fusers are unreliable in travel, even if we don’t know why. If someone does figure that out, it’s a new game; but until that happens we count them out.” Janice was firm, and Thrasher, who had not been really enthusiastic about towing a raft of equipment and food, said no more. His wife, however, cut in rather pointedly.
“Where is all this leading? Someone has to take a chance, and no one has suggested any way of getting out, except swimming, which doesn’t use power units. I assume you’re not suggesting that you Erthumoi swim for it—or row. You’d make no headway against even the current, much less the wind, even if we could make you a boat.”
“We could manage a boat all right,” Janice said thoughtfully, “After all, we did improvise the sub, and there’s a lot of fabric still on the raft. But you’re probably right about the wind.”
“In principle,” Hugh said thoughtfully, “I suppose one could use wind power to drive us against the current. We could have some sort of wind turbine which drove another rotor under the surface. The water has more inertia—how about it, Box?”
“Quite possible in principle. Very doubtful as a practical project with the material and tools and, I must regretfully point out, the skills available here.”
Janice raised her eyebrows. “Come on, darling. In my education they stressed the difference between comprehension and craftsmanship.”
“Hmph. In mine they called ‘em mentality and manipulation, and said any time we saw a gap between ‘em we should try to close it.”
“The translators are having trouble,” Thrasher cut in.
“Sorry,” answered Janice, “we went a bit astray. The question is still how to get someone or something to carry news of our troubles to where it has a reasonable chance of being found. You folks need food and oxygen in huge amounts, we Erthumoi can’t travel far or fast under our own power, and The Box—hmmm. What can’t it do?”
“It can’t handle emergencies,” the artificial intelligence pointed out, using third person to keep the Cephallonians a little happier. “It’s the gap Janice mentioned. It can do practically nothing. You could have built connections which would have let it run your submarine, for example, but it could only have called for help if anything went wrong. No real imagination, only preplanned effectors. If you are proposing that it guide a boat back to Iris, the advice is no. The guidance is easy to find, and there would be no food or oxygen problem, but you would have to use a fuser to power the boat; and we are back to our ignorance of just what went wrong.”
“Then we’re stuck, it seems to me,�
� said Hugh. “We can’t use power. It takes power to buck current below the surface. It takes power to buck wind and current at the surface. It takes power to buck wind above the surface—for that matter it takes power to fly at all. And we can’t use—”
“Does it?” Janice perked up suddenly.
“Does it what?” both Cephallonians asked simultaneously. Hugh knew his wife well enough to resolve the ambiguity.
“Yes. It takes power to fly,” he said firmly.
“No. There are plenty of vertical currents in the air as well as the water. A sailplane can use them—”
“If the pilot can find them. And are you suggesting we can build a sailplane? I know they’re simple basically, and we’ve both flown them, but we’ve never made one—remember your remark about craftsmanship a minute ago. And how would you propose to launch it if we did make it?”
“Kite style, with the Cephallonians pulling. There’s plenty of wind, reason knows.” Janice was wearing a smile that Hugh recognized even through her face protection, but he wasn’t quite ready to give up yet.
“And you think you can fly one here? Where winged natives themselves don’t dare come? Where it isn’t just a matter of looking for another thermal to head for after you reach the top of the first? You know as well as I that Habranha should have been called Chaos—it just looks like an eyeball. There are no simple currents here, air or water!
“Box, will you please straighten out this crazy woman? Could the Cephallonians pull a sailplane fast enough to get it off the water—wait, dear, I’m not done—if it were designed to glide faster than the winds it would have to buck? In this gravity, what sort of shape would it have—what sort of wing loading?”
“Wait, Box!” insisted Janice. “How high would we have to fly to avoid the really strong wind into the evaporation zone? Would we need oxygen? And for how long? Remember the winds aloft carry clouds back toward Darkside.”
