The other two couples were equally in a hurry, and neither had as far to go, so they reached the ship first. The trouble was that, once there, no one could think of any really useful apparatus which could be carried, even on Miranda, and which promised to be more effective in communication with a robot than the lights and radios which they already had and the broader-spectrum equipment possessed by Chile. Dumbo was not portable. They had all gone inside, unsuited, and taken care of physical necessities; conversation had been almost continuous through all this, but no really promising suggestions had been made by anyone.
“Who’d have thought we’d need a language specialist?” Luis growled at last.
“How do you know we do?” asked Bronwen. “It may have been made on Earth, by some group we don’t know about.”
“Did you or Rob try ordering it to come back with you?” Chispa asked Sheila.
“Neither of us thought of it. Chile said he’d tried normal robot-to-robot signals with no response, and I guess we were both so convinced it was alien that ordinary speech seemed pointless.”
“You still should have tried.”
“Admitted. We still can, you know. Call Chile and have him order the thing to accompany him back here, in every symbol system he considers appropriate. “
“Will it obey orders from another robot?”
“Will it know Chile’s a robot?”
“Probably. It radiated infrared, and presumably senses it. It should know that he operates at local temperature, and we don’t. The inference would certainly be within Chile’s powers; we don’t know about this one’s, of course.”
“If it’s really alien, it might infer from that that we’re the robots, with inherently wasteful power equipment, and Chile is a native life-form. The trouble is, we don’t know its background,” Mike interjected.
“You’ve got your feet on the wrong pedestal, dear. If we’re trying to give it orders at all, the assumption is that it can understand us, and must be human made.” His wife didn’t dwell on the point, but went on. “We have to try, anyway.” She didn’t bother to check for open channels; there was always one through to the robot. “Chile.”
“Yes, Bronwen.”
“Any change?”
“None. It is standing facing me, presumably waiting for me to do something. It has now cooled down to ambient temperature; I would say that any doubt about its being a robot is gone.”
“You can’t sense an atomic power source?”
“I am not equipped to pick up such radiation directly.”
Bronwen had known that, but was feeling desperate.
“Try talking to it directly-”
“I have done so, every way I can.”
“This time, send your message as an order to approach you. If it responds, order it to follow you back to Dibrofiad. “ There was a brief pause.
“No action, Bronwen.”
“If you had received such an order from it, would you have obeyed?”
“Not without checking that the order had originated from a human being, or obtaining the approval of a human being. “
“So we haven’t proved anything. “ There was no response to this; Chile had no reason to interpret the remark as a question to him, and the human beings recognized its rhetorical nature. An uncomfortable silence ensued.
“Bronwen, let me try something?” Ling finally spoke, in doubtful tones. The commander nodded, not bothering to ask the nature of his idea.,
“Chile, the robot replaced that cube as nearly as possible to the place it was before the cliff broke off. It seems concerned with it. Without going to extremes if it interferes, approach the cube yourself as though you intended to pick it up again, and tell us how it-the robot-responds.”
There was another pause, while six people tried to imagine what was happening twenty kilometers away.
“It has interposed itself between me and the cube, and has been moving to stay so wherever I go.”
“Any body contact?”
“No. You said not to go to extremes. Shall I push it out of my way?” Ling looked thoughtfully first at Bronwen and then the others. The commander’s eyes also met theirs, in turn. Finally she nodded again.
“All right, Chile. No real force, just a suggestive shove.”
“Understood, Bronwen.” Imaginations fired up again.
“The response has been complex. It braced itself to resist my push, after I had made contact; naturally, it had to yield some distance to accomplish this. While it was setting its feet, it emitted a brief, very detailed burst of infrared, of the same general nature as we detected originally from the small cubes. This was immediately followed by a similar signal from elsewhere. It then ceased pushing against me and simultaneously seized my arm and pulled. This sent me over the cliff edge. I am now falling, and will be unable to do anything effective for the next fifty-five seconds.”
Ling blinked, and a grin spread over his face.
“Chile, did you determine the source of that other signal?”
“Direction, not distance. I did not move enough for parallax while it lasted. However, its line touches ground just at the edge of Big Drop, in Block Twenty-five, seventy-one meters from the boundary between that one and Block Thirty-seven.”
“Great. Head for that spot as soon as you’re down. We’ll meet you there.”
“All right, Rob. You no longer want me to keep track of the other robot.” It was not a question.
“Don’t worry. It’ll be keeping track of you, I expect.”
“I see.” So did the others, and there was a general rush to get into armor. There was some delay, however, in going outside.
“Hold it,” Bronwen said firmly before helmets were donned. “We’re going to the Big Drop, and no one could stand a twenty-kilo fall; it would be about four hundred and fifty meters on Earth. I still don’t trust the chains, but we link up this time. “
“How close?” asked Mike.
“Fifty meters for the Gold team, twenty for the rest of us. If anyone but Chile has to get near the edge, Rob’s the best anchor, so Sheila can do it. Fifty meters will give him more room to catch the surface, and us more time to help, if she does go over; twenty is enough for us. I’ll carry the rest of the reel just in case.”
“It won’t reach five percent of the way down that cliff!”
“It would take a couple of minutes to fall five percent of the way. We’ll take the chain.”
Her husband nodded. Sheila had paled a trifle, but said nothing. It was true that Ling was the heaviest of the crew, while she herself was lightest except for Chispa. She had no intention of going nearer the edge than necessary, and certainly none of going over, but Bronwen was right to be foresighted.
The chain links were carbon-filament composite a millimeter thick, preformed in jointless loops half a centimeter long and already interlocked. Neither rope nor cable was practical; no known fiber, organic, metallic, or mineral, would remain flexible at Miranda’s temperature. The link material had a tensile strength of eight hundred kilograms as straight rod under Earth conditions, dropping to about five hundred at seventy Kelvins, with some remaining doubts about its elasticity in that range and more about the nontensile stresses and possible shock brittleness in its looped shape. No one had wanted to make the field test, but an armored person weighed only about two kilograms.
They did not actually link up until a couple of kilometers from the cliff, in the interest of fast travel; but the robots, of course, were there first in spite of the much greater distance they had had to travel. There was no trouble, this time, spotting the goal.
It too was cubical in shape, but twice as tall as most of the explorers. Like the one at Barco, it was projecting a little over the edge, though not by nearly as large a fraction of its size. It was not obvious whether it was merely resting on the surface or, like the other, set in. The ground was lighter in color here, but at the moment not even Ling was paying attention to mineralogy. In fact, the group only glanced briefly at the big cube; everyone’s attention was on the two robots.
These were not standing still waiting, as had been tacitly expected. They were moving around, now slowly, now more rapidly, usually in the very short steps which went with their nearly upright carriage but sometimes leaping straight up for a distance ranging from two or three centimeters to as much as ten °meters, sometimes waving arms or kicking. There was no obvious regularity; if they were dancing, which was the first thought to cross most of the human minds, there seemed to be no tune. For a few seconds after stopping fifty meters away, the six people simply watched in silence, trying to make sense out of the phenomenon. Then Bronwen recovered her practical sense.
“Chile, report. What’s going on?”
ZH50’s answer came at once without causing visible change in his behavior.
“The robot is now exchanging continuous infrared signals with this cube, details of its signals changing as I perform various actions, while its own actions seem to correspond to signals from the cube. I am trying to ascertain the detailed relationship. “
“You mean you’re learning its language?”
“The analogy is weak; there seem no abstractions involved, and I doubt that I could work them out if there were-at least, not by myself. Connected with Dumbo, the chances would be better. It appears that the robot is reporting to the cube, and receiving general instructions for action from the latter.”