Who had they been? Where had they come from? Alvin could only stare and wonder. He would never know if he had missed these earlier visitors by a thousand or a million years.
They walked in silence back to their own ship (how tiny that would have looked beside the monster which once had rested here!) and flew slowly across the arena until they came to the most impressive of the buildings flanking it. As they landed in front of the ornate entrance, Hilvar pointed out something that Alvin had noticed at the same moment.
«These buildings don’t look safe. See all that fallen stone over there-it’s a miracle they’re still standing. If there were any storms on this planet, they would have been flattened ages ago. I don’t think it would be wise to go inside anyof them.»
«I’m not going to; I’ll send the robot-it can travel far faster than we can, and it won’t make any disturbance which might bring the roof crashing down on top of it.»
Hilvar approved of this precaution, but he also insistet on one which Alvin had overlooked. Before the robot lef on its reconnaissance, Alvin made it pass on a set of instructions to the almost equally intelligent brain of the ship, so that whatever happened to their pilot they could at least return safely to Earth.
It took little time to convince both of them that this work had nothing to offer. Together they watched miles of empty dust-carpeted corridors and passageways drift across thd screen as the robot explored these empty labyrinths. All buildings designed by intelligent beings, whatever form their bodied may take, must comply with certain basic laws, and after i while even the most alien forms of architecture or design fail to evoke surprise, and the mind becomes hypnotized by sheet repetition, incapable of absorbing any more impressions. These buildings, it seemed, had been purely residential, and the beings who had lived in them had been approximately humanoid size. They, might well have been men; it was true that there were a surprising number of rooms and enclosures that could be entered only by flying creatures, but that did not mean that the builders of this city were winged. They could have used the personal antigravity devices that had once been in common use but of which there was now no trace in Diaspar.
«Alvin,» said Hilvar at last, «we could spend a million years exploring these buildings. It’s obvious that they’ve not merely been abandoned-they were carefully stripped of everything valuable that they possessed. We are wasting our time.»
«Then what do you suggest?» asked Alvin.
«We should look at two or three other areas of this planet and see if they are the same-as I expect they are. Then we should make an equally quick survey of the other planets, and only land if they seem fundamentally different or we notice something unusual. That’s all we can hope to do unless we are going to stay here for the rest of our lives.»
It was true enough; they were trying to contact intelligence, not to carry out archaeological research. The former task could be achieved in a few days, if it could be achieved at all. The latter would take centuries of labor by armies of men and robots.
They left the planet two hours later, and were thankful enough to go. Even when it had been bustling with life, Alvin decided, this world of endless buildings would have been very depressing. There were no signs of any parks, any open spaces where there could have been vegetation. It had been an utterly sterile world, and it was hard to imagine the psychology of the beings who had lived here. If the next planet was identical with this, Alvin decided, he would probably abandon the search there and then.
It was not; indeed, a greater contrast would have been impossible to imagine.
This planet was nearer the sun, and even from space it looked hot. It was partly covered with low clouds, indicating that water was plentiful, but there were no signs of any oceans. Nor was there any sign of intelligence; they circled the planet twice without glimpsing a single artifact of any kind. The entire globe, from poles down to the equator, was clothed with a blanket of virulent green.
«I think we should be very careful here,» said Hilvar. «This world is alive-and I don’t like the color of that vegetation. It would be best to stay in the ship, and not to open the air lock at all.»
«Not even to send out the robot?»
«No, not even that. You have forgotten what disease is, and though my people know how to deal with it we are a long way from home and there may be dangers here which we cannot see. I think this is a world that has run amok. once it may have been all one great garden or park, back when it was abandoned Nature took over again. It could never have been like this while the system was inhabited.»
Alvin did not doubt that Hilvar was right. There was some thing evil, something hostile to all the order and regularity on which Lys and Diaspar were based, in the biological an . archy below. Here a ceaseless battle had raged for a billion years; it would be well to be wary of the survivors.
They came cautiously down over a great level plain, so uniform that its flatness posed an immediate problem. The plain was bordered by higher ground, completely cover with trees whose height could only be guessed-they were so tightly packed, and so enmeshed with undergrowth, that their trunks were virtually buried. There were so many winged creatures flying among their upper branches, though they moved so swiftly that it was impossible to tell whether the were birds or insects-or neither.
Here and there a forest giant had managed to climb a few scores of feet above its battling neighbors, who had formed a brief alliance to tear it down and destroy the advantage it had won. Despite the fact that this was a silent war, fought, too slowly for the eye to see, the impression of merciless, im placable conflict was overwhelming.
The plain by comparison, appeared placid and uneventful. It was flat, to within a few inches, right out to the horizon; and seemed to be covered with a thin, wiry grass. Though they descended to within fifty feet of it, there was no sign of any animal life, which Hilvar found somewhat surprising. Perhaps, he decided, it had been scared underground by their approach.
They hovered just above the plain while Alvin tried to convince Hilvar that it would be safe to open the air lock, and Hilvar patiently explained such conceptions as bacteria, fungi, viruses, and microbes-ideas which Alvin found hard to visualize, and harder still to apply to himself. The argument had been in progress for some minutes before they noticed peculiar fact. The vision screen, which a moment ago ha been showing the forest ahead of them, had now becom blank.
«Did you turn that off?» said Hilvar, his mind, as usu just one jump ahead of Alvin’s.
«No,» replied Alvin, a cold shiver running down his spin as he thought of the only other explanation. «Did you turn it off?» he asked the robot.
«No,» came the reply, echoing his own.
With a sigh of relief, Alvin dismissed the idea that t robot might have started to act on its own volition-then he might have a mechanical mutiny on his hands.
«Then why is the screen blank?» he asked.
«The image receptors have been covered.»
«I don’t understand,» said Alvin, forgetting for a m ment that the robot would only act on definite orders or questions. He recovered himself quickly and asked: «What’s covered the receptors?»
«I do not know.»
The literal-mindedness of robots could sometimes be as exasperating as the discursiveness of humans. Before Alvin could continue the interrogation Hilvar interrupted.