«Tell it to lift the ship-slowly,» he said, and there was a note of urgency in his voice.
Alvin repeated the command. There was no sense of motion; there never was. Then, slowly, the image reformed on the vision screen, though for a moment it was blurred and distorted. But it showed enough to end the argument about landing.
The level plain was level no longer. A great bulge had formed immediately below them-a bulge which was ripped open at the top where the ship had torn free. Huge pseudopods were waving sluggishly across the gap, as if trying to recapture the prey that had just escaped from their clutches. As he stared in horrified fascination, Alvin caught a glimpse of a pulsing scarlet orifice, fringed with whiplike tentacles which were beating in unison, driving anything that came into their reach down into that gaping maw.
Foiled of its intended victim, the creature sank slowly into the ground-and it was then that Alvin realized that the plain below was merely the thin scum on the surface of a stagnant sea.
«What was that-thing?» he gasped.
«I’d have to go down and study it before I could tell you that,» Hilvar replied matter-of-factly. «It may have been some form of primitive animal-perhaps even a relative of our friend in Shalmirane. Certainly it was not intelligent, or it would have known better than to try to eat a spaceship.»
Alvin felt shaken, though he knew that they had been in no possible danger. He wondered what else lived down there beneath that innocent sward, which seemed to positively invite him to come out and run upon its springy surface.
«I could spend a lot of time here,» said Hilvar, obviously fascinated by what he had just seen. «Evolution must have produced some very interesting results under these conditions. Not only evolution, but devolution as well, as higher forms of life regressed when the planet was deserted. By now equilibrium must have been reached and-you’re not leaving already?» His voice sounded quite plaintive as the landscape receded below them.
«I am,» said Alvin. «I’ve seen a world with no life, and a world with too much, and I don’t know which I dislike more.»
Five thousand feet above the plain, the planet gave them one final surprise. They encountered a flotilla of huge, flabby balloons drifting down the wind. From each semitransparent envelope clusters of tendrils dangled to form what was virtually an inverted forest. Some plants, it seemed, in the effort to escape from the ferocious conflict on the surface had learned to conquer the air. By a miracle of adaptation, they had managed to prepare hydrogen and store it in bladders, so that they could lift themselves into the comparative peace. of the lower atmosphere.
Yet it was not certain that even here they had found security. Their downward-hanging stems and leaves were infested with an entire fauna of spidery animals, which must! spend their lives floating far above the surface of the globe, continuing the universal battle for existence on their lonely aerial islands. Presumably they must from time to time have some contact with the ground; Alvin saw one of the great balloons suddenly collapse and fall out of the sky, its broken, envelope acting as a crude parachute. He wondered if this was an accident, or part of the life cycle of these strange entities.
Hilvar slept while they waited for the next planet to approach. For some reason which the robot could not explain to them, the ship traveled slowly-at least by comparison with its Universe-spanning haste-now that it was within a Solar System. It took almost two hours to reach the world that Alvin had chosen for his third stop, and he was a little surprised that any mere interplanetary journey should last so long.
He woke Hilvar as they dropped down into the atmosphere.
«What do you make of that?» he asked, pointing to the vision screen.
Below them was a bleak landscape of blacks and gray, showing no sign of vegetation or any other direct evidence of life. But there was indirect evidence; the low hills an shallow valleys were dotted with perfectly formed hemispheres, some of them arranged in complex, symmetrical patterns.
They had learned caution on the last planet, and aft carefully considering all the possibilities remained high in the atmosphere while they sent the robot down to investigate. Through its eyes, they saw one of the hemispheres approach until the robot was floating only a few feet awa from the completely smooth featureless surface.
There was no sign of any entrance, nor any hint of the pur pose which the structure served. It was quite large– a hundred feet high; some of the other hemispheres we larger still. If it was a building, there appeared to be no wa in or out.
After some hesitation, Alvin ordered the robot to move forward and touch the dome. To his utter astonishment, it refused to obey him. This indeed was mutiny-or so at sight it seemed.
«Why won’t you do what I tell you?» asked Alvin, wh he had recovered from his astonishment.
«It is forbidden,» came the reply.
«Forbidden by whom?»
«I do not know.»
«Then how-no, cancel that. Was the order built into you?»
«No.»
That seemed to eliminate one possibility. The builders of these domes might well have been the race who made the robot, and might have included this taboo in the machine’s original instructions.
«When did you receive the order?» asked Alvin.
«I received it when I landed.»
Alvin turned to Hilvar, the light of a new hope burning in his eyes.
«There’s intelligence here! Can you sense it?»
«No,» Hilvar replied. «This place seems as dead to me as the first world we visited.»
«I’m going outside to join the robot. Whatever spoke to it may speak to me.»
Hilvar did not argue the point, though he looked none too happy. They brought the ship to earth a hundred feet away from the dome, not far from the waiting robot, and opened the air lock.
Alvin knew that the lock could not be opened unless the ship’s brain had already satisfied itself that the atmosphere was breathable. For a moment he thought it had made a mistake-the air was so thin and gave such little sustenance to his lungs. Then, by inhaling deeply, he found that he could grasp enough oxygen to survive, though he felt that a few minutes here would be all that be could endure.
Panting hard, they walked up to the robot and to the curving wall of the enigmatic dome. They took one more stepthen stopped in unison as if hit by the same sudden blow. In their minds, like the tolling of a mighty gong, had boomed a single message:
That was all. It was a message not in words, but in pure thought. Alvin was certain that any creature, whatever its level of intelligence, would receive the same warning, in the same utterly unmistakable fashion-deep within its mind.
It was a warning, not a threat. Somehow they knew that it was not directed against them; it was for their own protection.
Here, it seemed to say, is something intrinsically dangerous, and we, its makers, are anxious that no one shall be hurt through blundering ignorantly into it.
Alvin and Hilvar stepped back several paces, and looked at each other, each waiting for the other to say what was in his mind. Hilvar was the first to sum up the position.
«I was right, Alvin,» he said. «There is no intelligence here. That warning is automatic-triggered by our presence when we get too close.»
Alvin nodded in agreement.
«I wonder what they were trying to protect,» he said.: «There could be buildings-anything-Under these domes.»
«There’s no way we can find out, if all the domes warn us off. It’s interesting-the difference between the three planets we’ve visited. They took everything away from the first-they abandoned the second without bothering about it -but they went to a lot of trouble here. Perhaps they expected to come back some day, and wanted everything to be ready for them when they returned.»