Against the Fall of Night by Arthur C. Clarke Page A

except these two disappeared. The one on the right is the original.”

Eleven
The Council
    Alvin was still stunned, but slowly he began to realize what must have happened. His robot could not be forced to disobey the orders given it so long ago, but a duplicate could be made with all its knowledge yet with the unbreakable memory-block removed. Beautiful though the solution was, the mind would be unwise to dwell too long upon the powers that made it possible.
    The robots moved as one when Alvin called them towards him. Speaking his commands, as he often did for Rorden’s benefit, he asked again the question he had put so many times in different forms.
    “Can you tell me how your first master reached Shalmirane?”
    Rorden wished his mind could intercept the soundless replies, of which he had never been able to catch even a fragment. But this time there was little need, for the glad smile that spread across Alvin’s face was sufficient answer.
    The boy looked at him triumphantly.
    “Number One is just the same,” he said, “but Two is willing to talk.”
    “I think we should wait until we’re home again before we begin to ask questions,” said Rorden, practical as ever. “We’ll need the Associators and Recorders when we start.”
    Impatient though he was, Alvin had to admit the wisdom of the advice. As he turned to go, Rorden smiled at his eagerness and said quietly:
    “Haven’t you forgotten something?”
    The red light on the Interpreter was still flashing, and its message still glowed on the screen.
    PLEASE CHECK AND SIGN
    Alvin walked to the machine and examined the panel above which the light was blinking. Set in it was a window of some almost invisible substance, supporting a stylus which passed vertically through it. The point of the stylus rested on a sheet of white material which already bore several signatures and dates. The last of them was almost fifty thousand years ago, and Alvin recognized the name as that of a recent President of the Council. Above it only two other names were visible, neither of which meant anything to him or to Rorden. Nor was this very surprising, for they had been written twenty-three and fifty-seven million years before.
    Alvin could see no purpose for this ritual, but he knew that he could never fathom the workings of the minds that had built this place. With a slight feeling of unreality he grasped the stylus and began to write his name. The instrument seemed completely free to move in the horizontal plane, for in that direction the window offered no more resistance than the wall of a sap-bubble. Yet his full strength was incapable of moving it vertically: he knew, because he tried.
    Carefully he wrote the date and released the stylus. It moved slowly back across the sheet to its original position—and the panel with its winking light was gone.
    As Alvin walked away, he wondered why his predecessors had come here and what they had sought from the machine. No doubt, thousands or millions of years in the future, other men would look into that panel and ask themselves: “Who was Alvin of Loronei?” Or would they? Perhaps they would exclaim instead: “Look! Here’s Alvin’s signature!”
    The thought was not untypical of him in his present mood, but he knew better than to share it with his friend.
    At the entrance to the corridor they looked back across the cave, and the illusion was stronger than ever. Lying beneath them was a dead city of strange white buildings, a city bleached by the fierce light not meant for human eyes. Dead it might be, for it had never lived, but Alvin knew that when Diaspar had passed away these machines would still be here, never turning their minds from the thoughts greater men than he had given them long ago.
    They spoke little on the way back through the streets of Diaspar, streets bathed with sunlight which seemed pale and wan after the glare of the machine city. Each in his own way was thinking of the knowledge that would soon be his, and