On Earth, the glaciers came and went, while above them, the changeless Moon still carried its secret. With a yet slower rhythm than the Polar ice, the tide of civilization ebbed and flowed across the galaxy.
Strange and beautiful and terrible empires rose and fell, and passed on their knowledge to their successors. Earth was not forgotten, but it was one of a million silent worlds, a few of which would ever speak.
Then the first explorers of Earth, recognising the limitations of their minds and bodies, passed on their knowledge to the great machines they had created, and who now transcended them in every way.
For a few thousand years, they shared their Universe with their machine children; then, realizing that it was folly to linger when their task was done, they passed into history without regret.
Not one of them ever looked through his own eyes upon the planet Earth again. But even the age of the Machine Entities passed swiftly.
In their ceaseless experimenting, they had learned to store knowledge in the structure of space itself, and to preserve their thoughts for eternity in frozen lattices of light.
They could become creatures of radiation, free at last from the tyranny of matter. Now, they were Lords of the galaxy, and beyond the reach of time.
They could rove at will among the stars, and sink like a subtle mist through the very interstices of space. But despite their God-like powers, they still watched over the experiments their ancestors had started so many generations ago.
The companion of Jupiter knew nothing of this, as it orbited in its no man's land. It had only to remember and wait, and to look forever Sunward with its strange senses.
For many weeks, it had watched the approaching ship. Its long-dead makers had prepared it for many things and this was one of them.
And it recognised what was climbing starward from the Sun.
If it had been alive, it would have felt excitement, but such an emotion was irrelevant to its great powers.
Even if the ship had passed it by, it would not have known the slightest trace of disappointment.
It had waited four million years; it was prepared to wait for eternity.
Presently, it felt the gentle touch of radiations, trying to probe its secrets.
Now, the ship was in orbit and it began to speak, with prime numbers from one to eleven, over and over again.
Soon, these gave way to more complex signals at many frequencies, ultra-violet, infra-red, X-rays.
The machine made no reply.
It had nothing to say.
Then it saw the first robot probe, which descended and hovered above the chasm.
Then, it dropped into darkness.
The great machine knew that this tiny scout was reporting back to its parent.
But it was too simple, too primative a device to detect the forces that were gathering around it now.
Then the pod came, carrying life.
The great machine searched its memories.
The logic circuits made their decision when the pod had fallen beyond the last faint glow of the reflected Jupiter light.
In a moment of time, too short to be measured, space turned and twisted upon itself.
END OF SCREENPLAY