"You were to have come back to the far upwhen after the barrier at the 100,000th had been lowered and you did. But you were to have come back alone. It is for that reason that I was momentarily so startled at seeing Computer TwisseIl with you."

Again Harlan was troubled. How she made things fit in!

Noys said, "I would have been even more startled, had I realized the significance of that alteration in full. Had you come alone, you would have brought me back to the Primitive as you did. Then, for love of humanity, for love of me, you would have left Cooper untouched. Your circle would have been broken, Eternity ended, our life together here safe.

"But you came with Twissell, a chance variation. While coming, he talked to you of his thoughts about the Hidden Centuries and started you on a train of deductions that ended with your doubting my good faith. It ended with a blaster between us. . . . And now, Andrew, that's the story. You may blast me. There is nothing to stop you."

Harlan's hand ached from its spastic grasp on the blaster. He shifted it dizzily to the other hand. Was there no flaw in her story? Where was the resolution he was to have gained from knowing certainly that she was a creature of the Hidden Centuries. He was more than ever tearing at himself in conflict and dawn was approaching.

He said, "Why two efforts to end Eternity? Why couldn't Eternity have ended once and for all when I sent Cooper back to the 20th?" Things would have ended then and there would not have been this agony of uncertainty."

"Because," said Noys, "ending this Eternity is not enough. We must reduce the probability of establishing any form of Eternity to as near zero as we can manage. So there is one thing we must do here in the Primitive. A small Change, a little thing. You know what a Minimum Necessary Change is like. It is only a letter to a peninsula called Italy here in the 20th. It is now the 19.32nd. In a few Centicenturies, provided I send the letter, a man of Italy will begin experimenting with the neutronic bombardment of uranium."

Harlan found himself horrified. "You will alter Primitive history?"

"Yes. It is our intention. In the new Reality, the final Reality, the first nuclear explosion will take place not in the 30th Century but in the 19.45th."

"But do you know the danger? Can you possibly estimate the danger?"

"We know the danger. We have viewed the sheaf of resulting Realities. There is a probability, not a certainty, of course, that Earth will end with a largely radioactive crust, but before that----"

"You mean there can be compensation for that?"

"A Galactic Empire. An actual intensification of the Basic State."

"Yet you accuse the Eternals of interfering----"

"We accuse them of interfering many times to keep mankind safely at home and in prison. We interfere once, once, to turn him prematurely to nucleonics so that he might never, _never_, establish an Eternity."

"No," said Harlan desperately. "There must be an Eternity."

"If you choose. It is yours to choose. If you wish to have psychopaths dictate the future of man--"

"_Psychopaths!_" exploded Harlan.

"Aren't they? You know them. Think!"

Harlan stared at her in outraged horror, yet he could not help thinking. He thought of Cubs learning the truth about Reality and Cub Latourette trying to kill himself as a result. Latourette had survived to become an Eternal, with what scars on his personality none could say, yet helping to decide on alternate Realities.

He thought of the caste system in Eternity, of the abnormal life that turned guilt feelings into anger and hatred against Technicians. He thought of Computers, struggling against themselves, of Finge intriguing against Twissell and Twissell spying on Finge. He thought of Sennor, fighting his bald head by fighting all the Eternals.

He thought of himself.

Then he thought of Twissell, the great Twissell, also breaking the laws of Eternity.

It was as though he had always known Eternity to be all this. Why else should he have been so willing to destroy it? Yet he had never admitted it to himself fully; he had never looked it clearly in the face, until, suddenly, now.

And he saw Eternity with great clarity as a sink of deepening psychoses, a writhing pit of abnormal motivation, a ma.s.s of desperate lives torn brutally out of context.

He looked blankly at Noys.

She said softly, "Do you see? Come to the mouth of the cave with me, Andrew?"

He followed her, hypnotized, appalled at the completeness with which he had gained a new viewpoint. His blaster fell away from the line connecting it and Noys's heart for the first time.

The pale streakings of dawn grayed the sky, and the bulking kettle just outside the cave was an oppressive shadow against the pallor. Its outlines were dulled and blurred by the film thrown over it.

Noys said, "This is Earth. Not the eternal and only home of mankind, but only a starting point of an infinite adventure. All you need do is make the decision. It is yours to make. You and I and the contents of this cave will be protected by a physiotime field against the Change. Cooper will disappear along with his advertis.e.m.e.nt; Eternity will go and the Reality of my Century, but we will remain to have children and grandchildren, and mankind will remain to reach the stars."

He turned to look at her, and she was smiling at him. It was Noys as she had been, and his own heart beating as it had used to.

He wasn't even aware that he had made his decision until the grayness suddenly invaded all the sky as the hulk of the kettle disappeared from against it.

With that disappearance, he knew, even as Noys moved slowly into his arms, came the end, the final end of Eternity.

--And the beginning of Infinity.