"We in Eternity commandeered the instrument for our own purposes. At that time, there were only about six or seven hundred Sections built up. We had plans for expansion, of course. 'Ten new Sections a physioyear' was one of the slogans of the time. The mass duplicator made that all unnecessary. We built one new Section complete with food, power supply, water supply, all the best automatic features; set up the machine and duplicated the Section once each Century all along Eternity. I don't know how long they kept it going-millions of Centuries, probably."

"All like this, Andrew?"

"All exactly like this. And as Eternity expands, we just fill in, adapting the construction to whatever fashion turns out to be current in the Century. The only troubles come when we hit an energy-centered Century. We-we haven't reached this Section yet." (No use telling her that the Eternals couldn't penetrate into Time here in the Hidden Centuries. What difference did that make?)

He glanced at her and she seemed troubled. He said hastily, "There's no waste involved in building the Sections. It took energy, nothing more, and with the nova to draw on-"

She interrupted. "No. I just don't remember."

"Remember what?"

"You said the duplicator was invented in the 300's. We don't have it in the 482nd. I don't remember viewing anything about it in history."

Harlan grew thoughtful. Although she was within two inches of being as tall as himself, he suddenly felt giant-size by comparison. She was a child, an infant, and he was a demigod of Eternity who must teach her and lead her carefully to the truth.

He said, "Noys, dear, let's find a place to sit down and-and I'll have to explain something."

The concept of a variable Reality, a Reality that was not fixed and eternal and immutable was not one that could be faced casually by anyone.

In the dead of the sleep period, sometimes, Harlan would remember the early days of his Cubhood and recall the wrenching attempts to divorce himself from his Century and from Time.

It took six months for the average Cub to learn all the truth, to discover that he could never go home again in a very literal way. It wasn't Eternity's law, alone, that stopped him, but the frigid fact that home as he knew it might very well no longer exist, might, in a sense, never have existed.

It affected Cubs differently. Harlan remembered Bonky Latourette's face turning white and gaunt the day Instructor Yarrow had finally made it unmistakably clear about Reality.

None of the Cubs ate that night. They huddled together in search of a kind of psychic warmth, all except Latourette, who had disappeared. There was a lot of false laughter and miserably poor joking.

Someone said with a voice that was tremulous and uncertain, "I suppose I never had a mother. If I go back into the 95th, they'd say: 'Who are you? We don't know you. We don't have any records of you. You don't exist.'"

They smiled weakly and nodded their heads, lonely boys with nothing left but Eternity.

They found Latourette at bedtime, sleeping deeply and breathing shallowly. There was the slight reddening of a spray injection in the hollow of his left elbow and fortunately that was noted too.

Yarrow was called and for a while it looked as though one Cub would be out of the course, but he was brought around eventually. A week later he was back in his seat. Yet the mark of that evil night was on his personality for as long as Harlan knew him thereafter.

And now Harlan had to explain Reality to Noys Lambent, a girl not much older than those Cubs, and explain it at once and in full. He had to. There was no choice about that. She must learn exactly what faced them and exactly what she would have to do.

He told her. They ate canned meats, chilled fruits, and milk at a long conference table designed to hold twelve, and there he told her.

He did it as gently as possible, but he scarcely found need for gentleness. She snapped quickly at every concept and before he was half through it was borne in upon him, to his great amazement, that she wasn't reacting badly. She wasn't afraid. She showed no sense of loss. She only seemed angry.

The anger reached her face and turned it a glowing pink while her dark eyes seemed somehow the darker for it.

"But that's criminal," she said. "Who are the Eternals to do this?"

"It's done for humanity's good," said Harlan. Of course, she couldn't really understand that. He felt sorry for the Time-bound thinking of a Timer.

"Is it? I suppose that's how the mass duplicator was wiped out."

"We have copies still. Don't worry about that. We've preserved it."

"You've preserved it. But what about us? We of the 482nd might have had it." She gestured with little movements of two clenched fists.

"It wouldn't have done you good. Look, don't be excited, dear, and listen." With an almost convulsive gesture (he would have to learn how to touch her naturally, without making the movement seem a sheepish invitation to a repulse) he took her hands in his and held them tightly.

For a moment she tried to free them, and then she relaxed. She even laughed a bit. "Oh, go ahead, silly, and don't look so solemn. I'm not blaming you."

"You mustn't blame anyone. There is no blame necessary. We do what must be done. That mass duplicator is a classic case. I studied it in school. When you duplicate mass, you can duplicate persons, too. The problems that arise are very complicated."

"Isn't it up to the society to solve its own problems?"

"It is, but we studied that society throughout Time and it doesn't solve the problem satisfactorily. Remember that its failure to do so affects not only itself but all its descendant societies. In fact, there is no satisfactory solution to the mass-duplicator problem. It's one of those things like atomic wars and dreamies that just can't be allowed. Developments are never satisfactory."

"What makes you so sure?"

"We have our Computing machines, Noys; Computaplexes far more accurate than any ever developed in any single Reality. These Compute the possible Realities and grade the desirabilities of each over a summation of thousands and thousands of variables."

"Machines!" She said it with scorn.

Harlan frowned, then relented hastily. "Now don't be like that. Naturally, you resent learning that life is not as solid as you thought. You and the world you lived in might have been only a probability shadow a year ago, but what's the difference? You have all your memories, whether they're of probability shadows or not, haven't you? You remember your childhood and your parents, don't you?"

"Of course."

"Then it's just as if you lived it, isn't it? Isn't it? I mean, whether you did or not?"

"I don't know. I'll have to think about it. What if tomorrow it's a dream world again, or a shadow, or whatever you call it?"

"Then there would be a new Reality and a new you with new memories. It would be just as though nothing had happened, except that the sum of human happiness would have been increased again."

"I don't find that satisfying, somehow."

"Besides," said Harlan hastily, "nothing will happen to you now. There will be a new Reality but you're in Eternity. You won't be changed."

"But you say it makes no difference," said Noys gloomily. "Why go to all the trouble?"

With sudden ardor Harlan said, "Because I want you as you are. Exactly as you are. I don't want you changed. Not in anyway."

He came within a hair of blurting out the truth, that without the advantage of the superstition about Eternals and eternal life she would never have inclined toward him.

She said, looking about with a slight frown, "Will I have to stay here forever, then? It would be-lonely."

"No, no. Don't think it," he said wildly, gripping her hands so tight that she winced. "I'll find out what you will be in the new Reality of the 482nd, and you'll go back in disguise, so to speak. I'll take care of you. I'll apply for permission for formal liaison and see to it that you remain safely through future Changes. I'm a Technician and a good one and I know about Changes." He added grimly, "And I know a few other things as well," and stopped there.