"Without advanced mathematical training? I've watched you closely for years, boy, and would not have guessed that particular talent of yours. Go on."

"Eternity could never have been established without Mallansohn's discovery of the Temporal Field. Mallansohn could never have accomplished this without a knowledge of mathematics that existed only in his future. That's number one. Meanwhile, here in Eternity at this moment, there is a Cub who was selected as an Eternal against all the rules, since he was overage and married, to boot. You are educating him in mathematics and in Primitive sociology. That's number two."

"Well?"

"I say that it is your intention to send him back into Time somehow, back past the downwhen terminus of Eternity, back to the 24th. It is your intention to have the Cub, Cooper, teach the Lefebvre equations to Mallansohn. You see, then," Harlan added with tense passion, "that my own position as expert in the Primitive and my knowledge of that position entitles me to special treatment. Very special treatment."

"Father Time!" muttered Twissell.

"It's true, isn't it? We come full circle, _with my help_. Without it…" He let the sentence hang.

"You come so close to the truth," said Twissell. "Yet I could swear there was nothing to indicate--" He fell into a study in which neither Harlan nor the outside world seemed to play a part.

Harlan said quickly, "Only close to the truth? It is the truth." He could not tell why he was so certain of the essentials of what he said, even quite apart from the fact that he so desperately wanted it to be so.

Twissell said, "No, no, not the exact truth. The Cub, Cooper, is not going back to the 24th to teach Mallansohn anything."

"I don't believe you."

"But you must. You must see the importance of this. I want your co-operation through what is left of the project. You see, Harlan, the situation is more full circle than you imagine. Much more so, boy. Cub Brinsley Sheridan Cooper is Vikkor Mallansohn!"

Harlan would not have thought that Twissell could have said anything at that moment that could have surprised him. He was wrong.

He said, "Mallansohn. He-"

Twissell, having smoked his cigarette to a stub, produced another and said, "Yes, Mallansohn. Do you want a quick summary of Mallansohn's life? Here it is. He was born in the 78th, spent some time in Eternity, and died in the 24th."

Twissell's small hand placed itself lightly on Harlan's elbow and his gnomish face broke into a wrinkled extension of his usual smile. "But come, boy, physiotime passes even for us and we are not completely masters of ourselves this day. Won't you come with me to my office?"

He led the way and Harlan followed, not entirely aware of the opening doors and the moving ramps.

He was relating the new information to his own problem and plan of action. With the passing of the first moment of disorientation his resolution returned. After all, how did this change things except to make his own importance to Eternity still more crucial, his value higher, his demands more sure to be met, Noys more certain to be bartered back to him.

Noys!

Father Time, they must not harm her! She seemed the only real part of his life. All Eternity beside was only a filmy fantasy, and not a worth-while one, either.

When he found himself in Computer Twissell's office, he could not clearly recall how it had come about that he had passed from the dining area here. Though he looked about and tried to make the office grow real by sheer force of the mass of its contents, it still seemed but another part of a dream that had outlived its usefulness.

Twissell's office was a clean, long room of porcelain asepsis. One wall of the office was crowded from floor to ceiling and wall to distant wall with the computing micro-units which, together, made up the largest privately operated Computaplex in Eternity and, indeed, one of the largest altogether. The opposite wall was crammed with reference films. Between the two what was left of the room was scarcely more than a corridor, broken by a desk, two chairs, recording and projecting equipment, and an unusual object the like of which Harlan was not familiar with and which did not reveal its use until Twissell flicked the remnants of a cigarette into it.

It flashed noiselessly and Twissell, in his usual prestidigitational fashion, held another in his hands.

Harlan thought: To the point, now.

He began, a trifle too loudly, a bit too truculently, "There is a girl in the 482nd--"

Twissell frowned, waved one hand quickly as though brushing an unpleasant matter hastily to one side. "I know, I know. She will not be disturbed, nor you. All will be well. I will see to it."

"Do you mean--"

"I tell you I know the story. If the matter has troubled you, it need trouble you no more."

Harlan stared at the old man, stupefied. Was this all? Though he had thought intently of the immensity of his power, he had not expected so clear a demonstration.

But Twissell was talking again.

"Let me tell you a story," he began, with almost the tone he would have used in addressing a newly inducted Cub. "I had not thought this would be necessary, and perhaps it still isn't, but your own researches and insight deserve it."

He stared at Harlan quizzically and said, "You know, I still can't quite believe that you worked this out on your own," then went on:

"The man most of Eternity knows as Vikkor Mallansohn left the record of his life behind him after he died. It was not quite a diary, not quite a biography. It was more of a guide, bequeathed to the Eternals he knew would someday exist. It was enclosed in a volume of Time-stasis which could be opened only by the Computers of Eternity, and which therefore remained untouched for three Centuries after his death, until Eternity was established and Senior Computer Henry Wadsman, the first of the great Eternals, opened it. The document has been passed along in strictest security since, along a line of Senior Computers ending with myself. It is referred to as the Mallansohn memoir.

"The memoir tells the story of a man named Brinsley Sheridan Cooper, born in the 78th, inducted as a Cub into Eternity at the age of twenty-three, having been married for a little over a year, but having been, as yet, childless.

"Having entered Eternity, Cooper was trained in mathematics by a Computer named Laban Twissell and in Primitive sociology by a Technician named Andrew Harlan. After a thorough grounding in both disciplines, and in such matters as temporal engineering as well, he was sent back to the 24th to teach certain necessary techniques to a Primitive scientist named Vikkor Mallansohn.

"Once having reached the 24th, he embarked first on a slow process of adjusting himself to the society. In this he benefited a great deal from the training of Technician Harlan and the detailed advice of Computer Twissell, who seemed to have an uncanny insight into some of the problems he was to face.

"After the passage of two years, Cooper located one Vikkor Mallansohn, an eccentric recluse in the California backwoods, relationless and friendless but gifted with a daring and unconventional mind. Cooper made friends slowly, acclimated the man to the thought of having met a traveler from the future still more slowly, and set about teaching the man the mathematics he must know.

"With the passage of time, Cooper adopted the other's habits, learned to shift for himself with the help of a clumsy Diesel-oil electric generator and with wired electrical appliances which freed them of dependence on power beams.

"But progress was slow and Cooper found himself something less than a marvelous teacher. Mallansohn grew morose and unco-operative and then one day died, quite suddenly, in a fall down a canyon of the wild, mountainous country in which they lived. Cooper, after weeks of despair, with the ruin of his lifework and, presumably, of all Eternity, staring him in the eye, decided on a desperate expedient. He did not report Mallansohn's death. Instead, he slowly took to building, out of the materials at hand, a Temporal Field.