Ducem Palver"s blue eyes widened slightly and a faint look of puzzlement came over his cherubic face. "But I understood that you were working on pre-Imperial civilization."

Dr. Nikol Buth smiled tolerantly. "That"s right, Mr. Palver. Pre-First-Imperial. We"re digging back more than thirty thousand years; we"re looking for the origin of the human race."

Palver"s face regained its pleasant impa.s.sivity. "I see. Hm-m-m."

"Do you know anything of the Origin Question, Mr. Palver?" Buth asked.

"Some," admitted Palver. "I believe there are two schools of thought, aren"t there?"

Buth nodded. "The Merger Theory, and the Radiation Theory. According to the Merger Theory, mankind is the natural product of evolution on all worlds with a water-oxygen chemistry and the propertemperatures and gravitational intensities. But according to the Radiation Theory, mankind evolved on only one planet in the galaxy and spread out from that planet after the invention of the first crude hypers.p.a.ce drive. I might point but that the Merger Theory has been all but abandoned by modern scholars."

"And yourself?" Palver asked.

"I agree. The Merger Theory is too improbable; it requires too many impossible coincidences. The Radiation Theory is the only probable-one might almost say the only possible-explanation for the existence of Man in the galaxy."

Palver leaned over and picked up the carrying case which he had placed beside his chair. "I transdeveloped a copy of your "Transformations of Symbolic Psychology and Their Application to Human Migration" It was, in fact, this particular work which decided me to come here to Sol III. I"m not much of a mathematician, myself, you understand, but this reminded me so much of the old legends that...well, I was interested."

Dr. Buth chuckled. "There have been, I recall, legends of invisibility, too-you know, devices which would render a human being invisible to the human eye so that he could go where he pleased, undetected. If you had heard that I had written a paper on the transparency of gla.s.s, would you be interested?"

"I see the connection, of course," said Ducem Palver. "Just how does it apply here?"

"The legend," Buth said, puffing vigorously on his cigar, "concerns a mathematical system which can predict the actions of vast ma.s.ses of people-the entire population of the galaxy.

"My work has nothing to do with prediction whatever-unless you want to call it prediction in reverse. I evolved the" system in order to work backwards, into the past; to discover, not what the human race was going to do, but what it had done. You see, there is one fatal flaw in any mathematical prediction system; if people know what they are supposed to do, they will invariably try to do something else, and that can"t be taken into account in the system. It becomes a positive feedback which automatically destroys the system, you see."

Palver nodded wordlessly, waiting for Dr. Buth to continue.

"But that flaw doesn"t apply to my work because there can"t be any such feedback into the past.

What I have done is trace the human race backwards in time-back more than thirty millennia, through the vast migrations, the movements through the galaxy from one star to another, taking every lead and tracing them all back to their single focal point."

""And have you found that focal point?" Palver asked.

"I have. It is here-Sol III. My system shows positively that this is-must be-the birthplace of the human race."

Ducem Palver looked out the transparent wall at one end of the room. "I understand that archaeologists have always supposed the Origin Planet to be somewhere here in the Sirius Sector, but I wouldn"t have thought such a bleak planet as this would be the one. Still"-he laughed pleasantly-""perhaps that"s why they left."

Dr. Buth allowed his gaze to follow that of his visitor to the windswept, snow-covered terrain outside. "It wasn"t always like this," he said. ""For reasons we haven"t nailed down exactly as yet, this planet shows a definitely cyclic climate. There appear to be long ice ages, followed by short periods of warmth. Perhaps, in the long run, the cycle itself is cyclic; we"re not too sure on that score. At any rate, we"re quite sure that it was fairly warm here, thirty to fifty thousand years ago."

"And before that?" Palver asked.

Buth frowned. "Before that, another ice age, we think. We"ve just barely started, of course. There is a great deal of work yet to be done."

"No doubt. Ah-what have you uncovered, so far?"

Dr. Buth stood up from his chair. "Would you like to see? I"ll show you the lab, if you"d like."

"Thank you," said Ducem Palver, rising. "I"d like very much to see it."

A well-equipped, operating archaeological laboratory is like no other laboratory in the galaxy. This one was, if the term can be used, more than typical. Huge radio dating machines lined one wall, and chemical a.n.a.lyzers filled another. Between them were other instruments of all sizes and shapes and purposes.

The place was busy; machines hummed with power, and some technicians labored over bits of material while others watched recorders attached to the machines in use.

Dr. Buth led his visitor through the room, explaining the function of each instrument briefly. At the end of the room, he opened a door marked: SPECIMEN CHAMBER and led Ducem Palver inside. He waved a hand. "Here are our specimens-the artifacts we"ve dug up."

The room looked, literally, like a junk bin, except that each bit of junk was carefully tagged and wrapped in a transparent film.

"All these things are artifacts of Man"s pre-s.p.a.ce days?" Palver asked.

Buth laughed shortly. "Hardly, Mr. Palver. This planet was a part of the First Empire, you know.

These things date back only ten or eleven thousand years. They prove nothing. They are all from the upper layers of the planet"s strata. They"ve been duly recorded and identified and will doubtlessly be forgotten.

"No, these are not important; it is only below the D-stratum that we"ll find anything of interest."

"The D-stratum?"

"We call it that. D for Destruction. There is an almost continuous layer over the land of this planet, as far as we"ve tested it. It was caused, we believe, by atomic bombardment."

"Atomic bombardment? Allover the planet?" Ducem Palver looked shocked.

"That"s right. It looks as though uncontrolled atomic reactions were set off allover the planet at once. Why? We don"t know. But we do know that the layer is nearly twenty-five thousand years old, and that it does not antedate s.p.a.ce travel."

"How so?"

"Obviously," Buth said dryly, "if such a thing had happened before mankind discovered the hypers.p.a.ce drive, there would be no human race today. Man would have died right here and would never have been heard of again."

"Of course, of course. And what have you found below that...uh...D-stratum?"

A frown came over the archaeologist"s dark eyes. "Hardly anything, as yet. Come over here."

Ducem Palver followed his host across the room to a pair of squat objects that reposed on the floor. They looked like pieces of grayish, pitted rock, crudely dome-shaped, sitting on their flat sides.

From the top of the irregular dome projected a chimney of the same material. They were, Palver estimated, about thirty-six centimeters high, and not quite that big in diameter at their base.

"We haven"t worked on these two yet," Dr. Buth said, "but they"ll probably turn out the same as the one we"ve already sectioned."

"What are they?" Palver asked.

Buth shook his head slowly. "We don"t know. We have no idea what their function might have been. They"re hollow, you notice-you can see the clay in that chimney, which was deposited there during the millennia it lay in the ground.

"See this f.l.a.n.g.e around the bottom? That"s hollow, too. It"s a channel that leads to the interior; it"s connected with this hole back here." He pointed to another hole, about the same size as that in the top of the chimney, but located down near the base. It was perhaps seven centimeters in diameter.

"And you haven"t any definite idea what they were used for?" Palver said.

Buth spread his hands in a gesture of temporary bafflement. "Not yet. Ober Sutt, one of my a.s.sistants, thinks it may have been some sort of combustion chamber. He thinks that gases-hydrogen and oxygen, for instance-might have been fed into it, and the heat utilized for something. Or perhaps they were used to synthesize some product at high temperatures-a rather crude method, but it might have been effective for making...oh, ammonia, maybe. I"m not a chemist, and Sutt knows more about that end of it than I do." "Why does he think it"s a high-temperature reaction chamber? I mean, why high-temperature, specifically?"

Dr. Buth waved his cigar at the objects. "They"re made out of a very crude ceramic, a heavy ma.s.s of fired silicon and aluminum oxides, plus a few other things. They"re eroded, of course, and rather fragile now, but to stand up under all the abuse of three or four hundred centuries, they must have been pretty strong when they were made."

"Perhaps the ceramic was used because of its structural strength?" Palver said, half questioningly.

"That"s doubtful. We know they used metals; there are oxides of iron, copper, zinc, chromium, and aluminum everywhere, in deposits that indicate the metals once formed artifacts of some kind. It wouldn"t be logical to use a ceramic, brittle as it is, when metals were used."

"So you think the combustion chamber idea is the most likely?"

Dr. Buth took a long pull at his cigar and looked abstractedly at the glowing ash. "Well, Ober Sutt puts up a good argument for it, but I don"t know..." He waved again with the cigar. "Those things don"t have any bottom, either, and I don"t think they ever did-not connected directly, at least. Sutt counters that by saying that they must have sat on a ceramic plate of some kind, but so far we haven"t found any of those plates, if they exist."

Palver looked carefully at the two objects, then shrugged. "What else have you found?"

"Aside from a few shards," Dr. Buth said carefully, "that"s all we"ve found below the D-layer.

However, as I said, we"ve just begun."

Back in Buth"s office, Ducem Palver picked up his carrying case, snapped it shut. "Well, I"m sorry to have bothered you, Dr. Buth," he said. "I must admit, however, that the solution of the Origin Question holds little interest for me. The history of the latter part of the First Empire, and that of the Great Interregnum -ah, those are deeply interesting. But, as to how Man came to be spread throughout the galaxy-" He lifted his eyebrows and c.o.c.ked his head to one side. His blue eyes seemed very deep for a moment. "Well, Man is here. I will leave it to others to find out how he got here, eh?"

Dr. Buth smiled tolerantly. "It"s just as well that we"re not all interested in the same thing, isn"t it?"

He walked over to the transparent wall and looked out at the bleak whiteness of the windswept snowscape. "But to me, the fascinating thing about Man is his peculiar drives. Imagine a time when men had no s.p.a.ceships, no modern instruments of any kind. What must it have been like to look out at the stars and feel trapped on one single planet?"

Behind him, Ducem Palver"s voice said: "Perhaps you could draw a parallel from the planet Kaldee. During the Interregnum, they were cut off from the rest of the galaxy; they lost all their history-everything. They knew nothing of the s.p.a.ceship, nor of the stars themselves. They thought those lights in the sky were nothing more than bits of gla.s.s, reflecting the light of their sun. They believed the night sky was a black bowl a few miles above their heads, upon which these pieces of broken gla.s.s were fixed."

"Oh?" said Dr. Buth without turning. " And how did they feel about their isolation?"

"They didn"t know they were isolated. They were quite happy, all things considered. They had no burning desire to leave their planet-indeed, they reserved that privilege for the dead."

Dr. Buth"s brows drew together. "Then what made primitive Man want to leave? Why wasn"t he happy on one planet? What happened?"

And suddenly, it seemed as if his whole mind came to a focus on that one question. Why had they decided to conquer s.p.a.ce? Why? What caused that odd drive in Man?

"I"ve got to know," he said-aloud, but very softly.

Ducem Palver didn"t even seem to hear.

After nearly a full minute, Ducem Palver said quietly, "I must be going now. I wish you success, Dr.

Buth."

"Yes," said Buth, still looking at the icy plain outside. "Yes. Thank you very much, Mr. Palver.

Very much. Good-by."

Ducem Palver left him that way, standing, staring at the whiteness of the landscape of Sol III.

It was an old planet, civilization-wise. Not, thought Dr. Nikol Buth, as old a planet in that respect as Sol III, but old, nonetheless. Before the Interregnum, it had served as the capital of the First Empire, and before that, as the nucleus from which the First Empire had grown. It had once been a mighty world, sheathed in metal and armed with the might of the Galactic Fleet, the center of strength of the First Galactic Empire. And then that Empire had fallen, collapsed in upon itself, and with it had collapsed its capital.

It had been great once. And now?

Now it was beautiful. The capital of the Second Empire was far away in s.p.a.ce, and this old planet was of no consequence whatever. But it was beautiful.

It was a garden planet now, filled with green forests and broad sweeps of gra.s.s and fields of flowers. It was a place where a young man could relax for a few weeks before returning to the busy work of maintaining the Empire, a place where an old man, freed from the seemingly eternal grind, could find peace in doing other, less strenuous work.

Dr. Nikol Buth was such a man. He was old now, and the years had not treated him kindly; now, after thirty years of driving himself towards an unattainable goal, he sought only peace. Here, on this garden world, he would find it.

It wasn"t easy to become a permanent resident here. The planet was an Imperial Protectorate, the personal property of the Emperor himself, although His Imperial Majesty never visited it. Tourists were allowed access to certain parts of it, but there were vast estates reserved for those who had earned the right to spend their last years in quiet and solitude. The right to live here had to be earned, and it had to be granted by the Emperor in person. In his pocket, Dr. Nikol Buth carried a precious doc.u.ment-a signed, sealed Imperial Grant.

He had landed at the terminal-like all s.p.a.ces port terminals, a busy place, even here-and had supervised the shipping of his personal effects to his new home at a little village called Mallow and then had taken an aircar there himself.

At the air depot at Mallow, he had been met by a pleasant young man who had introduced himself as Wilm Faloban-"General factotum and chief of police-for all the need they have of police here."

He had quietly checked Buth"s identification papers and his Imperial Grant, then he"d said casually: "You haven"t seen your home yet, I take it?"

Buth shook his head. "Not directly. Full stereos, of course; it"s quite what I want. I-" He stopped, realizing that he wasn"t making much sense to the young man. He started again: .II really don"t see how I managed to get a place here; think how many must apply each year-hundreds of billions, I suppose."

"About that," agreed Faloban. He opened the door of his ground car. "Hop in," he said. ""I"ll drive you out to your place."

Buth nodded his thanks and stepped carefully inside the little machine. He had to move carefully these days, had to remember that old bones are brittle and old muscles tear easily. "And how many are accepted?" he continued. "Only a few?"

Faloban slid into the driver"s seat. "An average of ten thousand a year," he said. "N ot many are chosen."

"I don"t know what I ever did to deserve it," Buth said.

Faloban chuckled as he trod on the accelerator and the little vehicle slid smoothly out to the road.

"You really great men are all like that. You never think you"ve done anything."

"No, no," said Dr. Buth, "it"s not like that at all. I really never did do anything~ "

Faloban just chuckled again. "You"ll have to talk to your neighbor, old Ducem Palver, on that score. He"s always saying he never did anything, either. Amazing, isn"t it, how the Emperor never picks anyone but ne"er-do-wells?"

But Dr. Nikol Buth wasn"t listening. Ducem Palver, he was thinking, Ducem Palver. Where have I heard that name before?

And then he remembered. Aloud, he said: "Yes, I will have to see Mr. Palver. He"s a near neighbor, you say?" "Just a kilometer away. We"ll go right by his place on the way to your new home," Faloban said.

It was a woman who opened the door, a short, round, pleasant-faced woman whose halo of white hair seemed almost silvery. She was old, yes, but her face still held the beauty of her youth, modified by the decades of life so that it was changed into a graciousness-almost a regal queenliness.

"Yes?" Her voice was soft, and her smile kindly.

"I-" Buth felt the hesitation in his voice and tried to overcome it. "I"m looking for Mr. Ducem Palver. My name is Buth-Dr. Nikol Buth; I...I don"t know if he remembers me, but-"

The woman stood aside. "Come in, Dr. Buth, come in. I"m Mrs. Palver; I"ll see if my husband is busy."