the building superintendent exchanged a few more pleasantrieswith Turnbull and departed. Turnbull headed back toward the kitchen,picked up his glass of sherry, and sat down in the breakfast nook toread the letters.
The one from Standard Recording had come just a few days after he'dleft, thanking him for notifying them that he wanted to suspend hismembership for a year. The three letters from Cairo, London, and LunaCity were simply chatty little social notes, nothing more.
The three from Scholar Duckworth were from a different breed of cat.
The first was postmarked 21 August 2187, three months after Turnbull hadleft for Lobon. It was neatly addressed to Dave F. Turnbull, Ph.D.
* * * * *
Dear Dave (it read):
I know I haven't been as consistent in keeping up with my old pupils asI ought to have been. For this, I can only beat my breast violently andmutter _mea culpa, mea culpa, mea maxima culpa_. I can't even plead thatI was so immersed in my own work that I hadn't the time to write,because I'm busier right now than I've been for years, and I've had to_make_ time for this letter.
Of course, in another way, this is strictly a business letter, and itdoes pertain to my work, so the time isn't as hard to find as it mightbe.
But don't think I haven't been watching your work. I've read every oneof your articles in the various journals, and I have copies of all fourof your books nestled securely in my library. Columbia should be--andapparently is--proud to have a man of your ability on its staff. At therate you've been going, it won't be long before you get an invitationfrom the Advanced Study Board to study for your Scholar's degree.
As a matter of fact, I'd like to make you an offer right now to do someoriginal research with me. I may not be a top-flight genius likeMetternick or Dahl, but my reputation does carry some weight with theBoard. (_That, Turnbull thought, was a bit of needless modesty;Duckworth wasn't the showman that Metternick was, or the prolific writerthat Dahl was, but he had more intelligence and down-right wisdom thaneither._) So if you could manage to get a few months leave fromColumbia, I'd be honored to have your assistance. (_More modesty,thought Turnbull. The honor would be just the other way round._)
The problem, in case you're wondering, has to do with the CentaurusMystery; I think I've uncovered a new approach that will literally kickthe supports right out from under every theory that's been evolved forthe existence of that city. Sound interesting?
I'm mailing this early, so it should reach you in the late afternoonmail. If you'll be at home between 1900 and 2000, I'll call you and giveyou the details. If you've got a pressing appointment, leave detailswith the operator.
All the best, Jim Duckworth
* * * * *
Turnbull slid the letter back into its tube and picked up the secondletter, dated 22 August 2187, one day later.
* * * * *
Dear Dave,
I called last night, and the operator said your phone has beentemporarily disconnected. I presume these letters will be forwarded, soplease let me know where you are. I'm usually at home between 1800 and2300, so call me collect within the next three or four days.
All the best, Jim
* * * * *
The third letter was dated 10 November 2187. Turnbull wondered why ithad been sent. Obviously, the manager of the Excelsior had sentDuckworth a notice that Dr. Turnbull was off-planet and could not bereached. He must have received the notice on the afternoon of 22 August.That would account for his having sent a second letter before he got thenotice. Then why the third letter?
* * * * *
Dear Dave,
I know you won't be reading this letter for six months or so, but atleast it will tell you where I am. I guess I wasn't keeping as closetabs on your work as I thought: otherwise I would have known about theexpedition to Lobon. You ought to be able to make enough credit on thattrip to bring you to the attention of the Board.
And don't feel too bad about missing my first letters or the call. I wasoff on a wild goose chase that just didn't pan out, so you really didn'tmiss a devil of a lot.
As a matter of fact, it was rather disappointing to me, so I've decidedto take a long-needed sabbatical leave and combine it with a littleresearch on the half-intelligent natives of Mendez. I'll see you in ayear or so.
As ever, Jim Duckworth
* * * * *
Well, that was that, Turnbull thought. It galled him a little to thinkthat he'd been offered a chance to do research with Scholar Duckworthand hadn't been able to take it. But if the research hadn't pannedout.... He frowned and turned back to the first letter.
A theory that would "literally kick the supports right out from underevery theory that's been evolved for the existence of that city," he'dsaid. Odd. It was unlike Duckworth to be so positive about anythinguntil he could support his own theory without much fear of having itpulled to pieces.
Turnbull poured himself a second glass of sherry, took a sip, and rolledit carefully over his tongue.
The Centaurus Mystery. That's what the explorers had called it back in2041, nearly a century and a half before, when they'd found the greatcity on one of the planets of the Alpha Centaurus system. Man's firstinterstellar trip had taken nearly five years at sublight velocities,and _bing!_--right off the bat, they'd found something that madeinterstellar travel worthwhile, even though they'd found no planet inthe Alpha Centaurus system that was really habitable for man.
They'd seen it from space--a huge domed city gleaming like a great gemfrom the center of the huge desert that covered most of the planet. Theplanet itself was Marslike--flat and arid over most of its surface, witha thin atmosphere high in CO_2 and very short on oxygen. The city showedup very well through the cloudless air.
From the very beginning, it had been obvious that whoever or whateverhad built that city had not evolved on the planet where it had beenbuilt. Nothing more complex than the lichens had ever evolved there, asthousands of drillings into the crust of the planet had shown.
Certainly nothing of near-humanoid construction could ever have comeinto being on that planet without leaving some trace of themselves ortheir genetic forebears except for that single huge city.
How long the city had been there was anyone's guess. A thousand years? Amillion? There was no way of telling. It had been sealed tightly, sonone of the sand that blew across the planet's surface could get in. Ithad been set on a high plateau of rock, far enough above the desertlevel to keep it from being buried, and the transparent dome was made ofan aluminum oxide glass that was hard enough to resist the slighterosion of its surface that might have been caused by the gentle, thinwinds dashing microscopic particles of sand against its smooth surface.
Inside, the dry air had preserved nearly every artifact, leaving them asthey had been when the city was deserted by its inhabitants at anunknown time in the past.
That's right--deserted. There were no signs of any remains of livingthings. They'd all simply packed up and left, leaving everything behind.
Dating by the radiocarbon method was useless. Some of the carboncompounds in the various artifacts showed a faint trace of radiocarbon,others showed none. But since the method depends on a knowledge of theamount of nitrogen in the atmosphere of the planet of origin, the rateof bombardment of that atmosphere by high-velocity particles, andseveral other factors, the information on the radioactivity of thespecimens meant nothing. There was also the likelihood that the carbonin the various polymer resins came from oil or coal, and fossil carbonis useless for radio-dating.
Nor did any of the more modern methods show any greater success.
It had taken Man centuries of careful comparison and cross-checking toread the evolutionary history written in the depths of his own planet'scrust--to try to date the city was impossible. It was like trying toguess the time by looking at a facel
ess clock with no hands.
There the city stood--a hundred miles across, ten thousand square milesof complex enigma.
It had given Man his first step into the ever-widening field of CulturalXenology.
Dave Turnbull finished his sherry, got up from the breakfast nook, andwalked into the living room, where his reference books were shelved. Thecopy of Kleistmeistenoppolous' "City of Centaurus" hadn't been opened inyears, but he took it down and flipped it open to within three pages ofthe section he was looking for.
"It is obvious, therefore, that every one of the indicatorspoints in the same direction. The City was not--_could not havebeen_--self-supporting. There is no source of organic material on theplanet great enough to support such a city; therefore, foodstuffs musthave been imported. On the other hand, it is necessary to postulate_some_ reason for establishing a city on an otherwise barren planet