isdifficult, since mental activities are, of necessity, of a higherorder than physical activities.

  Some of the operations of tensor calculus have analogs in algebra;many do not.

  * * * * *

  Taggert gestured with one hand. "He's been in business there foryears. Evidently, he's been able to make a few accurate predictionsnow and then--enough to keep his reputation going. He's tried toincrease the frequency, accuracy, and detail of his 'flashes' bystudying up on the techniques used by other seers, and, as a result,he's managed to soak up enough mystic balderdash to fill a library.

  "He embellishes every one of his predictions to his 'clients' with allkinds of hokum, and he's been doing it so long that he really isn'tsure how much of any prediction is truth and how much is embroiderywork.

  "The boys are trying to get more information on him now, and they'regoing to do a little deep probing, if they can get him set up right;maybe they'll be able to trigger off another flash on thatmoon-hit--but I doubt it."

  Senator Kerotski thumbed his chin morosely. "You're probably right.Apparently, once those hunches come to a precog, they get everythingin a flash and then they can't get another thing--ever. I wish wecould get our hands on one who was halfway along toward _the_ point.We've got experts on psychokinetics, levitation, telepathy,clairvoyance, and what-have-you. But precognition we don't seem to beable to find."

  "We've got one now," Brian Taggert reminded him.

  The senator snorted. "Even assuming that we had any theory onprecognition completely symbolized, and assuming that this Forsythehas the kind of mind that can be taught, do you think we could get itdone in a month? Because that's all the time we have."

  "He's our first case," Taggert admitted. "We'll have to probeeverything out of him and construct symbol-theory around what we get.I'll be surprised if we get anywhere at all in the first six months."

  Senator Kerotski put his hand over his eyes. "I give up. First theChinese Soviet kidnaps Dr. Ch'ien and we have to scramble like maniacsto get him back before they find out that he's building a space drivethat will make the rocket industry obsolete. Then we have to find outwhat's causing the rash of accidents that is holding up Dr. TheodoreNordred's antigravity project. And now, just as everything is comingto a head in both departments, we find that a meteor is going to hitMoonbase One sometime between thirty and sixty days from now." Hespread apart the middle and ring fingers of the hand that covered hiseyes and looked at Taggert through one eye. "And now you tell me thatthe only man who can pinpoint that time more exactly for us is of nouse whatever to us. If we knew when that meteor was due to arrive, wewould be able to spot and deflect it in time. It must be of prettygood size if it's going to demolish the whole base."

  "How do you know it's going to be a meteor?"

  "You think the Soviets would try to bomb it? Don't be silly, Taggert,"Kerotski said, grinning.

  Taggert grinned back. "I'm not thinking they'd bomb us; but I'm tryingto look at all the angles."

  The worried look came back to the senator's pandalike face. "We haveto do something. If only we _knew_ that Forsythe's prediction willreally come off. Or, if it will, then exactly _when_? And is thereanything we can do about it, or will it be like the airline incident.If we hadn't made them switch planes, nothing would have happened.What if, no matter what we do, Moonbase One goes anyway?

  "Remember, we haven't yet built Moonbase Two. If our only base on themoon is destroyed, the Soviets will have the whole moon to themselves.Have you any suggestions?"

  "Sure," said Taggert. "Ask yourself one question: What is the purposeof Moonbase One?"

  Slowly, a beatific smile spread itself over the senator's face.

  The whole discussion had taken exactly ninety seconds.

  * * * * *

  "Mrs. Jesser," said Brian Taggert to the well-rounded, fortyish womanbehind the reception desk at S.M.M.R. headquarters, "this is Dr.Forsythe. He has established a reputation as one of the finest seersliving today."

  Mrs. Jesser looked at the distinguished, white-bearded gentleman withan expression that was almost identical with the one her grandmotherhad worn when she met Rudolph Valentino, nearly sixty years before,and the one her mother had worn when she saw Frank Sinatra ageneration later. It was not an uncommon expression for Mrs. Jesser'sface to wear: it appeared every time she was introduced to anyone wholooked impressive and was touted as a great mystic of one kind oranother.

  "I'm _so_ glad to _meet_ you, Dr. Forsythe!" she burbled eagerly.

  "Dr. Forsythe will be working for us for the next few months--hisoffice will be Room B on the fourth floor," Taggert finished. He wasgenuinely fond of the woman, in spite of her mental dithers andschoolgirl mannerisms. Mysticism fascinated her, and she was firmlyconvinced that she had "just a _weenie_ bit" of psychic power herself,although its exact nature seemed to change from time to time. But shedid both her jobs well, although she was not aware of her doublefunction. She thought she was being paid as a receptionist and phoneoperator, and she was quick and efficient about her work. She was alsothe perfect screen for the Society's real work, for if anyone eversuspected that the S.M.M.R. was not the group of crackpots that itappeared to be, five minutes talking with Mrs. Jesser would convincethem otherwise.

  "Oh, you're _staying_ with us, Dr. Forsythe? How wonderful! We simply_must_ have a talk sometime!"

  "Indeed we must, dear lady," said Forsythe. His voice and manner hadjust the right amount of benign dignity, with an almost indetectabletouch of pompous condescending.

  "Come along, doctor; I'll show you to your office." Taggert's facebetrayed nothing of the enjoyment he was getting out of watching themental gymnastics of the two. Forsythe and Mrs. Jesser were similar insome ways, but, of the two, Mrs. Jesser was actually the more honest.She only fooled herself; she never tried to fool anyone else.Forsythe, on the other hand, tried to put on a front for others, and,in doing so, had managed to delude himself pretty thoroughly.

  Taggert's humor was not malicious; he was not laughing at them. He wasadmiring the skill of the human mind in tying itself in knots. Whenone watches a clever contortionist going through his paces, onedoesn't laugh at the contortionist; one admires and enjoys the weirdtwists he can get himself into. And, like Taggert, one can only feelsympathy for one whose knots have become so devious and intricate thathe can never extricate himself.

  "Just follow me up the stairs," Taggert said. "I'll show you whereyour office is. Sorry we don't have an elevator, but this old buildingjust wasn't built for it, and we've never had any real need for one."

  "Perfectly all right," Forsythe said, following along behind.

  _Three weeks!_

  Taggert had to assume that the minimum time prediction was theaccurate one. Damn! Why couldn't this last prediction have been asprecise as the one about the air flight from Puerto Rico?

  It had taken six days for the "accredited" agents of the S.M.M.R. topersuade Dr. Peter Forsythe that he should leave his little place onthe Boardwalk and come down to Arlington to work. It isn't easy topersuade a man to leave a business that he's built up over a longperiod of years, especially during the busy season. To leave theBoardwalk during the summer would, as far as Forsythe was concerned,be tantamount to economic suicide. He had to be offered not only anincome better than the one he was making, but better security as well.At fifty-four, one does not lightly throw over the work of a lifetime.

  Still, he had plenty of safeguards. The rent was paid on his Boardwalkoffice, he had a guaranteed salary while he was working, and a"research bonus," designed to keep him working until the Society wasfinished with that phase of its work.

  It's rather difficult for a man to resist the salesmanship of atelepath who knows exactly what his customer wants and, better, whathe needs.

  * * * * *

  On the fourth floor, there were sounds of movement, the low staccatochatter of typers, occasional bits of conversation, and the hum ofe
lectronic equipment.

  Forsythe was impressed, though not a line on his face showed it. Theoffice to which he had been assigned was lined with electroniccalculators, and his name had already been put on the door in gold. Itwas to his credit that he was impressed by the two factors in thatorder.

  In the rear of the room, two technicians were working on an open panelin one of the units. Nearby, a dark-haired, dark-eyed, maturelyhandsome woman in her early thirties was holding a clip board andmaking occasional notes as the men worked. One of the men was using anelectric drill, and the whine of metal on metal drowned out the