It was the first sentence he had spoken in the past hour or so, and it was purely for the edification of the man who was standing on the other side of the air lock, although neither Griffin nor MacHeath had actually seen him as yet.

Griffin was not a telepath in the sense that the S.M.M.R. used the word, but to a non-psionicist, he would have appeared to be one.

Membership in the "core" group of the _Society for Mystical and Metaphysical Research_ required, above all, _understanding_. And, with that understanding, a conversation between two members need consist only of an occasional gesture and a key word now and then.

The word "understanding" needs emphasis. Without understanding of another human mind, no human mind can be completely effective. Without that understanding, no human being can be completely free.

And yet, the English word "understanding" is only an approximation to the actual process that must take place. _Total_ understanding, in one sense, would require that a person actually _become_ another person--that he be able to feel, completely and absolutely, every emotion, every thought, every bodily sensation, every twinge of memory, every judgment, every decision, and every sense of personal ident.i.ty that is felt by the other person, no more and no less.

Such totality is, obviously, neither attainable nor desirable. The result would be a merger of ident.i.ties, a total unification. And, as a consequence, a complete loss of one of the human beings involved.

Optimum "understanding" requires that a judgment be made, and that, in turn, requires _two_ minds--not a fusion of ident.i.ty. There must be one to judge and another to be judged, and each mind plays both roles.

_Love thy neighbor as thyself._ But the original Greek word would translate better as "respect and understand" than as the modern English "love." The founders of our modern religions were not fools; they simply did not have the tools at hand to formulate their knowledge properly. As understanding increases, a critical point is reached, which causes a qualitative change in the human mind.

First, self-understanding must come. The human mind operates through similarities, and the thing most similar to any human mind is itself.

The next most similar thing is another human mind.

From that point on, all objects, processes, and patterns in the universe can be graded according to their similarity to each other, and, ultimately, to their similarity to the human mind.

Two given ent.i.ties may seem utterly dissimilar, but they can always be linked by a _tertium quid_--a "third thing" which is similar to both.

This third thing, be it a material object or a product of the human imagination, is called a symbol. Symbols are the bridges by which the human mind can reach and manipulate the universe in which it exists.

With the proper symbols and the understanding to use them, the human mind is limited only by its own inherent structural restrictions.

One of the most active research projects of the S.M.M.R. was the construction of a more powerful symbology. Psionics had made tremendous strides in the previous four decades, but it was still in the alchemy stage. So far, symbols for various processes could only be worked out by cut-and-try, rule-of-thumb methods, using symbols already established, including languages and mathematics. None were completely satisfactory, but they worked fairly well within their narrow limits.

As far as communication was concerned, the hashed-together symbology used by the S.M.M.R. was better than any conceivable code. The understanding required to "break" the "code" was well beyond the critical point. Anyone who could break it was, _ipso facto_, a member of the S.M.M.R.

Most people didn't even realize that a conversation was taking place between two members, especially if a "cover conversation" was used at the same time.

MacHeath's verbal discussion of the testing of the nuclei accelerator was just such a cover. Even before he had cracked the air lock, he had known that Dr. Theodore Nordred was standing on the other side of the thick wall.

MacHeath pushed the heavy door open on its smooth hinges. "Oh, h.e.l.lo, Dr. Nordred. How's everything?"

The heavy-set mathematician smiled pleasantly as MacHeath and Griffin came into the gun chamber. "I just thought I'd come down and see how you were getting along," he said. His voice was a low tenor, with just a touch of Midwestern tw.a.n.g. "Sometimes the creative mind gets bogged down in the nth-order abstractions that have no discernible connection with anything at all." He chuckled. "When that happens, I drop everything and go out to find something mundane to worry about."

Nordred was only an inch shorter than the slim MacHeath, and he weighed in at close to two hundred pounds. At twenty-five, he had had the build of a lightweight wrestler; thirty more years had added poundage--a roll beneath his chin and a bulge at the belly--but he still looked capable of going a round or two without tiring. His shock of heavy hair was a mixture of mouse-brown and gray, and it seemed to have a tendency to stand up on end, which added another inch and a half to his height. His round face had a tendency to smile when he was talking or working with his hands; when he was deep in thought, his face usually relaxed into thoughtful blankness. He frowned rarely, and only for seconds at a time.

"It seems to me you have enough to worry about, doctor," MacHeath said banteringly, "without looking for it." He put down his instrument case and took out a cigarette while Griffin closed the door to the acceleration tube.

"Oh I don't have to look far," Nordred said. "How long do you think it will be before we can resume our work with the Monster?"

"Ten days to two weeks," MacHeath said promptly.

"I see." One his rare frowns crossed his face. "I wish I knew why the exciter arced across. It shouldn't have."

"Don't you have any idea?" MacHeath asked innocently. At the same time, he opened his mind wide to net in every wisp and filament of Nordred's thoughts that he could reach.

"None at all," admitted the mathematician. "Weakness in the insulation, I suppose, though it tested solidly enough." And his mind, as far back as his preconscious and the upper fringes of his subconscious, agreed with his words. MacHeath could go no deeper as yet; he didn't know Nordred well enough yet.

There were suspicions in Nordred's mind that the insulation weakness must have been caused by deliberate sabotage, but he had no one to pin his suspicions on. Neither he nor anyone else connected with the Redford project was aware of the true status of Dr. Konrad Bern.

"Well, let's hope it doesn't happen again," MacHeath said. "Balancing these babies so that they work properly is hard enough for a deuteron accelerator, but the Monster here is ten times as touchy."

Nordred nodded absently. "I know. But our work can't be done with anything less." Nordred actually knew less about the engineering details of the big accelerator than anyone else on the project; he was primarily a philosopher-mathematician, and only secondarily a physicist. He was theoretically in charge of the project, but the actual experimentation was done by the other four men; Drs. Roger Kent, Paul Luvochek, Solomon Bessermann, and Konrad Bern. These four and their a.s.sistants set up and ran off the experiments designed to test Dr. Nordred's theories.

MacHeath picked up his instrument case again, and the three men went out of the gun chamber, into the outer room, and then started up the spiral stairway that led to the surface, talking as they went. But the apparent conversation had little to do with the instruction that MacHeath was giving Griffin as they climbed.

So when MacHeath stopped suddenly and patted at his coverall pockets, Griffin was ready for the words that came next.

"d.a.m.n!" MacHeath said. "I've left my notebook. Will you go down and get it for me, Bill?"

Dr. Nordred had neither understood nor noticed the actual instructions:

"Bill, as soon as I give you an excuse, get back down there and check that gun chamber. Give it a thorough going-over. I don't really think you'll find a thing, but I don't want to take any chances at this stage of the game."

"Right," said Griffin, starting back down the stairway.

MacHeath and Dr. Nordred went on climbing.

David MacHeath sat at a table in the project's cafeteria, absently stirring his coffee, and trying to look professionally modest while Dr. Luvochek and Dr. Bessermann alternately praised him for his work.

Luvochek, a tubby little b.u.t.terball of a man, whose cherubic face would have made him look almost childlike if it weren't for the blue of his jaw, said: "You and those two men of yours have really done a marvelous job in the past four days, Mr. MacHeath--really marvelous."

"I'll say," Bessermann chimed in. "I was getting pretty tired of looking at burned-out equipment and spending three-quarters of my time putting in replacement parts and wielding a soldering gun." Bessermann was leaner than Luvochek, but, like his brother scientist, he was balding on top. Both men were in their middle thirties.

"I don't understand this jinx, myself," Luvochek said. "At first, it was just little things, but the accidents got worse and worse. And then, when the Monster blew--" He stopped and shook his head slowly.

"I'd suspect sabotage, except that there was never any sign of tampering with the equipment I saw."

"What do you think of the sabotage idea?" Bessermann asked MacHeath.

MacHeath shrugged. "Haven't seen any signs of it."

"Run of bad luck," said Luvochek. "That's all."

As they talked MacHeath absorbed the patterns of thought that wove in and out in the two men's minds. Both men were more open than Dr.

Nordred; they were easier for MacHeath to understand. Nowhere was there any thought of guilt--at least, as far as sabotage was concerned.

MacHeath drank his coffee slowly and thoughtfully, keeping up his part of the three-way conversation while he concentrated on his own problem.

One thing was certain: Nowhere in the minds of any of the personnel of the Redford Project was there any conscious knowledge of sabotage. Not even in the mind of Konrad Bern.

Dr. Roger Kent, a tall, lantern-jawed sad-eyed man in his forties, had been hard to get through to at first, but as soon as MacHeath discovered that the hard block Kent had built up around himself was caused by grief over a wife who had been dead five years, he became as easy to read as a billboard. Kent had submerged his grief in work; the eternal drive of the true scientist to drag the truth out of Mother Nature. He was const.i.tutionally incapable of sabotaging the very instruments that had been built to dig in after that truth.