sodium, cadmium, so on.”
“Harla says go on.”
“Now we make an electrolyte. Preferably an alkaline salt.”
“Be careful,” I said. “Or you’ll be asking Harla to identify stuff from a litmus paper.”
“No,” said Lou. He faced Teresa and said, “An alkaline substance burns the flesh badly.”
“So do acids,” I objected.
“Alkaline substances are found in nature,” he reminded me. “Acids aren’t often natural. The point is that an acid will work. Even salt water will work. But an alkaline salt works better. At any rate, tell Harla that the stuff, like zinc, was known to civilized peoples many centuries before chemistry became a science. Acids, on the other hand, are fairly recent.”
“Harla understands.”
“Now,” said Lou Graham triumphantly, “we make our battery by immersing the carbon and the zinc in the electrolyte. The carbon is the positive electrode and should be connected to the start of our electromagnet, whereas the end of the winding must go to the zinc. This will place the north pole to the left hand.”
“Harla understands,” said Teresa. “So far, Harla can perform this experiment in his mind. But now we must identify which end of the steel bar is north-pole magnetic.”
“If we make the bar magnetic and then immerse it in acid, the north magnetic pole will be selectively etched.”
“Harla says that this he does not know about. He has never heard of it, although he is quite familiar with electromagnets, batteries, and the like.”
I looked at Lou Graham. “Did you cook this out of your head, or did you use a handbook?”
He looked downcast. “I did use a handbook,” he admitted. “But—”
“Lou,” I said unhappily, “I’ve never said that we couldn’t establish a common frame of reference. What we lack is one that can be established in minutes. Something physical—” I stopped short as a shadowy thought began to form.
*
Paul Wallach looked at me as though he’d like to speak but didn’t want to interrupt my train of thoughts. When he could contain himself no longer, he said, “Out with it, Tom.”
“Maybe,” I muttered. “Surely there must be something physical.”
“How so?”
“The tunnel car must be full of it,” I said. “Screws?”
I turned to Saul Graben. Saul is our mechanical genius; give him a sketch made on used Kleenex with a blunt lipstick and he will bring you back a gleaming mechanism that runs like a hundred-dollar wrist watch.
But not this time. Saul shook his head.
“What’s permanent is welded and what’s temporary is snapped in with plug buttons,” he said.
“Good Lord,” I said. “There simply must be something!”
“There probably is,” said Saul. “But this Harla chap would have to use an acetylene torch to get at it.”
I turned to Teresa. “Can this psi-man Harla penetrate metal?”
“Can anyone?” she replied quietly.
Wallach touched my arm. “You’re making the standard, erroneous assumption that a sense of perception will give its owner a blueprint-clear grasp of the mechanical details of some machinery. It doesn’t. Perception, as I understand it, is not even similar to eyesight.”
“But—” I fumbled on—“surely there must be some common reference there, even granting that perception isn’t eyesight. So how does perception work?”
“Tom, if you were blind from birth, I could tell you that I have eyesight that permits me to see the details of things that you can determine only by feeling them. This you might understand basically. But you could never be made to understand the true definition of the word ‘picture’ nor grasp the mental impression that is generated by eyesight.”
“Well,” I persisted, “can he penetrate flesh?”
“Flesh?”
“Holly’s heart has stopped,” I said. “But it hasn’t been removed. If Harla can perceive through human flesh, he might be able to perceive the large, single organ in the chest cavity near the spine.”
Teresa said, “Harla’s perception gives him a blurry, incomplete impression.” She looked at me. “It is something like a badly out-of-focus, grossly under-exposed x-ray solid.”
“X-ray solid?” I asked.
“It’s the closest thing that you might be able to understand,” she said lamely.
I dropped it right there. Teresa had probably been groping in the dark for some simile that would convey the nearest possible impression. I felt that this was going to be the nearest that I would ever get to understanding the sense of perception.
“Can’t he get a clear view?”
“He has not the right.”
“Right!” I exploded. “Why—”
Wallach held up his hand to stop me. “Don’t make Teresa fumble for words, Tom. Harla has not the right to invade the person of Holly Carter. Therefore he can not get a clearer perception of her insides.”
“Hell!” I roared. “Give Harla the right.”
“No one has authority.”
“Authority be dammed!” I bellowed angrily. “That girl’s life is at stake!”
*
Wallach nodded unhappily. “Were this a medical emergency, a surgeon might close his eyes to the laws that require authorization to operate. But even if he saved the patient’s life, he is laying himself open to a lawsuit. But this is different, Tom. As you may know, the ability of any psi-person is measured by their welcome to the information. Thus Teresa and Harla, both willing to communicate, are able.”
“But can’t Harla understand that the entire bunch of us are willing that he should take a peek?”
“Confound it, Tom, it isn’t a matter of our permission! It’s a matter of fact. It would ease things if Holly were married to one of us, but even so it wouldn’t be entirely clear. It has to do with the invasion of privacy.”
“Privacy? In this case the very idea is ridiculous.”
“Maybe so,” said Paul Wallach. “But I don’t make the rules. They’re natural laws. As immutable as the laws of gravity or the refraction of light. And Tom, even if I were making the laws I might not change things. Not even to save Holly Carter’s life. Because, Tom, if telepathy and perception were as free and unbounded as some of their early proponents claimed, life would
