Very curious results turned up as a consequence of enthusiastic but uninformed putterings with Grek machinery. A new laser principle turned up in a high school science laboratory and burned down half a high school before it could be gotten under control. Somebody else bewilderedly displayed something which could only be described as the fractional distillation of isotopes. Such things were admirable, but they didn't apply to the big problem on which the fate of humanity depended.
Even Hackett puttered fretfully in the woodshed of Lucy's Cousin Constance. He resented the unscientific methods he was using, but there was no scientific way to attack the problem. The human race had to have one thing if it was to have any hope of resisting the Greks. It had to have power that the Greks couldn't turn off. Human generating plants were abandoned and power distribution networks were gone down the drain for lack of maintainance. The Greks could cut off three-quarters of the world's power supply at will. We humans didn't even know where it was generated!
So Hackett puttered. He searched harassedly and almost at random for some portion of some Grek device that wouldn't look like itself—itself being a way to get power out of anything at all. We know now that his whole notion was wrong, but the odds were astronomically against us anyhow.
And naturally, at just this time a more than usually depressing development would have to appear. Hackett had been one of those to insist that the skies ought to be watched more carefully. Apparatus had been improvised. Wide-angle Schmidt telescopes were set to work forming temperature images of the sky. Johnson detectors scanned the images for spots whose temperature was above normal for the background.
They picked up a moving higher temperature area almost at the edge of the moon and actually just as it came out from behind it. It did not reflect sunlight. No telescope could pick it up, but it could be tracked. Something warmer than interplanetary space moved toward Earth from the moon. It was radar black.
Johnson detectors trailed it to a halt some thousands of miles out from the arctic regions. It hovered there as if making certain no new strange frequency played upon it.
It descended. No human eye saw it, but the detectors that amplified infra-red as if it were microwaves triangulated its descent. It stayed aground for some days, then rose once more and went around the bulge of the Earth, down the middle of the Pacific. There were jet planes racing it to the antarctic, but they lost. They had Johnson detectors, however, at work when it rose once more and went deliberately back to the moon. There were guesses that since signals from the moon had been picked up by men, physical communication was desirable for the time being.
Then Hackett discovered that a curiously formed small metal part in the Aldarian hearing aid looked very much like a larger part in a broadcast-power receiver. It was a fishlike shape, extraordinarily resembling one of the figures in the Tao, the Chinese symbol of the eternal way. In the power-receiver it performed a function, carrying current from one place to another. Its peculiar shape allowed it to do so without shorting anything. In the Aldarian device the piece of metal was smaller—much smaller—but was identical in shape except at the pointed end. There the two elements of the two devices differed markedly. That pointed end was the spot where the broadcast receiver appeared to deliver usable current. And the force-field of the Aldarian device, the energy-field, the whatever-it-was that affected severed nerves, appeared to come into existence at the corresponding differently shaped pointed end.
Lucy watched as he sweated over the cryptic, comparable parts. She acted oddly, these days. She seemed relieved when he straightened up, shaking his head helplessly.
"It takes power from nowhere," he said, "but we almost understand that. Then the same power—it must be the same power—comes out of the apparatus in the one case as something that affects only cut nerves, and in the other it's perfectly normal high-frequency current we can rectify and use!"
Lucy watched his face. She said tentatively, "Nerves are pretty much alike in some ways, as electric conductors are. Stimulate an optic nerve by any means and you see a flash of fight. Give the same stimulus to a taste bud and you have taste. Pain nerves will report pain from the same stimulus that reported as fight, taste, and so on. It's not the stimulus given to a nerve or a wire that determines what happens. It's what the nerve or wire leads to."
He looked up at her blankly. Then his eyes grew shrewd.
"Go on!"
"Go on with what?" asked Lucy.
"You've got the answer I haven't found," said Hackett. "I think you've had it for some time. I can't find it—tell me."
Lucy hesitated.
"Come on!" he insisted. "Come on! You try to keep me from realizing how many brains you have, but you aren't smart enough. You can't fool me on a thing like this. I can read you like a book."
"You can? I don't think so!"
"You were hinting at the answer then. You were trying to make me think of something that's all clear in your own mind." He grinned suddenly. "Do that, Lucy, and I'll prove I can read you like a book!"
She looked at him for a long time, studying his expression.
"It isn't all clear," she said defensively, and untruthfully. "But that piece of metal could be, for most of its length, like a nerve. Broadcast power—whatever that is!—goes into the thick rounded end of it. But the thin ends are shaped differently in the two instruments, and they don't need to be if they're only current carriers. I said that one nerve makes a sensation of light and another of pain and so on, depending on what it goes to."
"So?" said Hackett.
"I wonder," said Lucy reluctantly, "if you made a new small piece to fit in the hearing aid, and shaped it like the piece from the power receiver—I wonder if it would turn the hearing aid into a power receiver?"
Hackett's grin went awry. He shook his head and stood up.
"You mean," he told her, "that the shape in general transforms the broadcast power—whatever it is—but the shape of the thin end determines what it's transformed into." Then he said vexedly, "I'm the damnedest idiot, Lucy—"
He reached out his hands and drew her to him. He kissed her thoroughly. For an instant she resisted, then she didn't.
"I'm a damned idiot for not doing that before," he said a moment later.
"N-no," said Lucy, rather breathless. "But when you did that, you—did read me like a book!"
"We'll prove that you're right about the gadget," said Hackett, "after one more short paragraph."
Presently they were smiling at each other quite absurdly. Hackett said, "It seemed there wasn't any use in anything, Lucy. I didn't want to be sure about you because I thought this business of the Greks was hopeless. And if it was, I meant to get killed because—"
"We'll win now," said Lucy confidently.
"Now," he told her, "we've got to! Stay here and watch while I prove how beautifully your idea works. It's going to make all the difference in the world."
It took him all of half an hour to make a minute, curled up, fish-shaped sliver of metal perhaps three-quarters of an inch long. It was exactly like the one in the Aldarian device except for the last sixteenth of an inch. There its shape was that of the corresponding part of the power receiver.
He assembled it into the tiny, watch-shaped object. He moved the stud.
There was the smell of hot metal. The device that had formerly affected severed nerves no longer did anything of the sort. Instead, it took broadcast power from somewhere and turned out electric current enough to melt itself down if Hackett hadn't hastily turned it off.