The Machine That Saved The World Part 7

"Look!" he snapped. "We were broadcastin' their trick wave--the wave they used to talk to us! And they picked it up! But they weren't expectin' it! They were set to pick up the wave they told us to transmit! See? That guy'll come back. He's got to! So we got to play along! He'll want to find out if we got wise and won't broadcast ourselves to death! If he finds out we know what we're doin', they'll parachute a transmitter down on us before we can do it to them! Back me up! Get set!"

He removed his hand from the microphone.

"Callin' 2180!" he chattered urgently. "Calling the guy that just contacted us! Come in, 2180! You're not the guy we've been talking to, but come in! Come in, 2180!"

Howell said stridently:

"But if that's 2180, how'd we parachute--".

Lecky clapped a hand over his mouth with a fierceness surprising in so small a man. He whispered desperately into Howell's ear. Graves absurdly began to bite his nails, staring at the communicator-screen. Sergeant Bellews continued his calling, ever more urgently.

His voice echoed peculiarly in the Rehab Shop. It seemed suddenly a place of resonant echoes. All the waiting, repaired, or to-be-rehabilitated machines appeared to listen with interest while Sergeant Bellews called:

"Come in, 2180! We been trying to reach you for a coupla weeks! We got somebody else instead of you, and they been talkin' to us, and they say that they're 3020 instead of 2180, but we've got to contact you! They don't know anything about that germ that's gonna mutate and b.u.mp us off!

It's ancient history to them. We got to reach you! Come in, 2180!"

The flickering yellow lights of the machines wavered as if all the quasi-living machines were listening absorbedly. The Rehab Shop was full of shadows. And Sergeant Bellews sat before the dark-screened communicator with sweat on his face, calling cajolingly to nothingness to come in.

After five minutes the screen grew abruptly bright again. The brisk, raceless broadcaster of the earlier broadcast--not the bearded man--came back. He forced a smile:

"_Ah! 1972! At last you reach us! But we did not hope you could make your transmitters so soon!_"

"We tried to a.n.a.lyze your wave," said Sergeant Bellews, with every appearance of feverish relief, "but we only got it approximate. We tried callin' back with what we got, and we got through time, all right, but we contacted some guys in 3020 instead of you! We need to talk to you!--Can you give me the stuff about that bug that's gonna wipe out half of us? Quick? I got a recorder goin'."

The completely uncharacterizable man in the screen forced a second smile. He held something to his ear. It would be a tiny sound-receiver.

Obviously the contact in time or place or nowhere was being viewed by others than the one man who appeared. He was receiving instructions.

"_Ah!_" he said brightly, "_but now that you have the contact, you will not lose it again! Leave your controls where they are, and our learned men will tell your learned men all that they need to know. But--3020?

You contacted 3020? That is not in our records of your time!_"

He listened again to the thing at his ear. His expression became suddenly suspicious, as if someone had ordered that as well as the words which came next.

"_We do not understand how you could contact a time a thousand years beyond us. It is possible that you attempt a joke. A--a kid, as you would say._"

Sergeant Bellews beamed into the screen which so remarkably functioned as a transmitting-eye also.

"h.e.l.l!" he said cordially. "You know we wouldn't kid you! You or our great-great-great-grandchildren! We depend on you! We got to get you to tell us how not to get wiped out! In 3020 the whole business is forgotten. It's a thousand years old, to them! But they're pa.s.sin' back some swell machinery--"

He turned his head as if listening to something the microphone could not pick up. But he looked appealingly at Lecky. Lecky nodded and moved toward the communicator.

"Look!" said Sergeant Bellews into the screen. "Here's Doc Lecky--one of our top guys. You talk to him."

He gave his seat to Lecky. Out of range of the communicator, he mopped his face. His s.h.i.+rt was soaked through by the sweat produced by the stress of the past few minutes. He s.h.i.+vered violently, and then clamped his teeth and fumbled out sheets of paper. He beckoned to Graves. Graves came.

"We--we got to give him a doctored circuit," whispered Sergeant Bellews desperately, "and it's got to be good--an' quick!"

Graves bent over the paper on which the sergeant dripped sweat. The sergeant murmured through now-chattering teeth what had to be devised, and at once. It must be the circuit-diagram for a transmitter to be given to the man whose face filled the screen. The transmitter must be of at least twenty-kilowatt power. It must be such a circuit as n.o.body had ever seen before.

It must be convincing. It should appear to radiate impossibly, or to destroy energy without radiation. But it must actually produce a broadcast signal of this exotic type--here the sergeant described with shaky precision the exact constants of the wave to be generated--and the broadcaster from nowhere must not be able to deduce those constants or that wave-type from the diagram until he had built the transmitter and tried it.

"I know it can't be done!" said the sergeant desperately. "I know it can't! But it's gotta be! Or they'll parachute a transmitter down on us sure."

Graves smiled a quick and nervous smile. He began to sketch a circuit.

It was a wonderful thing. It was the product of much ingenuity and meditation. It had been devised--by himself--as a brain-teaser for the amus.e.m.e.nt of other high-level scientific brains. Mathematicians zestfully contrive problems to stump each other. Specialists in the higher branches of electronics sometimes present each other with diagrammed circuits which pretend to achieve the impossible. The problem is to find the hidden flaw.

Graves deftly outlined his circuit and began to fill in the details.

Ostensibly, it was a circuit which consumed energy and produced nothing--not even heat. In a sense it was the exact opposite of a perpetual-motion scheme, which pretends to get energy from nowhere. This circuit pretended to radiate energy to nowhere, and yet to get rid of it.

Presently Lecky could be heard expostulating gently:

"But of course we are willing to give you the circuit by which we communicate with the year 3020! Naturally! But it seems strange that you suspect us! After all, if you do not tell us how to meet the danger your broadcasts have told of, you will never be born!"

Sergeant Bellews mopped his face and moved into the screen's field of vision.

"Doc," he said, laying a hand on Lecky's arm. "Doc Graves is sketchin'

what they want right now. You want to come show it, Doc?"

Graves took Lecky's place. He spread out the diagram, finis.h.i.+ng it as he talked. His nervous, faint smile appeared as the mannerism of embarra.s.sment it was.

"There can be no radiation from a coil shaped like this," he said embarra.s.sedly, "because of the Werner Principle.... Yet on examination ... input to the transistor series involves ... energy must flow ...

and when this coil...."

His voice flowed on. He explained a puzzle, presenting it diffidently as he had presented it to other men in his own field. Then he had been playing--for fun. Now he played for perhaps the highest stakes that could be imagined.

He completed his diagram and, smiling nervously, held it up to the communicator-screen. It was instantly transmitted, of course. To nowhere. Which was most appropriate, because it pretended to be the diagram of a circuit sending radiation to the same place.

The face on the screen twitched, now. The hand with the tiny earphone was always at the ear of the man on the screen, so that he plainly did not speak one word without high authority.

"_We will--examine this_," he said. His voice was a full two tones higher than it had been. "_If you have been--truthful we will give you the information you wish_."

_Click!_ The screen went dark. Lecky let out his breath. Sergeant Bellews threw off the transmission switch. He began to shake. Howell said indignantly:

"When I make a mistake, I admit it! That broadcast isn't from the future! If it hadn't been a lie, he'd have known he had to tell us what we wanted to know! He couldn't hold us up for terms! If he let us die he wouldn't exist!"

"Y-yeah," said Sergeant Bellews. "What I'm wonderin' is, did we fool him?"

"Oh, yes!" said Graves, with diffident confidence. "I don't know but three men in the world who could find the flaw in that circuit." He smiled faintly. "But it radiates all the energy that's fed into it." He turned to Sergeant Bellews. "You gave me the constants of a wave you wanted it to radiate. I fixed it. It will. But why that special type--that special wave?"

Sergeant Bellews pulled himself together.