The Machine That Saved The World

: The Machine That Saved The World

They were broadcasts from nowhere--sinister emanations flooding in from

space--smashing any receiver that picked them up. What defense could

Earth devise against science such as this?



The first broadcast came in 1972, while Mahon-modified machines were

still strictly classified, and the world had heard only rumors about

them. The first broadcast was picked up by a television ham in Osceola,

Florida, who f
mingly reported artificial interference on the amateur TV

bands. He heard and taped it for ten minutes--so he said--before it blew

out his receiver. When he replaced the broken element, the broadcast was

gone.



But the Communications Commission looked at and listened to the tape and

practically went through the ceiling. It stationed a monitor truck in

Osceola for months, listening feverishly to nothing.



Then for a long while there were rumors of broadcasts which blew out

receiving apparatus, but nothing definite. Weird patterns appeared on

screens high-pitched or deep-bass notes sounded--and the receiver went

out of operation. After the ham operator in Osceola, nobody else got

more than a second or two of the weird interference before blowing his

set during six very full months of CC agitation.



Then a TV station in Seattle abruptly broadcast interference

superimposed on its regular network program. The screens of all sets

tuned to that program suddenly showed exotic, curiously curved,

meaningless patterns on top of a commercial spectacular broadcast. At

the same time incredible chirping noises came from the speakers,

alternating with deep-bass hootings, which spoiled the ju-ju music of

the most expensive ju-ju band on the air. The interference ended only

with a minor break-down in the transmitting station. It was the same

sort of interference that the Communications Commission had thrown fits

about in Washington. It threw further fits now.



* * * * *



A month later a vision-phone circuit between Chicago and Los Angeles was

unusable for ten minutes. The same meaningless picture-pattern and the

same preposterous noises came on and monopolized the line. It ceased

when a repeater-tube went out and a parallel circuit took over. Again,

frantic agitation displayed by high authority.



Then the interference began to appear more frequently, though still

capriciously. Once a Presidential broadcast was confused by interference

apparently originating in the White House, and again a three-way

top-secret conference between the commanding officers of three military

departments ceased when the unhuman-sounding noises and the scrambled

picture pattern inserted itself into the closed-circuit discussion. The

conference broke up amid consternation. For one reason, military

circuits were supposed to be interference-proof. For another, it

appeared that if interference could be spotted to this circuit or this

receiver it was likely this circuit or that receiver could be tapped.



For a third reason, the broadcasts were dynamite. As received, they

were badly scrambled, but they could be straightened out. Even the first

one, from Osceola, was cleaned up and understood. Enough so to make top

authority tear its hair and allow only fully-cleared scientific

consultants in on the thing.



The content of the broadcasts was kept considerably more secret than the

existence of Mahon units and what they could do. And Mahon units were

brand-new, then, and being worked with only at one research installation

in the United States.



The broadcasts were not so closely confined. The same wriggly patterns

and alien noises were picked up in Montevideo, in Australia, in Panama

City, and in grimly embattled England. All the newspapers discussed them

without ever suspecting that they had been translated into plain speech.

They were featured as freak news--and each new account mentioned that

the broadcast reception had ended with a break-down of the receiving

apparatus.



Guarded messages passed among the high authorities of the nations that

picked up the stuff. A cautious inquiry went even to the Compubs.



The Union of Communist Republics answered characteristically. It asked a

question about Mahon units. There were rumors, it said, about a new

principle of machine-control lately developed in the United States. It

was said that machines equipped with the new units did not wear out,

that they exercised seeming intelligence at their tasks, and that they

promised to end the enormous drain on natural resources caused by the

wearing-out and using-up of standard-type machinery.



The Compub Information Office offered to trade data on the broadcasts

for data about the new Mahon-modified machines. It hinted at extremely

important revelations it could make.



The rest of the world deduced astutely that the Compubs were scared,

too. And they were correct.



* * * * *



Then, quite suddenly, a break came. All previous broadcast receptions

had ended with the break-down of the receiving instrument. Now a

communicator named Betsy, modified in the Mahon manner and at work in

the research installation working with Mahon-modified devices, began to

pick up the broadcasts consistently, keeping each one on its screen

until it ended.



Day after day, at highly irregular intervals, Betsy's screen lighted up

and showed the weird patterns, and her loudspeakers emitted the peepings

and chirps and deep-bass hootings of the broadcasts. And the high brass

went into a dither to end all dithers as tapes of the received material

reached the Pentagon and were translated into intelligible speech and

pictures.



* * * * *



This was when Metech Sergeant Bellews, in charge of the Rehab Shop at

Research Installation 83, came into the affair. Specifically, he entered

the picture when a young second lieutenant came to the shop to fetch him

to Communications Center in that post.



The lieutenant was young and tall and very military. Sergeant Bellews

was not. So he snorted, upon receipt of the message. He was at work on a

vacuum cleaner at the moment--a Mahon-modified machine with a flickering

yellow standby light that wavered between brightness and dimness with

much more than appropriate frequency. The Rehabilitation Shop was where

Mahon-modified machines were brought back to usefulness when somebody

messed them up. Two or three machines--an electric ironer, for

one--operated slowly and hesitantly. That was occupational therapy. A

washing-machine churned briskly, which was convalescence. Others,

ranging from fire-control computers to teletypes and automatic lathes,

simply waited with their standby lights flickering meditatively

according to the manner and custom of Mahon-modified machines. They were

ready for duty again.



The young lieutenant was politely urgent.



"But I been there!" protested Sergeant Bellews. "I checked! It's a

communicator I named Betsy. She's all right! She's been mishandled by

the kinda halfwits Communications has around, but she's a good,

well-balanced, experienced machine. If she's turning out broadcasts,

it's because they're comin' in! She's all right!"



"I know," said the young lieutenant soothingly. His uniform and his

manners were beautiful to behold. "But the Colonel wants you there for a

conference."



"I got a communicator in the shop here," said Sergeant Bellews

suspiciously. "Why don't he call me?"



"Because he wants to try some new adjustments on--ah--Betsy, Sergeant.

You have a way with Mahon machines. They'll do things for you they won't

do for anybody else."



Sergeant Bellews snorted again. He knew he was being buttered up, but

he'd asked for it. He even insisted on it, for the glory of the

Metallurgical Technicians' Corps. The big brass tended to regard Metechs

as in some fashion successors to the long-vanished veterinary surgeons

of the Farriers' Corps, when horses were a part of the armed forces.

Mahon-modified machines were new--very new--but the top brass naturally

remembered everything faintly analogous and applied it all wrong. So

Sergeant Bellews conducted a one-man campaign to establish the dignity

of his profession.



But nobody without special Metech training ought to tinker with a

Mahon-modified machine.



"If he's gonna fool with Betsy," said the Sergeant bitterly, "I guess I

gotta go over an' boss the job."



He pressed a button on his work-table. The vacuum cleaner's standby

light calmed down. The button provided soothing sub-threshold stimuli to

the Mahon unit, not quite giving it the illusion of operating

perfectly--if a Mahon unit could be said to be capable of illusion--but

maintaining it in the rest condition which was the foundation of

Mahon-unit operation, since a Mahon machine must never be turned off.



The lieutenant started out of the door. Sergeant Bellews followed at

leisure. He painstakingly avoided ever walking the regulation two paces

behind a commissioned officer. Either he walked side by side, chatting,

or he walked alone. Wise officers let him get away with it.



* * * * *



Reaching the open air a good twenty yards behind the lieutenant, he

cocked an approving eye at a police-up unit at work on the lawn outside.

Only a couple of weeks before, that unit had been in a bad way. It

stopped and shivered when it encountered an unfamiliar object.



But now it rolled across the grass from one path-edge to another. When

it reached the second path it stopped, briskly moved itself its own

width sidewise, and rolled back. On the way it competently manicured the

lawn. It picked up leaves, retrieved a stray cigarette-butt, and snapped

up a scrap of paper blown from somewhere. Its tactile units touched a

new-planted shrub. It delicately circled the shrub and went on upon its

proper course.



* * * * *



Once, where the grass grew taller than elsewhere, it stopped and

whirred, trimming the growth back to regulation height. Then it went on

about its business as before.



Sergeant Bellews felt a warm sensation. That was a good machine that had

been in a bad way and he'd brought it back to normal, happy operation.

The sergeant was pleased.



The lieutenant turned into the Communications building. Sergeant Bellews

followed at leisure. A jeep went past him--one of the special jeeps

being developed at this particular installation--and its driver was

talking to someone in the back seat, but the jeep matter-of-factly

turned out to avoid Sergeant Bellews. He glowed. He'd activated it.

Another good machine, gathering sound experience day by day.



He went into the room where Betsy stood--the communicator which, alone

among receiving devices in the whole world, picked up the enigmatic

broadcasts consistently. Betsy was a standard Mark IV communicator, now

carefully isolated from any aerial. She was surrounded by recording

devices for vision and sound, and by the most sensitive and complicated

instruments yet devised for the detection of short-wave radiation.

Nothing had yet been detected reaching Betsy, but something must. No

machine could originate what Betsy had been exhibiting on her screen and

emitting from her speakers.



Sergeant Bellews tensed instantly. Betsy's standby light quivered

hysterically from bright to dim and back again. The rate of quivering

was fast. It was very nearly a sine-wave modulation of the light--and

when a Mahon-modified machine goes into sine-wave flicker, it is the

same as Cheyne-Stokes breathing in a human.



He plunged forward. He jerked open Betsy's adjustment-cover and fairly

yelped his dismay. He reached in and swiftly completed corrective

changes of amplification and scanning voltages. He balanced a capacity

bridge. He soothed a saw-tooth resonator. He seemed to know by sheer

intuition what was needed to be done.



After a moment or two the standby lamp wavered slowly from

near-extinction to half-brightness, and then to full brightness and

back again. It was completely unrhythmic and very close to normal.



"Who done this?" demanded the sergeant furiously. "He had Betsy close to

fatigue collapse! He'd ought to be court-martialed!"



He was too angry to notice the three civilians in the room with the

colonel and the lieutenant who'd summoned him. The young officer looked

uncomfortable, but the colonel said authoritatively:



"Never mind that, Sergeant. Your Betsy was receiving something. It

wasn't clear. You had not reported, as ordered, so an attempt was made

to clarify the signals."



"Okay, Colonel!" said Sergeant Bellews bitterly. "You got the right to

spoil machines! But if you want them to work right you got to treat 'em

right!"



"Just so," said the colonel. "Meanwhile--this is Doctor Howell, Doctor

Graves, and Doctor Lecky. Sergeant Bellews, gentlemen. Sergeant, these

are not MDs. They've been sent by the Pentagon to work on Betsy."



* * * * *



"Betsy don't need workin' on!" said Sergeant Bellews belligerently.

"She's a good, reliable, experienced machine! If she's handled right,

she'll do better work than any machine I know!"



"Granted," said the colonel. "She's doing work now that no other machine

seems able to do--drawing scrambled broadcasts from somewhere that can

only be guessed at. They've been unscrambled and these gentlemen have

come to get the data on Betsy. I'm sure you'll cooperate."



"What kinda data do they want?" demanded Bellews. "I can answer most

questions about Betsy!"



"Which," the colonel told him, "is why I sent for you. These gentlemen

have the top scientific brains in the country, Sergeant. Answer their

questions about Betsy and I think some very high brass will be grateful.



"By the way, it is ordered that from now on no one is to refer to Betsy

or any work on these broadcasts, over any type of electronic

communication. No telephone, no communicator, no teletype, no radio, no

form of communication except viva voce. And that means you talking to

somebody else, Sergeant, with no microphone around. Understand? And from

now on you will not talk about anything at all except to these gentlemen

and to me."



Sergeant Bellews said incredulously:



"Suppose I got to talk to somebody in the Rehab Shop. Do I signal with

my ears and fingers?"



"You don't talk," said the colonel flatly. "Not at all."



Sergeant Bellews shook his head sadly. He regarded the colonel with such

reproach that the colonel stiffened. But Sergeant Bellews had a gift for

machinery. He had what amounted to genius for handling Mahon-modified

devices. So long as no more competent men turned up, he was apt to get

away with more than average.



The colonel frowned and went out of the room. The tall young lieutenant

followed him faithfully. The sergeant regarded the three scientists with

the suspicious air he displayed to everyone not connected with Mahon

units in some fashion.



"Well?" he said with marked reserve. "What can I tell you first?"



Lecky was the smallest of the three scientists. He said ingratiatingly,

with the faintest possible accent in his speech:



"The nicest thing you could do for us, Sergeant, would be to show us

that this--Betsy, is it?--with other machines before her, has developed

a contagious machine insanity. It would frighten me to learn that

machines can go mad, but I would prefer it to other explanations for the

messages she gives."



"Betsy can't go crazy," said Bellews with finality. "She's

Mahon-controlled, but she hasn't got what it takes to go crazy. A Mahon

unit fixes a machine so it can loaf and be a permanent dynamic system

that can keep acquired habits of operatin'. It can take trainin'. It can

get to be experienced. It can learn the tricks of its trade, so to

speak. But it can't go crazy!"



"Too bad!" said Lecky. He added persuasively: "But a machine can lie,

Sergeant? Would that be possible?"



Sergeant Bellews snorted in denial.



* * * * *



"The broadcasts," said Lecky mildly, "claim a remarkable reason for

certainty about an extremely grave danger which is almost upon the

world. If it's the truth, Sergeant, it is appalling. If it is a lie, it

may be more appalling. The Joint Chiefs of Staff take it very seriously,

in any case. They--"



"I got cold shivers," said Sergeant Bellews with irony. "I'm all wrought

up. Huh! The big brass gets the yellin' yollups every so often anyhow.

Listen to them, and nothin' happens except it's top priority top secret

extra crash emergency! What do you want to know about Betsy?"



There was a sudden squealing sound from the communicator on which all

the extra recording devices were focussed. Betsy's screen lighted up.

Peculiarly curved patterns appeared on it. They shifted and changed.

Noises came from her speaker. They were completely unearthly. Now they

were shrill past belief, and then they were chopped into very small bits

of sound, and again they were deepest bass, when each separate note

seemed to last for seconds.



"You might," said Lecky calmly, "tell us from where your Betsy gets the

signal she reports in this fashion."



There were whirrings as recorders trained upon Betsy captured every

flickering of her screen and every peeping noise or deep-toned rumble.

The screen-pattern changed with the sound, but it was not linked to it.

It was a completely abnormal reception. It was uncanny. It was somehow

horrible because so completely remote from any sort of human

communication in the year 1972.



The three scientists watched with worried eyes. A communicator, even

with a Mahon unit in it, could not originate a pattern like this! And

this was not conceivably a distortion of anything transmitted in any

normal manner in the United States of America, or the Union of Compubs,

or any of the precariously surviving small nations not associated with

either colossus.



"This is a repeat broadcast!" said one of the three men suddenly. It was

Howell, the heavy-set man. "I remember it. I saw it projected--like

this, and then unscrambled. I think it's the one where the social

system's described--so we can have practice at trying to understand.

Remember?"



* * * * *



Lecky said, as if the matter had been thrashed out often before:



"I do not believe what it says, Howell! You know that I do not believe

it! I will not accept the theory that this broadcast comes from the

future!"



The broadcast stopped. It stopped dead. Betsy's screen went blank. Her

wildly fluctuating standby light slowed gradually to a nearly normal

rate of flicker.



"That's not a theory," said Howell dourly. "It's a statement in the

broadcast. We saw the first transmission of this from the tape at the

Pentagon. Then we saw it with the high-pitched parts slowed down and the

deep-bass stuff speeded up. Then it was a human voice giving data on the

scanning pattern and then rather drearily repeating that history said

that intertemporal communication began with broadcasts sent back from

2180 to 1972. It said the establishment of two-way communication was

very difficult and read from a script about social history, to give us

practice in unscrambling it. It's not a theory to say the stuff

originates in the future. It's a statement."



"Then it is a lie," said Lecky, very earnestly. "Truly, Howell, it is a

lie!"



"Then where does the broadcast come from?" demanded Howell. "Some say

it's a Compub trick. But if they were true they'd hide it for use to

produce chaos in a sneak attack. The only other theory--"



* * * * *



Graves, the man with the short moustache, said jerkily:



"No, Howell! It is not an extra-terrestrial creature pretending to be a

man of our own human future. One could not sleep well with such an idea

in his head. If some non-human monster could do this--"



"I do not sleep at all," said Lecky simply. "Because it says that

two-way communication is to come. I can listen to these broadcasts

tranquilly, but I cannot bear the thought of answering them. That seems

to me madness!"





Sergeant Bellews said approvingly:



"You got something there! Yes, sir! Did you notice how Betsy's standby

light was wabbling while she was bringin' in that broadcast? If she

could sweat, she'd've been sweating!"



Lecky turned his head to stare at the sergeant.



"Machines," said Bellews profoundly, "act according to the golden rule.

They do unto you as they would have you do unto them. You treat a

machine right and it treats you right. You treat it wrong and it busts

itself--still tryin' to treat you right. See?"



Lecky blinked.



"I do not quite see how it applies," he said mildly.



"Betsy's an old, experienced machine," said the sergeant. "A signal that

makes her sweat like that has got something wrong about it. Any ordinary

machine 'ud break down handlin' it."



Graves said jerkily:



"The other machines that received these broadcasts did break down,

Sergeant. All of them."



"Sure!" said the sergeant with dignity. "O' course, who's broadcastin'

may have been tinkerin' with their signal since they seen it wasn't

gettin' through. Betsy can take it now, when younger machines with less

experience can't. Maybe a micro-microwatt of signal. Then it makes her

sweat. If she was broadcastin', with a hell of a lot more'n a

micro-microwatt--it'd be bad! I bet you that every machine we make to

broadcast breaks down! I bet--"



Howell said curtly:



"Reasonable enough! A signal to pass through time as well as space would

be different from a standard wave-type! Of course that must be the

answer."



Sergeant Bellews said truculently:



"I got a hunch that whoever's broadcastin' is busting transmitters right

an' left. I never knew anything about this before, except that Betsy was

pickin' up stuff that came from nowhere. But I bet if you look over the

record-tapes you will find they got breaks where one transmitter

switched off or broke down and another took over!"



Lecky's eyes were shining. He regarded Sergeant Bellews with a sort of

tender respect.



"Sergeant Bellews," he said softly, "I like you very much. You have told

us undoubtedly true things."



"Think nothin' of it," said the sergeant, gratified. "I run the Rehab

Shop here, and I could show you things--"



"We wish you to," said Lecky. "The reaction of machines to these

broadcasts is the one viewpoint we would never have imagined. But it is

plainly important. Will you help us, Sergeant? I do not like to be

frightened--and I am!"



"Sure, I'll help," said Sergeant Bellews largely. "First thing is to

whip some stuff together so we can find out what's what. You take a few

Mahon units, and install 'em and train 'em right, and they will do

almost anything you've a mind for. But you got to treat 'em right.

Machines work by the golden rule. Always! Come along!"



* * * * *



Sergeant Bellews went to the Rehab Shop, followed only by Lecky. All

about, the sun shone down upon buildings with a remarkably temporary

look about them, and on lawns with a remarkably lush look about them,

and signboards with very black lettering on gray paint backgrounds.

There was a very small airfield inside the barbed-wire fence about the

post, and elaborate machine-shops, and rows and rows of barracks and a

canteen and a USO theatre, and a post post-office. Everything seemed

quite matter-of-fact.



Except for the machines.



They were the real reason for the existence of the post. The barracks

and married-row dwellings had washing-machines which looked very much

like other washing-machines, except that they had standby lights which

flickered meditatively when they weren't being used.



* * * * *



The television receivers looked like other TV sets, except for minute

and wavering standby lights which were never quite as bright or dim one

moment as the next. The jeeps--used strictly within the barbed-wire

fence around the post--had similar yellow glowings on their

instrument-boards, and they were very remarkable jeeps. They never ran

off the graveled roads onto the grass, and they never collided with each

other, and it was said that the nine-year-old son of a lieutenant-colonel

had tried to drive one and it would not stir. Its motor cut off when he

forced it into gear. When he tried to re-start it, the starter did not

turn. But when an adult stepped into it, it operated perfectly--only it

braked and stopped itself when a small child toddled into its path.



There were some people who said that this story was not true, but other

people insisted that it was. Anyhow the washing-machines were perfect.

They never tangled clothes put into them. It was reported that Mrs.

So-and-so's washing-machine had found a load of clothes tangled, and

reversed itself and worked backward until they were straightened out.



Television sets turned to the proper channels--different ones at

different times of day--with incredible facility. The smallest child

could wrench at a tuning-knob and the desired station came on. All the

operating devices of Research Installation 83 worked as if they liked

to--which might have been alarming except that they never did anything

of themselves. They initiated nothing. But each one acted like an old,

favorite possession. They fitted their masters. They seemed to tune

themselves to the habits of their owners. They were infinitely easy to

work right, and practically impossible to work wrong.



Such machines, of course, had not been designed to cope with enigmatic

broadcasts or for military purposes. But the jet-planes on the small

airfield were very remarkable indeed, and the other and lesser devices

had been made for better understanding of the Mahon units which made

machines into practically a new order of creation.



* * * * *



Sergeant Bellews ushered Lecky into the Rehab Shop. There was the

pleasant, disorderly array of devices with their wavering standby

lights. They gave an effect of being alive, but somehow it was not

disturbing. They seemed not so much intent as meditative, and not so

much watchful as interested. When the sergeant and his guest moved past

them, the unrhythmic waverings of the small yellow lights seemed to

change hopefully, as if the machines anticipated being put to use.

Which, of course, was absurd. Mahon machines do not anticipate anything.

They probably do not remember anything, though patterns of operation are

certainly retained in very great variety. The fact is that a Mahon unit

is simply a device to let a machine stand idle without losing the nature

of an operating machine.



The basic principle goes back to antiquity. Ships, in ancient days, had

manners and customs individual to each vessel. Some were sweet craft,

easily handled and staunch and responsive. Others were stubborn and

begrudging of all helpfulness. Sometimes they were even man-killers.

These facts had no rational explanation, but they were facts. In

similarly olden times, particular weapons acquired personalities to the

point of having personal names--Excalibur, for example.



Every fighting man knew of weapons which seemed to possess personal

skill and ferocity. Later, workmen found that certain tools had a knack

of fitting smoothly in the hand--seeming even to divine the grain of the

wood they worked on. The individual characteristics of violins were

notorious, so that a violin which sang joyously under the bow was

literally priceless.



And all these things, as a matter of observation and not of

superstition, kept their qualities only when in constant use. Let a ship

be hauled out of water and remain there for a time, and she would be

clumsy on return to her native element. Let a sword or tool stay unused,

and it seemed to dull. In particular, the finest of violins lost its

splendor of tone if left unplayed, and any violin left in a repair-shop

for a month had to be played upon constantly for many days before its

living tone came back.



* * * * *



The sword and the tool perhaps, but the ship and the violin certainly,

acted as if they acquired habits of operation by being used, and lost

them by disuse. When more complex machines were invented, such facts

were less noticeable. True, no two automobiles ever handled exactly the

same, and that was recognized. But the fact that no complex machine

worked well until it had run for a time was never commented on, except

in the observation that it needed to be warmed up. Anybody would have

admitted that a machine in the act of operating was a dynamic system in

a solid group of objects, but nobody reflected that a stopped machine

was a dead thing. Nobody thought to liken the warming-up period for an

aeroplane engine to the days of playing before a disuse-dulled violin

regained its tone.



Yet it was obvious enough. A ship and a sword and a tool and a violin

were objects in which dynamic systems existed when they were used, and

in which they ceased to exist when use stopped. And nobody noticed that

a living creature is an object which contains a dynamic system when it

is living, and loses it by death.



For nearly two centuries quite complex machines were started, and warmed

up, and used, and then allowed to grow cold again. In time the more

complex machines were stopped only reluctantly. Computers, for example,

came to be merely turned down below operating voltage when not in use,

because warming them up was so difficult and exacting a task. Which was

an unrecognized use of the Mahon principle. It was a way to keep a

machine activated while not actually operating. It was a state of rest,

of loafing, of idleness, which was not the death of a running mechanism.



The Mahon unit was a logical development. It was an absurdly simple

device, and not in the least like a brain. But to the surprise of

everybody, including its inventor, a Mahon-modified machine did more

than stay warmed up. It retained operative habits as no complex device

had ever done before. In time it was recognized that Mahon-modified

machines acquired experience and kept it so long as the standby light

glowed and flickered in its socket. If the lamp went out the machine

died, and when reenergized was a different individual entirely, without

experience.



Sergeant Bellews made such large-minded statements as were needed to

brief Lecky on the work done in this installation with Mahon-controlled

machines.



"They don't think," he explained negligently, "any more than dogs think.

They just react--like dogs do. They get patterns of reaction. They get

trained. Experienced. They get good! Over at the airfield they're

walking around beaming happy over the way the jets are flyin'

themselves."



Lecky gazed around the Rehab Shop. There were shelves of machines, duly

boxed and equipped with Mahon units, but not yet activated. Activation

meant turning them on and giving them a sort of basic training in the

tasks they were designed to do. But also there were machines which had

broken down--invariably through misuse, said Sergeant Bellews

acidly--and had been sent to the Rehab Shop to be re-trained in their

proper duties.



"Guys see 'em acting sensible and obediently," said Bellews with

bitterness, "and expect 'em to think. Over at the jet-field they finally

come to understand." His tone moderated. "Now they got jets that put

down their own landing-gear, and holler when fuel's running low, and do

acrobatics happy if you only jiggle the stick. They mighty near fly

themselves! I tell you, if well-trained Mahon jets ever do tangle with

old-style machines, it's goin' to be a caution to cats! It'll be like a

pack of happy terriers pilin' into hamsters. It'll be murder!"



* * * * *



He surveyed his stock. From a back corner he brought out a small machine

with an especially meditative tempo in its standby-lamp flicker. The

tempo accelerated a little when he put it on a work-bench.



"They got batteries to stay activated with," he observed, "and only need

real juice when they're workin'. This here's a play-back recorder they had

over in Recreation. Some guys trained it to switch frequencies--speed-up

and slow-down stuff. They laughed themselves sick! There used to be a

tough guy over there,--a staff sergeant, he was--that gave lectures on

military morals in a deep bass voice. He was proud of that bull voice

of his. He used it frequently. So they taped him, and Al here--" the

name plainly referred to the machine--"used to play it back switched

up so he sounded like a squeaky girl. That poor guy, he liked to busted

a blood-vessel when he heard himself speakin' soprano. He raised hell

and they sent Al here to be rehabilitated. But I switched another machine

for him and sent it back, instead. Of course, Al don't know what he's

doing, but--"



* * * * *



He brought over another device, slightly larger and with a screen.



"Somebody had a bright notion with this one, too," he said. "They

figured they'd scramble pictures for secret transmission, like they

scramble voice. But they found they hadda have team-trained sets to

work, an' they weren't interchangeable. They sent Gus here to be

deactivated an' trained again. I kinda hate to do that. Sometimes you

got to deactivate a machine, but it's like shooting a dog somebody's

taught to steal eggs, who don't know it's wrong."



He bolted the two instruments together. He made connections with

flexible cables and tucked the cable out of sight. He plugged in for

power and began to make adjustments.



The small scientist asked curiously:



"What are you preparing, Sergeant?"



"These two'll unscramble that broadcast," said Sergeant Bellews, with

tranquil confidence. "Al's learned how to make a tape and switch

frequencies expert. Gus, here, he's a unscrambler that can make any

kinda scanning pattern. Together they'll have a party doing what they're

special trained for. We'll hook 'em to Betsy's training-terminals."



He regarded the two machines warmly. Connected, now, their standby

lights flickered at a new tempo. They synchronized, and broke synchrony,

and went back into elaborate, not-quite-resolvable patterns which were

somehow increasingly integrated as seconds went by.



"Those lights look kinda nice, don't they?" asked the sergeant

admiringly. "Makes you think of a coupla dogs gettin' acquainted when

they're goin' out on a job of hunting or something."



But Lecky said abruptly, in amazement:



"But, Sergeant! In the Pentagon it takes days to unscramble a received

broadcast such as Betsy receives! It requires experts--"



"Huh!" said Sergeant Bellews. He picked up the two machines. "Don't get

me started about the kinda guys that wangle headquarters-company jobs!

They got a special talent for fallin' soft. But they haven't necessarily

got anything else!"



* * * * *



Lecky followed Sergeant Bellews as the sergeant picked up his new

combination of devices and headed out of the Rehab Shop. Outside, in the

sunshine, there were roarings to be heard. Lecky looked up. A formation

of jets swam into view against the sky. A tiny speck, trailing a

monstrous plume of smoke, shot upward from the jet-field. The formation

tightened.



The ascending jet jiggled as if in pure exuberance as it swooped

upward--but the jiggle was beautifully designed to throw standard

automatic gunsights off.



A plane peeled off from the formation and dived at the ascending ship.

There was a curious alteration in the thunder of motors. The

rate-of-rise of the climbing jet dwindled almost to zero. Sparks shot

out before it. They made a cone the diving ship could not avoid. It sped

through them and then went as if disappointedly to a lower level. It

stood by to watch the rest of the dog-fight.



"Nice!" said Sergeant Bellews appreciatively. "That's a Mahon jet all by

itself, training against regular ships. They have to let it shoot

star-bullets in training, or it'd get hot and bothered in a real fight

when its guns went off."



The lower jet streaked skyward once more. Sparks sped from the

formation. They flared through emptiness where the Mahon jet had been

but now was not. It scuttled abruptly to one side as concerted streams

of sparks converged. They missed. It darted into zestful, exuberant

maneuverings, remarkably like a dog dashing madly here and there in pure

high spirits. The formation of planes attacked it resolutely.



Suddenly the lone jet plunged into the midst of the formation, there

were coruscations of little shooting stars, and one-two-three planes

disgustedly descended to lower levels as out of action. Then the single

ship shot upward, seemed eagerly to shake itself, plunged back--and the

last ships tried wildly to escape, but each in turn was technically shot

down.



The Mahon jet headed back for its own tiny airfield. Somehow, it looked

as if, had it been a dog, it would be wagging its tail and panting

happily.



"That one ship," said Lecky blankly, "it defeated the rest?"



"It's got a lot of experience," said the sergeant. "You can't beat

experience."



He led the way into Communications Center. In the room where Betsy

stood, Howell and Graves had been drawing diagrams at each other to the

point of obstinacy.



"But don't you see?" insisted Howell angrily. "There can be no source

other than a future time! You can't send short waves through

three-dimensional space to a given spot and not have them interceptible

between. Anyhow, the Compubs wouldn't work it this way! They wouldn't

put us on guard! And an extra-terrestrial wouldn't pretend to be a human

if he honestly wanted to warn us of danger! He'd tell us the truth!

Physically and logically it's impossible for it to be anything but what

it claims to be!"



Graves said doggedly:



"But a broadcast originating in the future is impossible!"



"Nothing," snapped Howell, "that a man can imagine is impossible!"



"Then imagine for me," said Graves, "that in 2180 they read in the

history books about a terrible danger to the human race back in 1972,

which was averted by a warning they sent us. Then, from their

history-books, which we wrote for them, they learn how to make a

transmitter to broadcast back to us. Then they tell us how to make a

transmitter to broadcast ahead to them. They don't invent the

transmitter. We tell them how to make it--via a history book. We don't

invent it. They tell us--from the history book. Now imagine for me how

that transmitter got invented!"



"You're quibbling," snapped Howell. "You're refusing to face a fact

because you can't explain it. I say face the fact and then ask for an

explanation!"



"Why not ask them," said Graves, "how to make a round square or a

five-sided triangle?"



* * * * *



Sergeant Bellews pushed to a spot near Betsy. He put down his now-linked

Mahon machines and began to move away some of the recording apparatus

focused on Betsy.



"Hold on there!" said Howell in alarm. "Those are recorders!"



"We'll let 'em record direct," said the sergeant.



* * * * *



Lecky spoke feverishly in support of Bellews. But what he said was, in

effect, a still-marveling description of the possibilities of

Mahon-modified machines. They were, he said with ardent enthusiasm, the

next step in the historic process by which successively greater portions

of the cosmos enter into a symbiotic relationship with man. Domestic

animals entered into such a partnership aeons ago. Certain plants--wheat

and the like--even became unable to exist without human attention. And

machines were wrought by man and for a long time served him reluctantly.

Pre-Mahon machines were tamed, not domestic. They wore themselves out

and destroyed themselves by accidents. But now there were machines which

could enter into a truly symbiotic relationship with humanity.



"What," demanded Howell, "what in hell are you talking about?"



Lecky checked himself. He smiled abashedly:



"I think," he said humbly, "that I speak of the high destiny of mankind.

But the part that applies at the moment is that Sergeant Bellews must

not be interfered with."



He turned and ardently assisted Sergeant Bellews in making room for the

just-brought devices. Sergeant Bellews led flexible cables from them to

Betsy. He inserted their leads in her training-terminals. He made

adjustments within.



It became notable that Betsy's standby light took up new tempos in its

wavering. There were elaborate interweavings of rate and degree of

brightening among the lights of all three instruments. There was no

possible way to explain the fact, but a feeling of pleasure, of zestful

stirring, was somehow expressed by the three machines which had been

linked together into a cooperating group.



Sergeant Bellews eased himself into a chair.



"Now everything's set," he observed contentedly. "Remember, I ain't seen

any of these broadcasts unscrambled. I don't know what it's all about.

But we got three Mahon machines set up now to work on the next crazy

broadcast that comes in. There's Betsy and these two others. And all

machines work accordin' to the Golden Rule, but Mahon machines--they are

honey-babes! They'll bust themselves tryin' to do what you ask 'em. And

I asked these babies for plenty--only not enough to hurt 'em. Let's see

what they turn out."



He pulled a pipe and tobacco from his pocket. He filled the pipe. He

squeezed the side of the bowl and puffed as the tobacco glowed. He

relaxed, underneath the wall-sign which sternly forbade smoking by all

military personnel within these premises.



It was nearly three hours--but it could have been hundreds--before

Betsy's screen lighted abruptly.



* * * * *



The broadcast came in; a new transmission. The picture-pattern on

Betsy's screen was obviously not the same as other broadcasts from

nowhere. The chirps and peepings and the rumbling deep sounds were not

repetitions of earlier noise-sequences. It should have taken many days

of finicky work by technicians at the Pentagon before the originally

broadcast picture could be seen and the sound interpreted. But a

play-back recorder named Al, and a picture-unscrambler named Gus were in

closed-circuit relationship with Betsy. She received the broadcast and

they unscrambled the sound and vision parts of it immediately.



The translated broadcast, as Gus and Al presented it, was calculated to

put the high brass of the defense forces into a frenzied tizzy. The

anguished consternation of previous occasions would seem like very calm

contemplation by comparison. The high brass of the armed forces should

grow dizzy. Top-echelon civilian officials should tend to talk

incoherently to themselves, and scientific consultants--biologists in

particular--ought to feel their heads spinning like tops.



The point was that the broadcast had to be taken seriously because it

came from nowhere. There was no faintest indication of any signal

outside of Betsy's sedately gray-painted case. But Betsy was not making

it up. She couldn't. There was a technology involved which required the

most earnest consideration of the message carried by it.



And this broadcast explained the danger from which the alleged future

wished to rescue its alleged past. A brisk, completely deracialized

broadcaster appeared on Gus's screen.



In clipped, oddly stressed, but completely intelligible phrases, he

explained that he recognized the paradox his communication represented.

Even before 1972, he observed, there had been argument about what would

happen if a man could travel in time and happened to go back to an

earlier age and kill his grandfather. This communication was an

inversion of that paradox. The world of 2180 wished to communicate back

in time and save the lives of its great-great-great-grandparents so that

it--the world of 2180--would be born.



Without this warning and the information to be given, at least half the

human race of 1972 was doomed.



In late 1971 there had been a mutation of a minor strain of

staphylococcus somewhere in the Andes. The new mutation thrived and

flourished. With the swift transportation of the period, it had spread

practically all over the world unnoticed, because it produced no

symptoms of disease.



Half the members of the human race were carriers of the harmless mutated

staphylococcus now, but it was about to mutate again in accordance

with Gordon's Law (the reference had no meaning in 1972) and the new

mutation would be lethal. In effect, one human being in two carried in

his body a semi-virus organization which he continually spread, and

which very shortly would become deadly. Half the human race was bound to

die unless it was instructed as to how to cope with it. Unless--



* * * * *



Unless the world of 2180 told its ancestors what to do about it. That

was the proposal. Two-way communication was necessary for the purpose,

because there would be questions to be answered, obscure points to be

clarified, numerical values to be checked to the highest possible degree

of accuracy.



Therefore, here were diagrams of the transmitter needed to communicate

with future time. Here were enlarged diagrams of individual parts. The

enigmatic parts of the drawing produced a wave-type unknown in 1972. But

a special type of wave was needed to travel beyond the three dimensions

of ordinary space, into the fourth dimension which was time. This

wave-type produced unpredictable surges of power in the transmitter,

wherefore at least six transmitters should be built and linked together

so that if one ceased operation another would instantly take up the

task.



* * * * *



The broadcast ended abruptly. Betsy's screen went blank. The colonel was

notified. A courier took tapes to Washington by high-speed jet. Life in

Research Establishment 83 went on sedately. The barracks and the married

quarters and the residences of the officers were equipped with

Mahon-modified machines which laundered diapers perfectly, and with dial

telephones which always rang right numbers, and there were police-up

machines which took perfect care of lawns, and television receivers

tuned themselves to the customary channels for different hours with

astonishing ease. Even jet-planes equipped with Mahon units almost

landed themselves, and almost flew themselves about the sky in simulated

combat with something very close to zest.



But the atmosphere in the room in Communications was tense.



"I think," said Howell, with his lips compressed, "that this answers all

your objections, Graves. Motive--"



"No," said Lecky painfully. "It does not answer mine. My objection is

that I do not believe it."



"Huh!" said Sergeant Bellews scornfully. "O' course, you don't believe

it! It's phoney clear through!"



Lecky looked at him hopefully.



"You noticed something that we missed, Sergeant?"



"Hell, yes!" said Sergeant Bellews. "That transmitter diagram don't have

a Mahon unit in it!"



"Is that remarkable?" demanded Howell.



"Remarkable dumb," said the sergeant. "They'd ought to know--"



The tall young lieutenant who earlier had fetched Sergeant Bellews to

Communications now appeared again. He gracefully entered the room where

Betsy waited for more broadcast matter. Her standby light flickered with

something close to animation, and the similar yellow bulbs on Al and Gus

responded in kind. The tall young lieutenant said politely:



"I am sorry, but pending orders from the Pentagon the colonel has

ordered this room vacated. Only automatic recorders will be allowed

here, and all records they produce will be sent to Washington without

examination. It seems that no one on this post has the necessary

clearance for this type of material."



Lecky blinked. Graves sputtered:



"But--dammit, do you mean we can work out a way to receive a broadcast

and not be qualified to see it?"



"There's a common-sense view," said Sergeant Bellews oracularly, "and a

crazy view, and there's what the Pentagon says, which ain't either." He

stood up. "I see where I go back to my shop and finish rehabilitatin'

the colonel's vacuum cleaner. You gentlemen care to join me?"



Howell said indignantly:



"This is ridiculous! This is absurd!"



"Uh-uh," said Sergeant Bellews benignly. "This is the armed forces.

There'll be an order makin' some sort of sense come along later.

Meanwhile, I can brief you guys on Mahon machines so you'll be ready to

start up again with better information when a clearance order does come

through. And I got some beer in my quarters behind the Rehab Shop. Come

along with me!"



He led the way out of the room. The young lieutenant paused to close the

door firmly behind him and to lock it. A bored private, with side-arms,

took post before it. The lieutenant was a very conscientious young man.



But he did not interfere with the parade to Sergeant Bellews' quarters.

The young lieutenant was very military, and the ways of civilians were

not his concern. If eminent scientists chose to go to Sergeant Bellews'

quarters instead of the Officers Club, to which their assimilated rank

entitled them, it was strictly their affair.



* * * * *



They reached the Rehab Shop, and Sergeant Bellews went firmly to a

standby-light-equipped refrigerator in his quarters. He brought out beer

and deftly popped off the tops. The icebox door closed quietly.



"Here's to crime," said Sergeant Bellews amiably.



He drank. Howell sipped gloomily. Graves drank thoughtfully. Lecky

looked anticipative.



"Sergeant," he said, "did I see a gleam in your eye just now?"



Sergeant Bellews reflected, gently shaking his opened beer-can with a

rotary motion, for no reason whatever.



"Uh-uh," he rumbled. "I wouldn't say a gleam. But you mighta seen a

glint. I got some ideas from what I seen during that broadcast. I wanna

get to work on 'em. Here's the place to do the work. We got facilities

here."



Howell said with precise hot anger:



"This is the most idiotic situation I have ever seen even in government

service!"



"You ain't been around much," the sergeant told him kindly. "It happens

everywhere. All the time. It ain't even a exclusive feature of the armed

forces." He put down his beer-can and patted his stomach. "There's guys

who sit up nights workin' out standard operational procedures just to

make things like this happen, everywhere. The colonel hadda do what he

did. He's got orders, too. But he felt bad. So he sent the lieutenant to

tell us. He does the colonel's dirty jobs--and he loves his work."



* * * * *



He moved grandly toward the Rehab Shop proper, which opened off the

quarters he lived in--very much as a doctor's office is apt to open off

his living quarters.



"We follow?" asked Lecky zestfully. "You plan something?"



"Natural!" said Sergeant Bellews largely.



He led the way into the Rehab Shop, which was dark and shadowy, and only

very dimly lighted by flickering, wavering lights of many machines

waiting as if hopefully to be called on for action. There were the

shelves of machines not yet activated. Sergeant Bellews led the way

toward his desk. There was a vacuum cleaner on it, on standby. He put it

down on the floor.



Lecky watched him with some eagerness. The others came in, Howell dourly

and Graves wiping his moustache.



The sergeant considered his domain.



"We'll be happy to help you," said Lecky.



"Thanks," said the sergeant. "I'm under orders to help you, too, y'know.

Just supposing you asked me to whip up something to analyze what Betsy

receives, so it can be checked on that it is a new wave-type."



"Can you do that?" demanded Graves. "We were supposed to work on

that--but so far we've absolutely nothing to go on!"



The sergeant waved his hand negligently.



"You got something now. Betsy's a Mahon-modified device. Every receiver

that picked up one of those crazy broadcasts broke down before it was

through. She takes 'em in her stride--especial with Al and Gus to help

her. Wouldn't it be reasonable to guess that Mahon machines

are--uh--especial adapted to handle intertemporal communication?"



"Very reasonable!" said Howell dourly. "Very! The broadcast said that

the wave-type produced unpredictable surges of current. Ordinary

machines do find it difficult to work with whatever type of radiation

that can be."



"Betsy chokes off those surges," observed the sergeant. "With Gus and Al

to help, she don't have no trouble. We hadn't ought to need to make any

six transmitters if we put Mahon-unit machines together for the job!"



"Quite right," agreed Lecky, mildly. "And it is odd--"



"Yeah," said the sergeant. "It's plenty odd my

great-great-great-grandkids haven't got sense enough to do it

themselves!"



* * * * *



He went to a shelf and brought down a boxed machine,--straight from the

top-secret manufactory of Mahon units. It had never been activated. Its

standby light did not glow. Sergeant Bellews ripped off the carton and

said reflectively:



"You hate to turn off a machine that's got its own ways of working. But

a machine that ain't been activated has not got any personality. So you

don't mind starting it up to turn it off later."



He opened the adjustment-cover and turned something on. The standby

light glowed. Closely observed, it was not a completely steady glow.

There were the faintest possible variations of brightness. But there was

no impression of life.



Graves said:



"Why doesn't it flicker like the others?"



"No habits," said the sergeant. "No experience. It's like a newborn

baby. It'll get to have personality after it's worked a while. But not

now."



He went across the shop again. He moved out a heavy case, and twisted

the release, and eased out a communicator of the same type--Mark IV--as

Betsy back in the Communications room. Howell went to help him. Graves

tried to assist. Lecky moved other things out of the way. They were

highly eminent scientists, and Metech Sergeant Bellews was merely a

non-commissioned officer in the armed forces. But he happened to have

specialized information they had not. Quite without condescension they

accepted his authority in his own field, and therefore his equality. As

civilians they had no rank to maintain, and they disagreed with each

other--and would disagree with the sergeant--only when they knew why.

Which was one of the reasons why they were eminent scientists.



Sergeant Bellews brought out yet another box. He unrolled cables. He

selected machines whose flickering lights seemed to bespeak eagerness to

be of use. He coupled them to the newly unboxed machines, whose lights

were vaguely steady.



"Training cables," he said over his shoulder. "You get one machine

working right, and you hook it with another, and the new machine kinda

learns from the old one. Kinda! But it ain't as good as real experience.

Not at first."



* * * * *



Presently the lights of the newly energized machines began to waver in

somewhat the manner of the ready-for-operation ones. But they did not

give so clear an impression of personality.



"Look!" said Sergeant Bellews abruptly. "I got to check with you. The

more I think, the more worried I get."



"You begin to believe the broadcasts come from the future?" demanded

Graves. "And it worries you? But they do not speak of Mahon units--"



"I don't care where they come from," said the sergeant. "I'm worryin'

about what they are! The guy in the broadcast--not knowing Mahon

units--said we'd have to make half a dozen transmitters so they'd take

over one after another as they blew out. You see what that means?"



Lecky said crisply:



"You pointed it out before. There is something in the wave-type

which--you would say this, Sergeant!--which machines do not like. Is

that the reasoning?"



"Uh-uh!" The sergeant scowled. "Machines work by the golden rule. They

try to do unto you what they want you to do unto them. Likes an'

dislikes don't matter. I mean that there's something about that

wave-type that machines can't take! It busts them. If it sort of

explodes surges of current in 'em--Look! Any running machine is a

dynamic system in a object. A jet-plane operating is that. So's a

water-spout. So's a communicator. But if you explode surges of heavy

current in a dynamic system in a operating machine--things get messed

up. The operating habit is busted to hell. I'm saying that if this

wave-type makes crazy surges of current start up--why--if the surges

are strong enough they'll bust not only a communicator but a jet-plane.

Or a water-spout. Anything! See?"



* * * * *



Lecky blinked and suddenly went pale.



"But," said Howell reasonably, "you said that Betsy handled it.

Especially well when linked with other Mahon machines."



"Yeah," said the sergeant.



"I think," observed Graves jerkily, "that you are preparing new

machines, without developed--personalities, because you think that if

they make this special-type wave they'll be broken."



"Yeah," said the sergeant, again. "The signal Betsy was amplifyin'

coulda been as little as a micro-micro-watt. At its frequency an' type,

she'd choke it down if it was more. But even a micro-micro-watt bothered

Betsy until she got Al and Gus to help. She was fair screamin' for

somebody to come help her hold it. But the three of them done all

right."



Howell conceded the point.



"That seems sound reasoning."



"But you don't broadcast with a micro-micro-watt. You use a hell of a

lot more power than that! The transmitter the guy in the screen said to

make was a twenty-kilowatt job. Not too much for a broadcast of sine

waves, but a hell of a lot to be turned loose, in waves that have Betsy

hollerin' at the power she was handlin'!"



"It might break even the Mahon machines in this installation?" demanded

Howell.



"You're gettin' warm," said the sergeant.



Graves said:



"You mean it might break all operating communicators in a very large

area?"



"You're gettin' hot," said the sergeant grimly.



Lecky wetted his lips.



"I think," he said very carefully, "that you suspect it is a wave-type

which will break any dynamic system, in any sort of object a dynamic

system can exist in."



"Yeah," said the sergeant. He waited, looking at Lecky.



"And," said Lecky, "not only operating machines are dynamic systems.

Living plants and animals are, too. So are men."



"That's what I'm drivin' at," said Sergeant Bellews.



"So you believe," said Lecky, very pale indeed, "that we have been given

the circuit-diagram of a transmitter which will broadcast a wave-type

which destroys dynamic systems--life as well as the operation of

machines. Persons--in the future or an alien creature in a space-ship,

or perhaps even the Compubs--are furnishing us with designs for

transmitters of death, to be linked together so that if one fails the

others will carry on. And they lure us to destroy ourselves by lying

about who they are and what they propose."



"They're lyin'," said the sergeant. "They say they're in the future and

they don't know a thing about Mahon units. Else they'd use 'em."



Lecky wetted his lips again.



"And--if they are not in the future, they are trying to get us to

destroy ourselves because that would be safer and surer than trying to

destroy us by--say--transmitters of death dropped upon us by parachute.

Yet if we do not destroy ourselves, they will surely do that."



"If we don't bump ourselves off, it'll be because we got wise,"

acknowledged the sergeant. "If we get wise, we could bump them off by

parachute-transmitter. So they'll beat us to it. They'll have to!"



"Yes," said Lecky. "They'll have to. It has always been said that a

death-ray was impossible. This would be a death-broadcast. If we do not

broadcast, they will--whoever they are. It is--" He smiled mirthlessly

at the magnitude of his understatement. "It is urgent that we do

something. What shall we do, Sergeant?"



* * * * *



A squadron of light tanks arrived at Research Installation 83 that

afternoon, with a shipment of courier motorcycles. They had been

equipped with Mahon units and went to the post to be trained.



The Pentagon was debating the development of a Mahon-modified guided

missile, and a drone plane was under construction. But non-military

items also arrived for activation and test. Automatic telephone

switching systems, it appeared, could be made much simpler if they could

be trained to do their work instead of built so they couldn't help it.



Passenger-cars other than jeeps showed promise. It had long been known

that most accidents occurred with new cars, and that ancient jalopies

were relatively safe even in the hands of juvenile delinquents. It was

credible that part of the difference was in the operating habits of the

cars.



It appeared that humanity was upon the threshold of a new era, in which

the value of personality would reappear among the things taken for

granted. Strictly speaking, of course, Mahon machines were not persons.

But they reflected the personalities of their owners. It might again

seem desirable to be a decent human being if only because machines

worked better for them.



But it would be tragic if Mahon machines were used to destroy humankind

with themselves! Sergeant Bellews would have raged at the thought of

training a Mahon unit to guide an atom bomb. It would have to be--in a

fashion--deceived. He even disliked the necessity he faced that

afternoon while a courier winged his way to the Pentagon with the

top-secret tapes Betsy and Al and Gus had made.



The Rehab Shop was equipped not only to recondition machines but to test

them. One item of equipment was a generator of substitute broadcast

waves. It could deliver a carrier-wave down to half a micro-micro-watt

of any form desired, and up to the power of a nearby transmitter. It was

very useful for calibrating communicators. But Sergeant Bellews modified

it to allow of variations in type as well as frequency and amplitude.



"I'm betting," he grunted, "that there's different sorts of the

wave-type those guys want us to broadcast. Like there's a spectrum of

visible light. If we were color-blind and yellow'd bust things, they'd

transmit in red that we could see, and they'd tell us to broadcast

something in yellow that'd wipe us out. And we wouldn't have sense

enough not to broadcast the yellow, because we wouldn't know the

difference between it and red until we did broadcast. Then it'd be too

late."



Howell watched with tight-clamped jaws. He had committed himself to the

authenticity of the broadcasts claiming to be from a future time. Now he

was shaken, but only enough to admit the need for tests. Graves sat

unnaturally still. Lecky looked at Sergeant Bellews with a peculiarly

tranquil expression on his face.



"Only," grunted the sergeant, "it ain't frequency we got to figure, but

type. Nobody hardly uses anything but sine waves for communication, but

I got to make this gadget turn out a freak wave-type by guess and golly.

I got a sort of test for it, though."



* * * * *



He straightened up and connected a cable from the generator to the Mark

IV communicator which was a factory twin of Betsy.



"I'm gonna feed this communicator half a micro-micro-watt of stuff like

the broadcast--I think," he announced grimly. "I saw the diagrams of the

transmitters they want us to make. I'm guessing the broadcast-wave they

use is close to it but not exact. Close, because it's bad for machines.

Not exact, because they're alive while they use it. I hope I don't hit

anything on the nose. Okay?"



Lecky said gently:



"I have never been more frightened. Go ahead!"



Sergeant Bellews depressed a stud. The communicator's screen lighted up

instantly. It was receiving the generator's minute output and accepted

it as a broadcast. But the signal was unmodulated, so there was no image

nor any sound.



* * * * *



The communicator's standby light flickered steadily.



Sergeant Bellews adjusted a knob on the generator. The communicator's

standby flicker changed in amplitude. Bellews turned the knob back. He

adjusted another control. The standby light wavered crazily.



Graves said nervously:



"I think I see. You are trying to make this communicator react as Betsy

did. When it does, you will consider that your generator is creating a

wave like the broadcasts from nowhere."



"Yeah," said Bellews. "It ain't scien



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