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