The public abruptly ceased to be interested in news of the signals. Rather, it suddenly wanted to stop thinking about them. The public was scared. Throughout all human history, the most horrifying of all ideas has been the idea of something which was as intelligent as a man, but wasn't human. Evil spirits, ghosts, devils, werewolves, ghouls—all have roused maddened terror wherever they were believed in. Because they were intelligent but not men.

Now, suddenly, the world seemed to realize that there was a Something out on a tiny frozen rock in space. It signaled plaintively to Earth. It had to be intelligent to be able to send a signal for two hundred seventy million miles. But it was not a man. Therefore it was a monster. Therefore it was horrible. Therefore it was deadly and intolerable and scarey, and humans abruptly demanded not to hear any more about it. Perhaps they thought that if they didn't think about it, it would go away.

Newspaper circulations dropped. News-magazine sales practically vanished. A flood of hysterical letters demanded that the broadcasting networks leave such revolting things off the air. And this reaction was not only in America. Violent anti-American feeling arose in Europe, which psychologists analyzed as resentment caused by the fact that the Americans had answered the first broadcast. If they hadn't answered the first, there wouldn't have been a second. But also, even more violent anti-Russian feeling rose up, because the Russians had started a man off to meddle with the monster who piped so pleadingly. This antipathy to space caused a minor political upset in the Kremlin itself, where a man with a name ending in ov was degraded to much lower official rank and somebody with a name ending in sky took his place. This partly calmed the Russian public but had little effect anywhere else. The world was frightened. It looked for a victim, or victims, for its fear. Once upon a time, witches were burned to ease the terrors of ignorance, and plague-spreaders were executed in times of pestilence to assure everybody that now the plague would cease since somebody had been killed for spreading it.

Organizations came into being with the official and impassioned purpose of seeing that space research ceased immediately. Even more violent organizations demanded the punishment of everybody who had ever considered space travel a desirable thing. Congress cut some hundreds of millions from a guided-missile-space-exploration appropriation as a starter. A poor devil of a crackpot in Santa Monica, California, revealed what he said was a spaceship he'd built in his back yard to answer the signals from M-387. He intended to charge a quarter admission to inspect it, using the money to complete the drive apparatus. The thing was built of plywood and could not conceivably lift off the ground, but a mob wrecked his house, burned the puerile "spaceship" and would have lynched its builder if they'd thought to look in a cellar vegetable closet. Other crackpots who were more sensitive to public feelings announced the picking up of messages addressed to the distant Something. The messages, said this second class of crackpot, were reports from spies who had been landed on Earth from flying saucers during the past few decades. They did not explain how they were able to translate them. A rush of flying-saucer sightings followed inevitably—alleged to be landing-parties from M-387—and in Peoria, Illinois, a picnicking party sighted an unidentified flying object shaped like a soup spoon, the handle obviously being its tail. Experienced newspapermen anticipated reports of the sighting of unidentified flying objects shaped like knives and forks as soon as somebody happened to think of it.

Sandy called a conference on the subject of security. She did not look well, nowadays. She worried. Other people thought about the messages from space, but Sandy had to think of something more concrete. Six months earlier, the construction going on within a plaster of Paris mould would have been laughed at, tolerantly, and some hopeful people might have been respectful about it. But now it was something utterly intolerable to public opinion. Newspapers who'd lost circulation by talking sanely about space travel now got it back by denouncing the people who'd answered the first broadcast. And naturally, with the whole idea of outer space agitatedly disapproved, everybody connected with it was suspected of subversion.

"A reporter called up today," said Sandy. "He said he'd like to do a feature story on Burke Development's new research triumph—the new guided missile that flew thirty miles and froze everything around where it landed. I said it fell out of an aeroplane and the last completed project was for Interiors, Inc. Then he said that he'd been talking to one of Mr. Holmes' men and the man said something terrific was under way."

Burke looked uneasy. Holmes said uncomfortably, "There's no law against what we're building, but somebody may introduce a bill in Congress any day."

"That would be reasonable under other circumstances. There's a time for things to be discovered. They shouldn't be accomplished too soon. But the time for the ship out there is right now!" Burke said.

Pam raised her eyebrows. "Yes?"

"Those signals have to be checked up on," explained Burke. "It's necessary now. But it could have been bad if our particular enterprise had started, say, two years ago. Just think what would have happened if atomic fission had been worked out in peacetime ten years before World War Two! Scientific discoveries were published then as a matter of course. Everybody'd have known how to make atom bombs. Hitler would have had them, and so would Mussolini. How many of us would be alive?"

Sandy interrupted, "The reporter wants to do a feature story on what Burke Development is making. I said you were working on a bomb shelter for quantity production. He asked if the rocket you shot off through the construction-shed wall was part of it. I said there'd been no rocket fired. He didn't believe me."

"Who would?" asked Holmes.

"Hmmmmm," said Burke. "Tell him to come look at what we're doing. The ship can pass for a bomb shelter. The wall-garden units make sense. I'm going to dig a big hole in the morning to test the drive-shaft in. It'll look like I intend to bury everything. A bomb shelter should be buried."

"You mean you'll let him inside?" demanded Sandy.

"Sure!" said Burke. "All inventors are expected to be idiots. A lot of them are. He'll think I'm making an impossibly expensive bomb shelter, much too costly for a private family to buy. It will be typical of the inventive mind as reporters think of it. Anyhow, everybody's always willing to believe other people fools. That'll do the trick!"

Pam said blandly, "Sandy and I live in a boardinghouse, Joe. You don't ask about such things, but an awfully nice man moved in a couple of days ago—right after that shaft got away and went flying thirty miles all by itself. The nice man has been trying to get acquainted."

Holmes growled, and looked both startled and angry when he realized it.

Pam added cheerfully, "Most evenings I've been busy, but I think I'll let him take me to the movies. Just so I can make us all out to be idiots," she added.

"I'll make the hole big enough to be convincing," said Burke. "Sandy, you make inquiries for a rigger to lift and move the bomb shelter into its hole when it's ready. If we seem about to bury it, nobody should suspect us of ambitions they won't like."

"Why the hole, really?" asked Sandy.

"To put the shaft in," said Burke. "I've got to get it under control or it won't be anything more than a bomb shelter."

Keller, the instrument man, had listened with cheerful interest and without speaking a word. Now he made an indefinite noise and looked inquiringly at Burke. Burke said, explanatorily, "The shaft seems to be either on or off—either a magnet that doesn't quite magnetize, or something that's hell on wheels. It flew thirty miles without enough power supplied to it to make it quiver. That power came from somewhere. I think there's a clue in the fact that it froze everything around where it landed, in spite of traveling fast enough to heat up from air-friction alone. I've got some ideas about it."

Keller nodded. Then he said urgently, "Broadcast?"

Burke frowned, and turned to Sandy. "That's part of the broadcast from space that changes—is it still changing?"

"Still changing," said Sandy.

"I didn't think to ask you to keep a check on that. Thanks for thinking of it, Sandy. Maybe someday I can make up to you for what you've been going through."

"I doubt it very much," said Sandy grimly. "I'll call the reporter back."

She waited for them to leave. When they'd gone, she moved purposefully toward the telephone.

Pam said, "Did you hear that growl when I said I'd go to the movies with somebody else? I'm having fun, Sandy!"

"I'm not," said Sandy.

"You're too efficient," the younger sister said candidly. "You're indispensable. Burke couldn't begin to be able to put this thing through without you. And that's the trouble. You should be irresistible instead of essential."

"Not with Joe," said Sandy bitterly.

She picked up the telephone to call the newspaper. Pam looked very, very reflective.

There was a large deep pit close by the plaster mould when the reporter came next afternoon. A local rigger had come a little earlier and was still there, estimating the cost for lifting up the contents of the mould and lowering it precisely in place to be buried as a bomb shelter under test should be. It was a fortunate coincidence, because the reporter brought two other men who he said were civilian defense officials. They had come to comment on the quality of the bomb shelter under development. It was not too convincing a statement.

When they left, Burke was not happy. They knew too much about the materials and equipment he'd ordered. One man had let slip the fact that he knew about the very expensive computer Burke had bought. It could have no conceivable use in a bomb shelter. Both men painstakingly left it to Burke to mention the thirty-mile flight of a bronze object which arrived coated with frost of such utter frigidity that it appeared to be liquid-air snow instead of water-ice. Burke did not mention it. He was excessively uneasy when the reporter's car took them away.

He went into the office. Pam was in the midst of a fit of the giggles.

"One of them," she explained, "is the nice man who moved into the boardinghouse. He wants to take me to the movies. Did you notice that they came when it ought to be my lunchtime? He asked when I went to lunch ..."

Holmes came in. He scowled.

"One of my men says that one of those characters has been buying him drinks and asking questions about what we're doing."

Burke scowled too.

"We can let your men go home in three days more."

"I'm going to start loading up," Holmes announced abruptly. "You don't know how to stow stuff. You're not a yachtsman."

"I haven't got the shaft under control yet," said Burke.

"You'll get it," grunted Holmes.

He went out. Pam giggled again.

"He doesn't want me to go to the movies with the nice man from Security," she told Burke. "But I think I'd better. I'll let him ply me with popcorn and innocently let slip that Sandy and I know you've been warned that bomb shelters won't find a mass market unless they sell for less than the price of an extra bathroom. But if you want to go broke we don't care."

"Give me three days more," said Burke harassedly.

"Well try," said Sandy suddenly. "Pam can fix up a double date with one of her friend's friends and we'll both work on them."

Burke frowned absorbedly and went out. Sandy looked indignant. He hadn't protested.

Burke got Holmes' four workmen out of the ship and had them help him roll the bronze shaft to the pit and let it down onto a cradle of timbers. Now if it moved it would have to penetrate solid earth.

The most trivial of computations showed that when the bronze shaft had flown thirty miles, it hadn't done it on the energy of a condenser shorted through its coils. The energy had come from somewhere else. Burke had an idea where it was.

Presently he verified it. The cores and windings he'd adapted from a transparent hand-weapon seen in an often-repeated dream—those cores and windings did not make electromagnets. They made something for which there was not yet a name. When current flows through a standard electromagnet, the poles of its atoms are more or less aligned. They tend to point in a single direction. But in this arrangement of wires and iron no magnetism resulted, yet, the random motion of the atoms in their framework of crystal structure was coÖrdinated. In any object above absolute zero all the atoms and their constituent electrons and nuclei move constantly in all directions. In such a core as Burke had formed and repeated along the shaft's length, they all tried to move in one direction at the same time. Simultaneously, a terrific surge of current appeared in the coils. A high-speed poleward velocity developed in all the substance of the shaft. It was the heat-energy contained in the metal, all turned instantly into kinetic energy. And when its heat-energy was transformed to something else, the shaft got cold.

Once this fact was understood, control was easy. A single variable inductance in series with the windings handled everything. In a certain sense, the gadget was a magnet with negative—minus—self-inductance. When a plus inductance in series made the self-inductance zero, neither plus nor minus, the immensely powerful device became docile. A small current produced a mild thrust, affecting only part of the random heat-motion of atoms and molecules. A stronger current produced a greater one. The resemblance to an electromagnet remained. But the total inductance must stay close to zero or utterly violent and explosive forward thrust would develop, and it was calculable only in thousands of gravities.

Burke had worked for three weeks to make the thing, but he developed a control system for it in something under four hours.

That same night they got the bronze shaft into the ship. It fitted perfectly into the place left for it. Burke knew now exactly what he was doing. He set up his controls. He was able to produce so minute a thrust that the lath-and-plaster mould merely creaked and swayed. But he knew that he could make the whole mass surge unstoppably from its place.

Holmes sent his workmen home. Sandy and Pam went to the movies with two very nice men who pumped them deftly of all sorts of erroneous information about Burke and Holmes and Keller and what they were about. The nice men did not believe that information, but they did believe that Sandy and Pam believed it. For themselves, the combination of an object made by Burke which flew thirty miles plus the presence of Holmes, who built plastic yachts, and the arrival of Keller to adjust instruments of which they had a complete list—these things could not be overlooked. But they did feel sorry for two nice and not over-bright girls who might be involved in very serious trouble.

Holmes and Burke installed directional controls, wiring, recording instruments, etc. Stores and water and oxygen, for emergency use only, went into the lath-and-plaster construction. Holmes took a hammer and chisel and painstakingly cracked the mould so that the top half could be lifted off, leaving the bottom half exposed to the open air and sky.

Then the broadcast from space cut off. It had been coming continuously for something like five weeks; one sharp, monotonous note every two seconds, with a longer, fluting broadcast every seventy-nine minutes. Now a third, new message began. It was yet another grouping of the musical tones, with a much longer interval of specific crackling sounds.

Keller had adjusted every instrument and zestfully retested them over and over. Burke asked him to see if the third space message compared in any way with the second. Keller put them through a hook-up of instruments, beaming to himself, and the answer began to appear.

Newspapers burst into new headlines. "Ultimatum from Space" they thundered. "Threats from Alien Space Travelers." And as they presented the situation it seemed believable that the third message from the void was a threat.

The first had been a call, requiring an answer. When the answer went out from Earth, a second message replaced the call. It contained not only flute tones which might be considered to represent words, but cracklings which might be the equivalent of numbers. The continuous beepings between repetitions of the second message were plainly a directional signal to be followed to the message source.

In this context, the newspapers furiously asserted that the third message was a threat. The first had been merely a summons, the second had been a command to repair to the signaling entities, and the third was a stern reiteration of the command, reinforced by threats.

The human race does not take kindly to threats, especially when it feels helpless. In the United States, there was such explosive resentment as to require spread-eagle oratory by all public figures. The President declared that every space missile in store had been fitted with atomic-fusion warheads and that any alien spacecraft which appeared in American skies would be shot down immediately. Congress reported out of committee a bill for rocket weapons which was stalled for six days because every senator and representative wanted to make a speech in its favor. It was the largest appropriation bill ever passed by Congress, which less than five weeks before had cut two hundred millions out of a guided-missile-space-exploration budget.

And in Europe there was frenzy.

For Burke and Holmes and Sandy and Pam and the smiling, inarticulate Keller, the matter was deadly serious. Fury such as the public felt constituted a witch-hunt in itself. Suspicious private persons overwhelmed the FBI and the Space Agency with information about characters they were sure were giving military secrets to the space travelers on M-387. There were reports of aliens skulking about American cities wearing luxuriant whiskers and dark glasses to conceal their non-human features. Artists, hermits, and mere amateur beard-growers found it wise to shave, and spirit mediums, fortunetellers and, in the South, herb doctors reaped harvests by the sale of ominous predictions and infallible advice on how to escape annihilation from space.

And Burke Development, Inc., was building something that neither Civilian Defense nor the FBI believed was a bomb shelter.

The three days Burke had needed passed. A fourth. He and Holmes practically abandoned sleep to get everything finished inside the plaster mould. Keller happily completed his graphs and took them to Burke. They showed that the cracklings, which presumably meant numbers, had been expanded. What they said was now told on a new scale. If the numbers had meant months or years, they now meant days and hours. If they had meant millions of miles, they now meant thousands or hundreds.

Burke was struggling with these implications when there was a tapping at the air-lock, through which all entry and egress from the ship took place. Holmes opened the inner door. Sandy and Pam crawled through the lock which lay on its side instead of upright. Sandy looked at Burke.

Pam said amiably, "We figured the job was about finished and we wanted to see it. How do you fasten this door?"

Holmes showed her. The vessel that had been built inside the mould did not seem as large as the outside structure promised. It looked queer, too, because everything lay on its side. There were two compartments with a ladder between, but the ladder lay on the floor. The wall-gardens looked healthy under the fluorescent lamps which kept the grass and vegetation flourishing. There were instrument dials everywhere.

Sandy went to Burke's side.

"We're all but done," said Burke tiredly, "and Keller's just about proved what the signals are."

"Can we go with you?" asked Sandy.

"Of course not," said Burke. "The first message was a distress call. It had to be. Only in a distress call would somebody go into details so any listener would know it was important. It called for help and said who needed it, and why, and where."

Pam turned to Holmes. "Can that air-lock be opened from outside?"

It couldn't. Not when it was fastened, as now.

"Somebody answered that call from Earth," said Burke heavily, "and the second message told more about what was wrong. The clickings, we think, are numbers that told how long help could be waited for, or something on that order. And then there was a beacon signal meant to lead whoever was coming to help to that place."

Keller smiled pleasantly at Pam. He made an electrical connection and zestfully checked the result.

"Now there's a third message," said Burke. "Time's running out for whoever needs whatever help is called for. The clickings that seem to be numbers have changed. The—what you might call the scale of reportage—is new. They're telling us just how long they can wait or just how bad their situation is. They're saying that time is running out and they're saying, 'Hurry!'"

There was a thumping sound. Only Sandy and Pam looked unsurprised. Burke stared.

Sandy said firmly, "That's the police, Joe. We've been going to the movies with people who want to talk about you. Yesterday one of them confided to us that you were dangerous, and since he told us to get away from the office, we did. There might be shooting. He tipped us a little while ago."

Burke swore. There were other thumpings. Louder ones. They were on the air-lock door.

"If you try to put us out," said Sandy calmly, "you'll have to open that door and they'll try to fight their way in—and then where'll you be?"

Keller turned from the checking of the last instrument He looked at the others with excited eyes. He waited.

"I don't know what they can arrest you for," said Sandy, "and maybe they don't either, unless it's unauthorized artillery practice. But you can't put us out! And you know darn well that unless you do something they'll chop their way in!"

Burke said, "Dammit, they're not going to stop me from finding out if this thing works!"

He squirmed in a chair which had its base firmly fastened to a wall and began to punch buttons.

"Hold fast!" he said angrily. "At least we'll see...."

There were loud snapping sounds. There were creakings. The room stirred. It turned in a completely unbelievable fashion. Violent crashings sounded outside. Abruptly, a small television screen before Burke acquired an image. It was of the outside world reeling wildly. Holmes seized a hand-hold and grabbed Pam. He kept her from falling as a side wall became the floor, and what had been the floor became a side wall, with the ceiling another. It seemed that all the cosmos changed, though only walls and floors changed places.

Suddenly everything seemed normal but new. The surface underfoot was covered with a rubber mat. The hydroponic wall-garden sections were now vertical. Burke sat upright, and something over his head rotated a half-turn and was still. But it became coated with frost.

More crashes. More small television screens acquired images. They showed the office of Burke Development, Inc., against a tilted landscape. The landscape leveled. Another showed the construction shed. One showed cloud formations, very bright and distinct. And two others showed a small, armed, formidable body of men instinctively backing away from the outside television lens.

"So far," said Burke, "it works. Now—"

There was a sensation as of a rapidly rising elevator. Such a sensation usually lasts for part of a second. This kept on. One of the six television screens suddenly showed a view of Burke Development from straight overhead. The buildings and men and the four-acre enclosure dwindled rapidly. They were very tiny indeed and nearly all of the town was in the camera's field of vision when a vague whiteness, a cloud, moved in between.

"The devil!" said Burke. "Now they'll alert fighter planes and rocket installations and decide that we're either traitors or aliens in disguise and better be shot down. I think we simply have to go on!"

Keller made gestures, his eyes bright. Burke looked worried.

"It shouldn't take more than ten minutes to get a Nike aloft and after us. We must have been picked up by radar already.... We'll head north. We have to, anyhow."

But he was wrong about the ten minutes. It was fifteen before a rocket came into view, pouring out enormous masses of drive-fumes. It flung itself toward the ship.