This story originally appeared in the Young Adult science fiction anthology Universe Ahead, co-edited by me and Rick Roberson, which has long been out of print. It was published in 1975, when Rick was a college student; he was more familiar with SF short stories than I, and I had asked him to choose some that young people without previous background in science fiction would enjoy. I hadn’t planned to write one myself, but at the last minute, when we were still lacking a suitable story about interstellar exploration that we could get the rights to, we needed to fill the gap.

The story has a history that may interest readers of my novels. Though I wrote most of it, the idea for it was originated by Rick. He first suggested it to me when I was working on my 1974 nonfiction book The Planet-Girded Suns. After reading an early version of the chapter about interstellar radio communication, Rick posed a question, concluding, “Maybe this would make a good story...” That was his way of calling my attention to an inconsistency at the point in the book where I related current scientific views of interstellar communication to the opinion about highly evolved alien civilizations expressed in my novels, one that perhaps might affect my opinion itself. After some weeks of correspondence with him, I resolved the problem; between the two of us we developed some speculations that eliminated it, and that in terms of what scientists had then written, seemed reasonable.

I did not have room to explain these speculations in The Planet-Girded Suns; I simply added a comment about “complications not mentioned in the novels” to a footnote. However, I felt that the complications are worth considering. Though in the beginning I didn’t intend to actually write a story about them, I decided that this book would be a good place to put one. I’d never published a short story before; my ideas for fiction usually work out better as novels—but in this story many of Rick’s ideas were included. Interstellar radio communication was (and still is) a timely subject, and it seemed to me that our thoughts about it should be passed on to our readers.

Science fiction often does deal with timely subjects—but there is always the possibility that science itself will catch up with fiction sooner than is anticipated. That was what happened in this case. In 1974, a few weeks before Universe Ahead went to press, scientists announced that a radio message had just been transmitted from Earth in the direction of the globular star cluster M13, about 25,000 light years away. That affected some of the underlying premises of this story. It could no longer be said that civilizations normally do not attempt to send greetings to other civilizations before they have developed the ability to travel between solar systems. Still, despite my concern over the implications of then-current news reports, our editor agreed that that the basic ideas in the story weren’t actually disproven. And since then, according to the SETI Institute, only “a few, mostly symbolic, intentional messages” have been transmitted, a fact lending support to our original assumption that in view of the centuries astronomers would have to wait for replies to such messages, there will never be much interest in funding them.

I do not know if my belief about contact with civilizations more advanced than Earth’s will prove valid in the times to come, but whether it does or not, thinking about the issue is surely important to our view of the universe.

And she’d never intended to board another, exobiologist though she was. Why am I here? Ardith asked herself, turning wearily back to the cramped compartment that served as ship’s library. Why did I come when I’d already decided to resign from the Exploration Corps and take the professorship on LaLande VI? I don’t really expect to find anything that will make a difference—do I?

Still, for the first time, after all the empty years of man’s searching, there had been a Message.

Radio astronomers had started listening for interstellar messages three centuries back, in the 1960s, They had believed that sentient races elsewhere in the universe must surely be transmitting, for purposes of their own if not in a deliberate effort to get in touch with other beings like themselves. Many scientists had been convinced that such an effort was inevitable for a civilization advanced enough to be able to afford the power output, and according to statistics, advanced civilizations should far outnumber those at Earth’s level or below. There was a real expectation of establishing communication with those civilizations, and of learning from them ways to solve the seemingly-insoluble problems that plagued Earth. Yet failing that, science had reasoned, it should at least be possible to obtain evidence of alien peoples’ existence; if any were broadcasting into space, Earth’s technology could detect them.

Time had passed. No messages had come, or indeed artificial signals of any sort. And, gradually, optimism had waned; it had begun to seem that the statistics must have lied. It had been said that civilizations didn’t survive long enough for there to be much chance of detecting their radio broadcasts, or that they abandoned technology, or that intelligent life of other worlds wasn’t in any way human in its psychology. It had for a while been thought that the universe was as hostile to life as early twentieth-century scientists had maintained—that theories suggesting an abundance of life must be flawed. Once interstellar travel began, that proved untrue. The universe was full of life. Ardith herself had studied it in a dozen different solar systems. But nowhere within the areas visited was it as advanced as on Earth. There were primitive forms and in some cases, sentient species; but no highly-evolved ones. No waiting galactic supercivilization. Not even a culture that had progressed much past the Stone Age. A thorough search of Earth’s region of the galaxy would require travel to many thousands of stars, so in the absence of signals, mankind was resigned to being alone.

So we go on, Ardith thought, spreading our colonies from system to uninhabited system, leaving the few inhabited ones for their natives to someday develop. And what good is it? It was exciting, once: it was the Big Dream, the long-awaited destiny, the ultimate challenge. To fly among the stars was man’s great hope fulfilled. In the beginning I felt all those things—even I, born a hundred years too late. If I’d been born in the Dawn Age of interstellar travel would things have been different? Would I not have out grown the dream? Would I still see new territory to explore?

She glanced around the compartment at the men and women gathered there, some reading, others talking quietly; and she wondered how many of them shared her depression. Lately it had all seemed very pointless. You lost track of the solar systems after a while. You started questioning whether colonization of another one, or even scientific analysis of another one, could lead anywhere ... though you were not really sure where you wanted it to lead.

I’m old, she realized. I’m not yet thirty, and already I’m old! There had been a time when she wouldn’t have considered settling permanently on any planet, not even a newly-opened one like LaLande VI. She would have rejected the offer of the professorship; she would not have begun to suspect that her career, and possibly someday a family, might be all she could expect from life. Once, no opportunity would have outshone her vision of something to be sought beyond the next star. Did it now? Or was it merely that she’d lost the vision?

She’d convinced herself that she didn’t care, that it had been a childish dream anyway, as philosophers said mankind’s dream of meeting advanced aliens was childish. Then the Message arrived, and it had ruined her hard-won indifference.

There was no mistaking the artificial origin of the Message. The signals received were classic in format, the format predicted three hundred years ago by the early radio astronomers: binary impulses that could be decoded to form a diagram. The diagram was of the same kind enthusiasts had always used to illustrate the ease of communicating with an alien intelligence. It contained universal statements of mathematics and physics. It portrayed the solar system of its source. And it showed, as a stick figure, a being definitely humanoid in shape.

The Message was repeated at regular intervals over a period of twelve days. Then it stopped. But no scientist doubted that the content of the recordings had been designed as a greeting. Mankind was not alone among reachable technological civilizations after all. Nor was man the most advanced species in Earth’s part of the universe ... because the Message had been in transit nearly a thousand years. It had come from a star nearly a thousand light-years away. If its senders had high-power transmitters a thousand years ago, what had they achieved by now?

Or had they survived to achieve anything?

If they had, it was argued—if any civilization that advanced existed so relatively close—Earth should have heard from them long ago. They would have faster-than-light ships, too; they’d have been using them for centuries. Perhaps not enough ships to send everywhere. Yet the Message had not been sent everywhere, either. It had not been broadcast to all of space; it had been beamed directly to Earth, The beam was so narrow that it had not been received in colonized solar systems even as near as Alpha Centauri. That was the most puzzling thing about it. The odds were incredible that by accident, Earth should have been singled out to receive the Message, a Message sent not only before man’s own initial radio waves could have reached its source, but long before the voyage of Columbus.

Perhaps it was not by accident. Perhaps the senders had faster-than- light travel a thousand years back, and had seen which of the countless solar systems within range were developing civilizations; they might have beamed signals timed to arrive when those civilizations were able to send ships of their own. Maybe they did not plan to pass near Earth again. Earth might not be that important to them. They too might wonder if still another world was worth the trouble, Ardith thought sadly.

She, like the other members of the expedition, had speculated and debated and had finally given up in frustration; though the various theories about the Message were complex, there was a limit to the length of time you could spend going over the same ground. Yet you couldn’t concentrate on other work, either. If you had no shipboard duties—and most of the scientists did not—then you could only sit and think, or pretend to read, or make small talk ... and slowly go crazy. We are in limbo, she thought, as the ship is in limbo while outside normal space. This should be the most thrilling trip of our lives, of mankind’s history, even—and it isn’t! It isn’t! It’s as if we’ve lost something ...

She sat down, pressing her hands to her forehead, fighting the headache she knew would come. Headaches had been frequent enough these past weeks. At least there were only a few hours left until deceleration. Before long speculation would have ended; she would know. Know what? Ardith’s mind persisted. That they died while our civilization was young, that all that is left are ruins to excavate? Or that they live, so that in them we will see there is nothing new ahead of us?

From the contour chair next to Ardith, Fred Liang smiled at her. He was a young man, perhaps five years younger than herself, but of the astronomers aboard the one she’d found most congenial. Most of the rest were quite sure what they’d find at the destination solar system, at any rate as far as its physical aspects went; their opinions were strong even about the rationale behind the Message. Fred had an open mind.

“Nerves?” he asked, not needing any more words, though it wasn’t a thing people commonly spoke of.

Ardith nodded. “I was—wondering why I came.”

“We’re all afraid, you know.”

“You, Fred?” It surprised her; he was too young to be afraid.

“Not of—well, not physically,” he explained hastily.

“Of course not.” None of them worried about the Others being hostile, or treating them as lab specimens—though it occurred to Ardith suddenly that if you wanted to capture specimens, you sometimes imitated calls that they would heed. Like the mating calls of insects. She laughed; it was a good mask for deeper fears.

But Fred wasn’t afraid in the same way she was; he had not yet lost his sense of excitement. Nor did he, like many of Earth’s scientists, have mixed feelings about encountering a race that had achieved all they themselves could achieve long ago in the distant past—a people whose stature might make man’s own efforts meaningless. “What is it, then, Fred?” Ardith asked, lapsing into soberness.

“I’m afraid I’m not good enough,” he confessed. “That I won’t meet the—the admission standards, so to say.”

“You will if any of us do.” She regarded him thoughtfully. “You picture Earth as a—a candidate? I suppose you’ve been talking to Jacob.”

“Yes, but I always did feel we’re coming as children, to be taught. Jacob—he doesn’t believe that. I don’t know what he believes now; our having received the Message runs counter to his theory. And he admits it.”

“Which is more than can be said of certain other people! I like him for that.” Jacob Stromberg was an anthropologist, and a distinguished one. There had been no question about his qualifications for leading the expedition’s contact team. His accepting the post had been odd, however, for throughout his career Jacob had insisted that it was harmful to primitive peoples to be contacted by more advanced ones. He’d been instrumental in upholding the non-interference policy with regard to the extraterrestrial Stone Age cultures observed by man; he had maintained that being different species, they needed to evolve at their own speed. And with strict consistency he’d applied the principle both ways: in his view, no superior civilization would contact mankind by interstellar radio or by any other means. Jacob had thought it very natural that three hundred years of listening had yielded no results, though he favored the early statistics that said such civilizations were prevalent. The Message must have been a blow to him.

“I don’t quite see why his theory was affected,” Ardith admitted. “I’d think he would merely be afraid that this contact is going to harm us. After all, we don’t know the Others were trying to contact worlds less advanced than theirs—not unless we assume they knew of our existence. They could have been searching for superiors, with the idea that if it was harmful their superiors wouldn’t answer.”

“You can’t place the whole burden of the decision on the superior civilization,” Fred pointed out. “Because if some worlds do transmit, then space is full of their old messages sent before they knew it was harmful. Nothing can get rid of the old radio trails, traveling on forever at the speed of light; and the farther from the source they are when some world picks them up, the bigger the evolutionary gap between senders and receivers. The damage is already done, Ardith, if contact is bad for us. We’ve already had contact with them; everybody on Earth knows how far ahead of us they are.”

Ardith thought of friends she’d left, friends who were half-hoping that the expedition would bring back answers to culminate their research ... and half-hoping that it wouldn’t. She shivered. “Jacob must be more scared than any of us; he’s so sure civilizations can’t skip stages.”

“He’s worried, all right. I’ve watched his face when he thought no one was looking.”

“He wouldn’t—that is, there’s no chance of his deciding to—”

“Sabotage the mission?” Fred shook his head. “Jacob is too honest, He won’t hide truth; he’s convinced that mankind can’t ever benefit from denying reality. Besides, it wouldn’t solve anything for him. What bothers him isn’t so much the thought that we might get hurt as that the universe isn’t set up with safeguards.”

“Good Lord, Fred. Jacob’s too bright to suppose that the universe has ever been safe.”

Fred hesitated. “Of course he is. Like I said, he knows we could get hurt. We could have blown ourselves up before we outgrew war, too. Or the sun might go nova. But those he considers exceptions—I mean, they don’t happen to most sentient species in the normal course of events; they’re cases of something going wrong. Whereas if sending interstellar radio greetings is harmful, and it’s done before civilizations are mature enough to know better, then sooner or later almost every world would be affected.”

“But he could have figured that out before we ever got the Message,” protested Ardith.

“He had a safeguard theory, though, one that explained why the danger should be negligible. Till now, the evidence for it has built up year by year; the Message is the first negative sign there’s been. It could be a freak, but—”

“But statistically, that’s an unscientific assumption,” Ardith agreed. “Every step of scientific progress has shown that it’s more valid to assume Earth isn’t freakish. In fact in the fields where we have data enough, we’ve found that there are no freaks; there are only patterns.”

“Yes, And Jacob thought he saw a pattern, but the Message doesn’t fit into it.”

“I wonder.” All this was so fruitless, Ardith was thinking. These eternal discussions were so tiring, when they couldn’t get anywhere—yet you couldn’t turn your mind off. “Fred,” she asked, “has Jacob ever considered there being a point when contact’s good? I mean ... when there’s no other challenge left for a civilization: when we’ve abolished war and poverty and totalitarianism—all the evils our society’s gotten rid of these past three centuries—and when establishing colonies is so routine. We weren’t given answers to those problems. We found them on our own. And sometimes ... I wish I’d lived while we were still finding them.”

“You’re saying contact with other civilizations may come next?”

“Why not? Something has to. Or we’ll ... lose interest. Give up from sheer boredom. I think what scares me most is the idea that the Others may have done that. Seeing they have would be worse than finding them far ahead, whatever Jacob may say.”

“I don’t think he’d say you’re wrong,” Fred replied gravely, after a long pause. “I haven’t heard him speak of eventual contact; I’m not sure if he believes there’s a time for it. Yet he came on this ship, didn’t he?”

Late in the night, by its Earth-standard clock, the ship emerged into normal space and began to decelerate. Ahead was the star Omega, so called by the expedition because it was too dim in Earth’s sky to have been formerly known by anything but a catalog number. Ardith did not see it; she was sleeping. But while she slept she began to dream, and the dream was of vast luminous cities and unnamed sensations and other things she could not describe or remember.

She woke in a mood unlike her customary one; for a few seconds she imagined herself back on the first starship she’d traveled in, thinking, There are five glorious new worlds out there, worlds mankind has never set foot on ... But how odd, she reflected, sitting up and reaching for her hairbrush. There hadn’t been five worlds in that first new system she had explored; there’d been eight, of which only two weren’t gaseous. As for the Omegan system, data in the Message had specified that there were eleven. That could not be verified, though, until the instrument readings were in.

When she went to breakfast she found everyone in a state of stunned dismay. The initial instrument readings showed no planets at all.

To be sure, the ship was still far out; it hadn’t been safe to calculate the coordinates too close for such a long jump, and it would be necessary to make the final approach below the speed of light. But at this distance planets should be easily detectable. Ardith joined the crowd by the viewport, her heart lifting at the sight of stars spangled against the dark expanse, so welcome after the days of featureless void. The constellations were unfamiliar here, a thousand light-years from home. Even large planets could not have been identified by the naked eye. Telescopic observation, however, should have found them; the computer should have charted the whole system by this time.

The day passed. Fred Liang and the other astronomers stayed in the observatory; Ardith did not see them. Morale among the rest of the staff was at low ebb, People were too baffled even to discuss the situation. Inexplicably, her own spirits remained high. She could not account for it. Am I thinking that if there are no planets my worst fear can’t be realized? she wondered. But then neither can my hope, such hope as it is. The universe will seem emptier than ever! She did not feel empty. She felt more on the verge of discovery than at any time during the journey.

For the others the reverse seemed true. Most of them had anticipated immediate radio contact with the Omegan civilization, yet the ship’s signals brought no response. “Perhaps the Omegans no longer use radio,” people said, “still they’d listen for a reply to the Message! They’d monitor that frequency and answer us—” What people did not say, at least not aloud, was that the Omegans were evidently gone. Sometime during the thousand-year time lag, they either had been wiped out or had migrated. What else was there to think?

That night Ardith dreamed again as soon as she fell asleep. It seemed that she was free in space, without gravity, without even a spacesuit to isolate her from the void; but it was not a void. It was filled with light and sound and a nameless presence that she knew not through her senses, but through faculties she’d never before possessed. In the dream this seemed natural. She felt no surprise, nor any trace of fear: she was flooded with joyous anticipation. But what she anticipated she did not yet know.

The impressions of the dream became less vague. Gradually they crystallized, focused, until she was in the midst of spinning globes. They spun in starred blackness, though she herself was enveloped in the warmth of sunlight. How could the solar system have been thought planetless? There were many planets, some circled by moons, and all were of surpassing beauty. But five stood out; they sang to her of things past imagining—it was if her senses were transformed. She heard colors, patterns, indescribable concepts. Space was not silent any longer ...

Ardith woke abruptly. For an instant her elation remained; then she was moved to tears of frustration and regret. Why had she been torn back from the place where there’d been something to look forward to?

In the morning, after orbit around Omega was established, she found Fred with Jacob Stromberg, weary-eyed, exhausted from hours of uninterrupted work. “There’s no reasonable explanation,” he was telling Jacob. “The Omegans might be gone, but their planets couldn’t be. Planets can’t just disappear.”

“Maybe—maybe they blew them up,” Ardith ventured, voicing what she knew many people suspected.

“All the planets in their system? And into dust, not mere fragments? There would be evidence! Even if they could do such a thing, there’d still be dust. We’re close enough now to detect it. Anyway, that’s not the main problem. We’d expect planets here if there had been no Message at all, simply from the characteristics of the sun.”

Jacob frowned. “Are you saying astronomical theory isn’t consistent with a sun like Omega being planetless?”

“I’m saying we’ve got to junk all the theory about planetary formation we’ve got,” Fred stated flatly, “theory that’s held up in every solar system man has visited. Of course only a small area of the galaxy has been explored—but the same physical laws apply everywhere.”

“Yes, but ... well, I’m no astronomer. Still, rejecting a fundamental theory sounds a bit drastic.”

Shrugging, Fred countered, “What do you do in anthropology when the theories don’t fit the data?”

“We may not have all the data here,” Jacob declared.

“The instruments have been checked and rechecked and cross-checked about fifty times.”

“I can guess what you’re thinking,” Ardith said to Jacob, feeling a strange, cold thrill. “The Others—the Omegans—could be influencing the readings.”

“Influencing our instruments?” demanded Fred. “That’s impossible. The readings for everything else are okay. What we’ve learned about this sun itself matches data from Earth’s telescopes. We use the same equipment for different purposes, you see—”

“Fred,” argued Jacob, “I don’t say the instruments themselves could be affected; you know more about that than I. But we all know basic scientific method. You tell us the theories about presence of planets apply to every known solar system but this. There’s just one other way in which this system differs: it was the source of the Message. It was once, at least, the home of a technological civilization. What are the odds against the only two variables being unrelated?”

“You have a point,” Fred admitted. “We’d be fools to write it off as random chance. No gambler would take such odds, that’s for sure.”

“Which means the Omegans either did something with their planets and moved on, or ... they’re hiding from us. They have a way to shield their worlds from detection.”

“Why all their worlds?” Ardith asked. “Why not just the five inhabited ones, so astronomical theory wouldn’t seem invalid?”

“That wouldn’t work; we could tell from the orbits of the others—” Fred broke off. They stared at each other. She had said five...

“I don’t know why that slipped out,” she murmured, embarrassed out of all proportion to the incident. “I had some silly dream last night; there were planets in it.” Which was natural enough, when that was what she and everybody else had been concentrating on. Why should it impress Fred and Jacob, as it obviously did; why weren’t they laughing it off?

His frown deepening, Jacob said slowly, “That they’re shielding is most probable. I—I had hoped it would not be so.”

“But it supports your own theory!” exclaimed Fred, surprised. “If your ideas about the harm in contact are right, the Omegans would shield. They’d have learned by now that they shouldn’t have sent the Message.”

“No. You don’t understand. If messages are sent that should not be received, the safeguard theory is wholly demolished. We must either concede that or say Earth is a freak case, and the odds that it is are even longer than those we were just discussing.” Jacob smiled ruefully. “People thought it strange that I favored this expedition. Some feared I came to ensure its failure. But the truth is that I still trusted in universal safeguards, factors in the design of the universe that keep most worlds from coming to harm. And as for Earth being an exception . . . well, I bet on the alternative with the best odds.”

“There’s another alternative,” said Ardith. “Contact may be harmless to us now.” Somehow she felt surer of this than when she had mentioned it before the past nights’ dreams.

“I know,” agreed Jacob, in a tone that told her he had known and hoped for a very long time. “But if that were so, why would they shield their worlds?”

She could think of no cheerful reply. Finally she said, “Isn’t the fact that they can shield at least an indication of safeguards, as you call them?”

“Ardith, think,” put in Fred. “We crossed a thousand light-years! Suppose they discovered the shielding process only within the last century or so—it must be very advanced; our science can’t conceive of any way such a thing could be done. What about all the worlds at closer range? Besides, knowing that a race so far ahead of man exists may in itself be damaging to us.”

“I’ve never heard this safeguard theory,” she admitted. “I don’t know what it involves.”

“That’s not an official name, of course,” Jacob explained. “And it’s not actually a theory; it’s a mere hypothesis—an educated guess—though the fact Earth listened so long before receiving signals does provide some evidence. Essentially, it’s an assumption that interstellar radio greetings are never transmitted in the normal course of a civilization’s development: transmission’s just too expensive before a species is far enough along to realize that less advanced worlds’ evolution can be upset by contact. In other words, everybody listens and nobody sends. After all, Earth never transmitted any messages; a project like that couldn’t have gotten funded unless we’d received one prior to the invention of faster-than-light travel.”

“If the transmission of greetings was normal we’d have picked up broadcast signals years ago, according to statistical probability,” Fred added. “Broadcasting a general beacon is much easier than beaming to countless specific solar systems; if a civilization was trying to find what others exist, that would be the natural way of going about it. To be sure, beaming takes a lot less power. But if the destination’s so far off that one beam can reach many stars, you can’t hope for replies.”

“Then the fact that the Message was beamed to Earth selectively—”

“Might be encouraging.” Jacob nodded. “I let myself be encouraged, again because the odds of that happening by chance were so incredible. But there is always the possibility that the Omegans discovered Earth at a time when the question of whether contacting younger species does harm was controversial among them, as it still is in our own civilization. We have faster-than-light travel, and my ideas aren’t supported by all my colleagues. What, for instance, if we were to find a developing civilization near here, a thousand light-years from home—isn’t it conceivable that someone on Earth might beam a greeting to it, in case we don’t come back in a thousand years? To send a few beams is cheap; it might well be tried.”

“Or,” Ardith reflected, “there’s the possibility that some worlds may pick up signals not meant for them.”

“The chances of that are small enough to fall in the ‘freak’ class,” Fred told her. “Early radio astronomers once supposed they might eavesdrop on signals not intended as greetings at all, but we’ve never received any, and there were a lot of advances that they didn’t allow for. They figured high-level civilizations would form associations by radio instead of developing faster-than-light travel; and they even assumed a long period of local signal leakage. From Jacob’s standpoint, things look safer than they used to.”

Ardith watched Jacob’s face, feeling confused and uncomfortable. “I am not sure,” she said, “that we should want to be so safe. Do you really believe it is wrong for us to seek knowledge of higher civilizations?”

“No!” he replied intensely. “That’s a misinterpretation of everything I’ve ever stood for, Ardith. It’s never wrong for man to seek knowledge! It wasn’t wrong for radio astronomers to listen, and our mission here is vital to mankind. If what I believe about safety factors in the universe is true, we won’t find things beyond our ability to cope with—but we must keep on searching for whatever we can find. How else will we advance? It’s wrong only to force knowledge on those unready to seek it for themselves.”

“If there should be a way to—to penetrate the Omegans’ shields, then, you wouldn’t oppose it?”

“I’d be the last person on this ship to do that,” Jacob assured her. “Wait and see: if there is any chance of penetrating, I’ll fight for it ... and the rest of the staff will vote me down.”

Again, both that night and the next, Ardith dreamed so vividly that she was reluctant to come back to consciousness. But in the daytime she was not sure what she had dreamed.

Music ... like the “music of the spheres” the ancients had written about, she thought, trying to sort out the traces accessible to her. No, not music ... not even sound, perhaps, but something for which no words existed. We think in words, she realized, and that limits us. We think in terms of what we already know. There’s something here we’ve never met before...

She was torn in two. The dreams elated her; waking brought back all the anguish of losing purpose in life. Maybe there were not really five inhabited worlds in the Omegan system, she told herself; maybe she merely wished there were. Yet half the time she did not wish it; she was afraid ... afraid that the real worlds would not be like the ones of which she dreamt.

Almost everyone aboard seemed to have recovered from the initial disappointment of finding no planets; though Jacob and Fred presented the shield theory in a staff meeting, it was dismissed as fanciful by a large majority. Maybe the others have the same fear I do, Ardith found herself thinking as she talked this over with Fred. Maybe they’re afraid the Omegans have nothing worth shielding, nothing far enough from our level to be a challenge ... maybe they’d rather leave without knowing. Perhaps, if contact is harmful despite our having solved Earth’s problems, that is why. The Omegans may want to spare us the final disillusionment.

“But that’s inconsistent!” she burst out aloud.

At Fred’s puzzled look, she explained, “I was wondering what the Omegans need to conceal. According to what Jacob believes, mature civilizations don’t reveal themselves to immature ones because if they tried to spare them trouble it wouldn’t really help. If you help a butterfly out of its cocoon its wings won’t get strong, and it will die. By that reasoning, it’s understandable why they never gave us answers. But now, if the worst thing we face is finding nothing left to look for, they wouldn’t try to spare us that knowledge; it would be the next problem in sequence for us to solve.”

He appraised her, startled. “Ardith, do you honestly think there’s nothing left to look for?”

Equally startled, Ardith whispered, “No. No—not any more.” The fear drained out of her, and her heart began to race with excitement she had not felt for years. She knew. The dreams weren’t mere symbols of her own suppressed longings. They were—contact. In sleep she had already begun to penetrate the shield.

When she next slept, she lay in darkness that melted into the light of strange new perceptions. She was in space no longer. She stepped into regions belonging to the planets themselves; yet she did not walk there, or fly through their skies—she was simply aware of them, without apparent bodily contact. There was no coherence to it; she was shifted from one scene to another in the way of dreams, and always there was the singing that was not singing. She heard no melody, no words, but only voices glimmering through mist like colored flashes seen from the depths of a luminous pool. She clung to sleep, struggling to rise to the surface of the water ... .

And awakened in bitter disappointment.

Being now beyond all embarrassment, Ardith sought out Jacob Stromberg. “Yes,” he told her, “I’ve dreamed, too, and so have others—more than will ever admit it. We can’t force the issue. There must be no open discussion until each person who’s receptive is independently sure.”

“It’s a crucial phenomenon, though! It may even signify—”

Jacob sighed. “Talk to Reiko Yamada; you’ll see what I mean.”

Ardith found Reiko, a young chemist whom she didn’t know well, alone in her quarters. The girl was evidently quite upset; at the mention of dreams she wavered between defensiveness and an irrepressible eagerness to speak of them. “Look,” she said to Ardith, “I don’t claim there’s anything supernatural about it—”

“No one’s saying you do,” Ardith assured her, though she saw from Reiko’s face that some people were indeed saying that.

Reiko was convinced that five planets in the Omegan system were heavily populated. “I know they’re here— the Others,” she insisted, twisting her fingers nervously. “Dr. Gordon says it’s wish-fulfillment—”

“Gordon? I thought he was trained in parapsychology.”

“Sure he is. He calls it telepathic contagion; he treats me as if I were a carrier or something. He wants to put me under sedation at night, but I’ve refused. They are good dreams.”

“Can you remember many details about them?” Ardith asked, hoping desperately that Reiko could draw back the curtain that descended whenever she herself tried to recapture specific images.

“Not many,” Reiko confessed. “I just—well, I find knowledge in my mind. I have a rough idea of the planets’ distances from Omega, for instance, as if someone had told me.”

“You mean the Omegans talk to you?”

“No. It’s not like that. It’s more like clairvoyance; I believe I’m sensing things by myself.”

“Can you do it while you’re awake?” Ardith persisted.

“A little, now. I know what’s real and what was an ordinary dream.” She added, “I never had ESP talent before. That’s what’s so strange about it; if it were in my history, I suppose Gordon would accept it.”

Ardith pondered this. “I wouldn’t bank on that,” she said, reflecting that a parapsychologist who’d joined the expedition with the idea the Others might be telepathic ought to be fascinated by Reiko’s testimony. Also, the senior astronomers ought to have figured out the possibility of deliberately shielded planets long before Fred and Jacob had.

“Reiko,” she continued, “why did you join the Exploration Corps?” She was groping toward something she couldn’t yet define. “An exobiologist like me has to go to different worlds, but there are plenty of opportunities for chemists on Earth. Was it too crowded there, or what?”

“I didn’t grow up on Earth; I’m from the colony on Ceti IX. It wasn’t crowded and there was plenty of interesting work, but it didn’t seem enough, somehow. I thought the Corps would be different.”

“And it wasn’t.”

“You feel that too—as if there has to be more, somewhere? More even than meeting other species with high civilizations?”

“Yes. But most of the people aboard this ship don’t. Maybe they did when they were kids, but now—well, they shut it out, the way they do these dreams. They could as well be in research labs on Earth; they’d function just the same there, if not better.”

“They—oh, I don’t know how to express it—but it’s as if they can’t bear the longing.”

“You express it perfectly,” said Ardith. “What they can’t bear, they won’t acknowledge even to themselves. If Omega had been what they were picturing, a system of worlds that could be analyzed by the old rules, it would have been okay. But without the framework of those rules their lives will fall apart ... and there is something more here.”

“Something besides just seeing these five worlds and their culture,” Reiko declared positively.

“The dreams won’t show it clearly, though. We won’t know what it is if we leave without finding the worlds.”

“The Omegans can’t hide them from us, Ardith. From the machines, yes, but not from us. Nobody’s sending the dreams; we are simply—sensitive. There are millions of other sensitive minds out there, and subconsciously we feel their presence. I think ESP must be more highly developed among the Omegans than in our species so far; that’s why sensing them takes less talent than sensing other minds on Earth.”

Ardith laughed. “It’s easy to say, but the majority will not believe it; they’ll trust the instruments more than they trust themselves.”

“I know,” admitted Reiko. “We’ll be torn away, a thousand light-years back, and for the rest of our lives, jumping from solar system to solar system—colony to colony—we’ll know that we’re not getting anywhere. That we failed to follow the only forward trail.”

We can’t let it happen! Ardith thought fiercely. Yet we can’t prevent it. We’re ahead of our time, we few who believe in our own dreams.

She went to bed early that evening, hoping to dream more; but sleep would not come. Her mind would not rest: over and over it explored all the frustrating channels. This was how evolution worked, she told herself. She was a biologist; she’d studied evolution; she could apply the principles beyond the realm of biology. Always, steps forward were taken by the few, not the majority. In the fullness of time mankind might be ready for Omega. For the present, the dreams of the few would remain unfulfilled. The forward few always suffered; the first creature to crawl out of Earth’s primeval sea had no doubt found it painful to breathe air. Yet preferable to returning to the sea.

Ardith sat up in her dark cubicle, pulse pounding. What was happening to the expedition was not how evolution worked! Had that struggling creature been forced back to water when it was ready for air?

The majority of mankind had not been ready for the moon in the 1960s, yet the few who cared had managed to get men there. The majority had not been ready for the stars when the dissatisfied few had begun to colonize other solar systems. As Jacob would say, the universe had built-in safeguards. The way forward always existed. Those who chose it might suffer or fail, but they could choose it; they were not condemned to waste their lives feeling they’d been born a century too late—or too early. No species could evolve if the way were barred to the pioneers.

She wanted to cry out silently, Oh, help me, help me, whoever you are here—you Others on the bright invisible worlds that orbit this sun! Show me the way and I’ll come! I won’t be like the rest; I won’t turn my back on what the Message trail’s led us to find... but no. That was almost a prayer, and they were not gods. They couldn’t help. They wouldn’t even if they could; they were wiser now than when they had sent the Message.

Or were they?

With shaking hands she reached for her clothes, slipping into them hurriedly. Fred might still be up. She could not wait till morning to ask the question that suddenly occurred to her.

She barged into the observatory center, heedless of the two other astronomers who were sitting with Fred at a computer console. “Maybe this is stupid,” she began without preamble, “but how do we know the Message came from Omega’s solar system?”

Fred looked up, startled. “Why, because it came from precisely this direction—telescopes picked it up only when accurately focused on this star.”

“But have we any proof that it traveled a thousand years?”

“The speed of light and radio waves through space is a constant; you know that. We know we came about a thousand light-years to get here, and that’s simply another way of saying radiation from here takes that long to reach Earth.”

“Suppose something else generated the radiation, something directly in line—”

“If there were a closer solar system in direct line, we’d never have seen Omega from Earth. And if there were a farther one, Omega would have interfered with the signal waves.”

“Yes—yes, of course. But a ship, for instance. If a ship relatively near our system had been precisely in line with Omega, and had sent the Message, there’d be no way of telling the difference, would there? We couldn’t tell that the signals hadn’t actually come so far.”

“Since we can’t verify the original frequency, no,” Fred agreed. “Not unless the source was close enough to show parallax, which means very close because the beam wasn’t received outside our solar system.”

“Only a few light-years,” put in one of the men with quick interest. “We didn’t receive for long enough to detect parallax on Earth, and Mars was on our side of the sun; the distance between planets wasn’t great enough for much parallax measurement.”

“But it’s fantastic, Ardith,” Fred objected. “The odds on a ship being in exactly the right position—”

“I realize it couldn’t happen by chance.”

The older man’s face lit up. “A hoax,” he said. “It accounts for the selectivity of the destination, the tightness of the beam, everything! I wouldn’t have thought anyone in the Corps could astrogate that well, let alone a commercial cruiser; still it’s the only sensible explanation.”

“That wasn’t what I was suggesting!” exclaimed Ardith. But in the relieved expressions of Fred’s colleagues she could see that it was too late to amend her words. Unwittingly, she’d provided the safe, logical way out they’d been hunting for.

“Let’s see who we can round up,” said one of them. “I want a staff meeting the first thing tomorrow morning—there’s no point wasting any more time in orbit.” They left hurriedly, ignoring Fred as well as Ardith.

Fred looked troubled. “I’m sorry you said that in front of Ivanson,” he told her. “The hoax idea will be the clincher—not that it will alter what he was trying to do anyway. In orthodox scientific terms we’ve collected all the data we can here. Ivanson’s been pushing for a jump to the nearest similar star hoping it has no planets either; he’s rewriting planetary theory and as chief astronomer aboard, I think he’s got his eye on the Galaxy Prize. The chiefs of the biology and geology departments will support him; their people are going batty without planets to study, and they want to get moving.”

“I suppose that’s the official explanation for the dreams,” observed Ardith bitterly.

“What else?” He met her eyes. “Ardith—what were you getting at, if not a hoax?”

“I—I guess I was backing up Jacob’s safeguard idea.”

“That we’re unlikely to have gotten a message we shouldn’t have? But we did receive one—” Fred paused thoughtfully. “Oh, you mean that if we can’t prove the senders are a thousand years ahead, no damage has been done. Maybe not; still it doesn’t save Jacob’s theory. It doesn’t provide for the case of worlds receiving signals before the senders have learned to shield their own planets from detection.”

“There may not be any such cases,” declared Ardith. “Don’t you see, I’m saying he could have been right in the beginning about no harmful signals ever being transmitted! An Omegan ship could have sent the Message—recently—to bring us here.”

“Because we’re ready for contact with them? Then why shield their worlds from us?”

“Not necessarily from us; perhaps from other passersby. But also perhaps from those of us who aren’t really ready.”

“Like Ivanson.”

“And like our blind parapsychologist Gordon. Fred, suppose Jacob is right all the way. Suppose he’s even right about there being a huge hidden supercivilization, the kind imagined by twentieth-century radio astronomers—”

“In that case,” interrupted Fred, frowning, “we should have found suns like this before without visible planets. They’d be shielding many.”

“Maybe they deliberately avoided colonizing systems near Earth, at least those of stars we’d be likely to visit. There are thousands of solar systems a supercivilization could choose from; and besides, some of its member species may have environmental requirements different from ours. We’ve known all along there must be other civilizations in the galaxy, that our not finding them was a matter of the odds against stumbling on them—and the same goes for shielded systems.”

“True. A federation of species could manipulate the odds. What’s more, if a people did come across a shielded system prematurely, that wouldn’t do any harm.”

“Only for us it’s not premature,” Ardith went on, her exhilaration growing. “If there’s a supercivilization, and we’ve reached the point in our evolution when we’re to be admitted, how would contact be made? Surely the Others wouldn’t land UFOs on Earth as if they were creatures out of an old-time space opera.”

“No,” Fred agreed slowly. “The old assumptions were all wrong. They’ll never come to us; we had to come to them—in more ways than one.” Watching him, Ardith knew that he too had dreamed, and that his longing to respond to the dreams equaled her own. He cursed softly. “We came, yet we’re going to blow it.”

“Are we? I think if they’d expected everybody to react the same way, we’d have met the welcoming committee by now. Why not land their ship on Earth, if not to give us personal choice?”

“Ardith, you know what will happen if we present these theories in a staff meeting. Jacob will back us, and Reiko Yamada, and perhaps four or five others. We won’t sway the majority. The ship won’t wait to investigate.”

“We don’t need the majority, or the starship either. Just one landing craft. You’ve done some piloting, haven’t you?”

“Orbit to ground, yes. But I can’t astrogate without—”

“Without knowing where the planets are. Fred, if I’m right, Reiko can ... locate them. Can you establish an orbit once you’ve sighted a planet?”

He drew breath. “Yes. I’d like to try. It’s insane not to try when we’ve come a thousand light-years! But a landing craft can’t gather any more data than this ship’s instruments; I doubt if the Captain will authorize it.”

Ardith laughed, feeling buoyant and reckless and young again. “Who said anything about consulting the Captain?”

From the landing craft, three days later, they stared at the blazing stars—groupings they now knew well— and tried not to reckon the minutes that were passing. So little time left, Ardith thought, and if we fail we’ll have no second chance.

There were seven people aboard; Jacob had known which to talk to. Getting away unnoticed had been no problem. The Exploration Corps, being a scientific search organization, had no need to place guards on its equipment, and the idea that someone might want to make an unauthorized excursion in a landing craft had never occurred to the Captain. The landing craft bay had been deserted, as it always was while the starship was in deep space. There was no reason for anybody to go near it when no planets were thought to be close. Fred had been able to program the craft’s astrogation computer without fear of detection during the time it had taken Ardith and Jacob to enlist the others.

But a second chance was out of the question. If they docked to restore their dwindling life-support, they would not be permitted to separate again. That had been only too obvious from what had been said over the radio they’d finally turned off.

And over half the time for which their life-support was adequate had now passed.

“I don’t understand,” Reiko said wretchedly. “I know there’s a world nearby. We’re in the right area! We’ve been approaching! And still no sign—”

“We could see it with our eyes by now despite whatever keeps the instruments from picking it up,” someone protested. They had come far from the starship in the sixty hours since they’d left it; the craft was fast enough to circle Omega. They had not needed to circle, however. Reiko’s sensing ability had led them closer to the sun, but no great distance in the new orbit, before they’d all begun to know they were in range. Asleep, dreaming, they had known positively.

“We can’t guess how the shielding works,” Fred pointed out. “It’s possible that a world might be hidden from our eyes as well as from instruments.”

So much was hidden. The landing craft’s radio could not be tuned to the frequency on which the starship was signaling to the Omegans, which was of course an astronomical one, the one on which the Message had been received corrected for the presumed thousand light-years of travel to Earth; neither the starship’s call nor any possible reply to it could be detected. What else is there in the universe, still invisible, that we’ve never even imagined? wondered Ardith. Have we ever really searched? Do we know how to search? Or were we too busy founding colonies to care?

“The colonies were necessary,” Jacob said. Ardith wasn’t surprised that he’d answered unspoken thought; it had happened frequently, among all of them, these past few days.

“Necessary,” Jacob continued, “but not the real purpose of travel between the stars. They were only a beginning, a jumping-off place. The real purpose of interstellar exploration is finding evidence for ideas—ideas that we’ve called pure philosophy, or maybe even religion. If there is a supercivilization, that is the sort of exploring it does.”

“We shouldn’t have named this sun Omega,” said Ardith in a low voice. “We were naive.”

“Very naive. Even those of us who, three days ago, were so proud of being more perceptive than our shipmates.”

“And now we’re paying for our pride,” added Fred.

“No!” Ardith insisted. “This isn’t Omega, yet all the same we had to come here. We got the Message; we simply haven’t discovered how to answer it.”

“We expected it to be easy,” said Reiko. “Just the way astronomers on Earth once thought all they’d have to do would be to decode binary data sent by superior civilizations and get solutions to Earth’s problems. And the way our own expedition set out thinking the Others would hand us the key to the city, so to speak—or start to negotiate for setting up diplomatic relations.”

“Man’s vision of the stars was childish after all,” Fred muttered.

“We are not children now,” declared Jacob. “Either we follow through, or we betray what we are and what we may yet become.”

Ardith said slowly, “You’ve known from the start that it wouldn’t be as anyone thought. You knew most of the staff wouldn’t want to follow through, wouldn’t dare face anything too far from what was expected. Do you know what more is demanded of us?”

“No,” Jacob admitted. “Only that we can’t give up yet, and that nobody will show us the way forward.”

“And there is a way.” The way forward always exists, she reminded herself. That’s the only reason any species evolves.

“Logically, it’s impossible that we’re all deluded. One or two cases of strange dreams might be mental imbalance. Seven of us, separately convinced—” All of them looked at each other. There was no use in talking about it any longer, and in fact they had never talked much about the dreams; what happened in the dreams was too hard to express. Nevertheless their knowledge of it was shared.

By unspoken agreement they lay down once more to seek sleep. The small ship, for the time being unpowered, sped in its orbit around the alien sun, carrying them toward unknown regions. Ardith closed her eyes and felt herself falling, though she was well accustomed to zero gravity. She was dizzy, perhaps from hunger; they were stretching their rations as far as possible, and fasting, they knew, might intensify their dreams. It was a risk: on Earth, the dreams of fasting seers had not always been as valid as they seemed. Yet now only desperate measures were left ...

She fell into black space. The worlds were tiny and very distant. For the first time her dream verged on nightmare. Somewhere a long way back were Earth and LaLande VI and all the other safe, familiar planets where mankind belonged, where the pattern of things was lucid; but she was cut off from them. She was cut off from everything. She could not find her way to the worlds of the Others. They were there and they were beautiful, but it was an alien, terrible beauty, past all comprehension. And there were perils there, also. She was not equipped to cope with such perils; she wanted only to withdraw ... even to withdraw into nothingness. Though it was fearful, she feared the bright worlds more; and of her longing and her fear, she was not sure which was worst.

Ardith came to herself, cold and trembling. While the dream stayed clear in her mind, she recalled snatches of past ones, too: both the wonders and the terrors. There had been terrors; why had she not recalled them consciously? Why had she sought a universe where man’s works were the games of children; where man’s symbols were abandoned toys, cherished for past value, but no longer of real use? Once you entered such a universe, you could never go back.

And they would have to go back—soon, if they failed, if their life- support ran out before they found the way through the Others’ shield; but anyway, eventually. Wouldn’t they?

No, Ardith saw suddenly, not if what they were seeking was a real step in evolution. Evolution didn’t work like that.

With rising fear, she began to perceive the way forward.

“It’s the only answer,” she told the others, now all awake, clustered around her in the dimly-lit compartment. “We’re not committed. We are still thinking of going back.”

There was silence. Finally Jacob said, “I believe you’re right. We can’t have it both ways. Oh, we may return to Earth someday—we, or others like us—once we’ve found what it lies within us to be. We are still members of our own human race; they are not gods, and they won’t do anything to change us, We’re pioneers, not deserters: we’ll play some role in changes already happening to mankind. We’ll become emissaries, perhaps. But we must not count on going back in any manner we can foresee.”

“Because they won’t accept us on those terms?” asked Fred.

“It’s not a matter of their accepting us. They’ve issued an invitation to our world; it’s up to us to accept them.”

“To trust them,” Ardith said. “Or at least to trust our own dreams.”

No words were required for the rest of the answer. They all saw it: for their trust, for their commitment, there must be proof. There must be proof in their own minds whether or not any outside agency demanded it. They would not penetrate the shield while they held any tie to Earth’s starship in reserve.

The time was not ripe for full-scale contact between cultures; that must come gradually. And the safeguards did exist. Earth would not find what it was not quite ready to find. So the starship could not return and arouse a controversy, as would surely happen if some were aboard to report a discovery not yet truly sought by the majority. It could return only to report the majority’s view that the Omegan system was planetless and the Message a fake; that there was no known superior civilization; that the people who insisted on following dream trails had been lost in a landing craft with less than three days’ life-support remaining...

The time would never be ripe for contact if no one took the first step.

“There’s an old legend,” murmured Ardith, “about burning one’s own ships—”

“Very ancient,” said Jacob. “A sixteenth-century explorer named Cortez set fire to his fleet so that his expedition couldn’t turn back from the New World. It wasn’t the first such incident. It won’t be the last; the principle is valid.”

“And how would we ... manage it here?”

“If I clear the memory of the astrogation computer,” Fred answered, “we can’t find the starship again. If I rip out certain tracking circuits and then alter our course, it can’t find us. The Captain will try until time runs out for our life-support; after that, his natural assumption will be that we no longer exist.”

We’re crazy, Ardith thought, to stake our lives on what’s really only a guess ... on what, underneath, we fear as much as we long for! Yet evolution always does require that a being adapt or die...

“How much of our time—”

“To do it? A couple of minutes. Close your eyes and it’s finished, if that’s what we all want.”

One by one, they nodded.

For an instant Ardith’s mind was brushed by terror; then joy spread through her, crowding out the fear. She saw the stars as if for the first time, the long-ago time that had seemed past recapturing: the time when they’d been symbols of glories to reach for. How many had worlds shielded from the uncommitted? To how many suns, how many galaxies, would mankind someday be led by her refusal to deny the Message? Along how many beckoning, radiant trails?

She shut her eyes; the ship rotated and through the viewport, the light of the star once called Omega shone warm on her face. Almost at once she saw images from the dreams, though she remained conscious. Soon she would be more fully aware of the universe ahead.