“No. There has to be continuity. They couldn’t have reached a technological level that would allow them to send transgalactic messages at all unless they were able to retain the achievements of earlier generations.”

Krug swung round. “You know something? This planetary nebula, this blue sun — I still don’t believe it could have intelligent beings living there. Any kind of life — no! Listen, blue suns don’t last long, Vargas. It takes millions of years for the surface of a planet just to cool enough to get solid. There isn’t that much time, a blue sun. Any planets it’s got, they’re still molten. You want me to believe signals coming from people who live on a fireball?”

Vargas said quietly, “Those signals come from NGC 7293, that planetary nebula in Aquarius.”

“For sure?”

“For sure. I can show you all the data.”

“Never mind. But how, a fireball?”

“It’s not necessarily a fireball. Maybe some planets cool faster than others. We can’t be sure how long it takes them to cool. We don’t know how far the home world of the message-senders is from that sun. We’ve got models showing the theoretical possibility that a planet can cool fast enough, even with a blue sun, to allow—”

“It’s a fireball, that planet,” said Krug sullenly.

Defensive now, Vargas said, “Perhaps. Perhaps not. Even if it is: must all life-forms live on a solid-surface planet? Can’t you conceive a civilization of high-temperature entities evolving on a world that hasn’t cooled yet? If—”

Krug snorted in disgust. “Sending signals with machines made of molten steel?”

“The signals don’t have to be mechanical in origin. Suppose they can manipulate the molecular structure of—”

“You talk fairy tales to me, doctor. I go to a scientist, I get fairy tales!”

“At the moment fairy tales are the only way of accounting for the data,” Vargas said.

“You know there’s got to be a better way!”

“All I know is that we’re getting signals, and they undoubtedly come from this planetary nebula. I know it isn’t plausible. The universe doesn’t have to seem plausible to us all the time. Its phenomena don’t have to be readily explicable. Transmat wouldn’t be plausible to an eighteenth-century scientist. We see the data as best we can, and we try to account for it, and sometimes we do some wild guessing because the data we’re getting doesn’t seem to make sense, but—”

“The universe doesn’t cheat,” Krug said. “The universe plays fair!”

Vargas smiled. “No doubt it does. But we need more data before we can explain NGC 7293. Meanwhile we make do with fairy tales.”

Krug nodded. He closed his eyes and fondled dials and meters, while within him a monstrous raging impatience sizzled and blazed and bubbled.Hey, you star people! Hey, you, sending those pulses! Who are you? What are you? Where are you? By damn, I want to know!

What are you trying to tell us, you?

Who are you looking for?

What’s it all mean? Suppose I die before I find out!

“You know what I want?” Krug said suddenly. “To go outside, to that radio telescope of yours. And climb up into the big dish. And cup my hands and shout at those bastards with the numbers. What’s the signal now? 2-5-1, 2-3-1, 2-1? It drives me crazy. We ought to answer them right now. Send some numbers: 4-10-2, 4-6-2, 4-2. Just to show them we’re here. Just to let them know.”

“By radio transmission?” Vargas said. “It’ll take 300 years. The tower will be finished soon.”

“Soon, sure. Soon. You ought to see it. Come see, next week. They’re putting the gadgets in it now. We’ll be talking to the bastards soon.”

“Would you like to hear the audio signal coming in, the new one?”

“Sure.”

Vargas touched a switch. From speakers in the laboratory wall came a dry cold hiss, the sound of space, the voice of the dark abyss. It was a sound like a cast-off snakeskin. Overriding that withered sound, seconds later, came sweet upper-frequency tones.Pleep pleep. Pause.Pleep pleep pleep pleep pleep. Pause.Pleep. Pause. Pause.Pleep Pleep. Pause.Pleep pleep pleep. Pause.Pleep. Pause. Pause.Pleep pleep. Pause.Pleep. Silence. And then again,pleep pleep, the new cycle beginning.

“Beautiful,” Krug whispered. “The music of the spheres. Oh, you mysterious bastards! Look, doctor, you come see the tower next week, next — oh, Tuesday. I’ll have Spaulding call you. You’ll be amazed. And listen, anything else new comes up, another change in the signal, I want to hear right away.”

Pleep pleep pleep.

He headed for the transmat.

Pleep.

Krug leaped northward along the meridian, following the line of 90 DEGREES E., looped the North Pole, and emerged beside his tower. He had sped from icy plateau to icy plateau, from the world’s bottom to its top, from late spring to early winter, from day to night. Androids were busy everywhere. The tower seemed to have grown fifty meters since yesterday’s visit. The sky was ablaze with the light of reflector plates. The song of NGC 7293 sang seductively in Krug’s mind.Pleep pleep pleep.

He found Thor Watchman in the control center, jacked in. The alpha, unaware of Krug’s presence, seemed lost in a drugged dream, climbing the precipices of some distant interface. An awed beta offered to cut into the circuit and tell Watchman, via the computer, that Krug had arrived. “No,” Krug said. “He’s busy. Don’t bother him.”Pleep pleep pleep pleep pleep. He stood for a few moments, watching the play of expressions on Watchman’s tranquil face. What was passing through the alpha’s mind now? Freight invoices, transmat manifests, welding cues, weather reports, cost estimates, stress factors, personnel data? Krug felt pride geysering in his soul. Why not? He had plenty to be proud of. He had built the androids, and the androids were building the tower, and soon man’s voice would go forth to the stars—

Pleep pleep pleep. Pleep.

Affectionately, a little surprised at himself, he put his hands to Thor Watchman’s broad shoulders in a quick embrace. Then he went out. He stood in the frigid blackness a short while, surveying the frenzied activity at every level of the tower. On top they were putting new blocks in place with flawless rhythm. Inside, the tiny figures were hauling neutrino-sheathing around, joining lengths of copper cable, installing floors, carrying the heat-cool-power-light system higher and higher. Through the night came a steady pulsation of sound, all the noises of construction blending into a single cosmic rhythm, a deep booming hum with regular soaring climaxes. The two sounds, the inner and the outer one, met in Krug’s mind,boom andpleep, boom andpleep, boom andpleep.

He walked toward the transmats, ignoring the knives of the Arctic wind.

Not bad for a poor man without much education, he told himself. This tower. These androids. Everything. He thought of the Krug of forty-five years ago, the Krug growing up miserable in a town in Illinois with grass in the middle of the streets. He hadn’t dreamed much about sending messages to the stars then. He just wanted to make something out of himself. He wasn’t anything, yet. Some Krug! Ignorant. Skinny. Pimpled. Sometimes on holocasts he heard people saying that mankind had entered a new golden age, with population down, social and racial tensions forgotten, a horde of servomechanisms to do all the dirty work. Yes. Yes. Fine. But even in a golden age somebody has to be on the bottom. Krug was. Father dead when he was five. Mother hooked on floaters, sensory scramblers, any kind of dream-pills. They got a little money, not much, from a welfare foundation. Robots? Robots were for other people. Half the time the data terminal, even, was shut off for unpaid bills. He never went through a transmat until he was nineteen. Never even left Illinois. He remembered himself: sullen, withdrawn, squint-eyed, sometimes going a week or two without speaking to anyone. He didn’t read. He didn’t play games. He dreamed a lot, though. He slid through school in a haze of rage, learning nothing. Slowly coming out of it when he was fifteen, propelled by that same rage, turning it suddenly outward instead of letting it fester within:I show you what I can do, I get even with you all! Self-programming his education. Servotechnology. Chemistry. He didn’t learn basic science; he learned ways of putting things together. Sleep? Who needed sleep? Study. Study. Sweat. Build. A remarkable intuitive grasp of the structure of things, they said was what he had. He found a backer in Chicago. The age of private capitalism was supposed to be dead; so was the age of free-lance invention. He built a better robot, anyway. Krug smiled, remembering: the transmat hop to New York, the conferences, the lawyers. And money in the bank. The new Thomas Edison. He was nineteen. He stocked his laboratory with equipment and looked for grander projects. At twenty-two, he started to create the androids. Took awhile. Somewhere in those years, the probes began coming back from the near stars, empty. No advanced life-forms out there. He was secure enough now to divert some attention from business, to allow himself the luxury of wondering about man’s place in the cosmos. He pondered. He quarreled with the popular theories of the uniqueness of man. Went on toiling, though, diddling with the nucleic acid, blending, hovering over centrifuges, straining his eyes, dipping his hands deep into tubs of slime, hooking together the protein chains, getting measurably closer to success. How can man be alone in the universe if one man himself can make life? Look how easy it is! I’m doing it: am I God? The vats seethed. Purple, green, gold, red, blue. And eventually life came forth. Androids shakily rising from the foaming chemicals. Fame. Money. Power. A wife; a son; a corporate empire. Properties on three worlds, five moons. Women, all he wanted. He had grown up to live his own adolescent fantasies. Krug smiled. The young skinny pimpled Krug was still here within this stocky man, angry, defiant, burning. You showed them, eh? You showed them! And now you’ll reach the people in the stars.Pleep pleep pleep. Boom. The voice of Krug spanning the light-years. “Hello? Hello? Hello, you! This is Simeon Krug!” In retrospect he saw his whole life as a single shaped process, trending without detour or interruption toward this one goal. If he had not churned with intense, unfocused ambitions, there would have been no androids. Without his androids, there would not have been sufficient skilled labor to build the tower. Without his tower—