The ship was small and dark and unobtrusive, speeding across the Solar System. It had a worn battered look, its plates roughened by strange radiation, dented by tiny meteors, tarnished by alien atmospheres.
It had been far, this ship. In its time it had voyaged to the farthest shores of infinity, carrying its little crew of four on an odyssey unmatched in human annals. It had borne them to perils far around the universe — and back again.
But not even the man who sat at its controls could dream that now, here inside the familiar System, it was bearing him toward the most strange and soul-shaking experience of all. .
Curt Newton was oppressed, not by premonitions but by a self-accusing regret. The deep worry that he felt showed in the tautness of his face, in the set of his lean body. His red head was bent forward, his gray eyes anxiously searching the sunbeaten reaches of space ahead.
The little ship was inside the orbit of Mercury. The whole sky ahead was dominated by the monster bulk of the Sun. It glared like a universe of flame, crowned by the awful radiance of its corona, reaching out blind mighty tentacles of fire.
Newton scanned the region near the great orb’s limb. The impatience that had spurred him across half the System grew to an intolerable tension.
He said almost angrily, “Why couldn’t Carlin let well enough alone? Why did he have to go to Vulcan?”
“For the same reason”, answered a precise metallic voice from behind his shoulder, “that you went out to Andromeda. He is driven by the need to learn.”
“He wouldn’t have gone if I hadn’t told him all about Vulcan. It’s my fault, Simon.”
Curt Newton looked at his companion. He saw nothing strange in the small square case hovering on its traction beams — the incredibly intricate serum-case that housed the living brain of him who had been Simon Wright, a man. That artificial voice had taught him his first words, the lens-like artificial eyes that watched him now had watched his first stumbling attempts to walk, the microphonic ears had heard his infant wails.
“Simon — do you think Carlin is dead?”
“Speculation is quite useless, Curtis. We can only try to find him.”
“We’ve got to find him”, Newton said, with somber determination. “He helped us when we needed help. And he was our friend.”
Friend. He had had so few close human friends, this man whom the System called Captain Future. Always he had stood in the shadow of a loneliness that was the inescapable heritage of his strange childhood.
Orphaned almost at birth he had grown to manhood on the lonely Moon, knowing no living creature but the three unhuman Futuremen. They had been his playmates, his teachers, his inseparable companions. Inevitably by that upbringing he was forever set apart from his own kind.
Few people had ever penetrated that barrier of reserve. Philip Carlin had been one of them. And now Carlin was gone into mystery.
“If I had been here”, Newton brooded, “I’d never have let him go.”
A BRILLIANT scientist Carlin had set out to study the mysteries of that strange world inside Vulcan which the Futuremen had discovered. He had hired a work-ship with heavy anti-heat equipment to take him to Vulcan, arranging for it to come back there for him in six months.
But when the ship returned it had found no trace of Carlin in the ruined city that had been his base of operations. It had, after a futile search, come back with the news of his disappearance.
All this had happened before the return of the Futuremen from their epoch-making voyage to Andromeda. And now Curt Newton was driving sunward, toward Vulcan, to solve the mystery of Carlin’s fate.
Abruptly, from beyond the bulkhead door of the bridge-room, two voices, one deep and booming, the other lighter and touched with an odd sibilance, were raised in an outburst of argument.
Newton turned sharply. “Stop that wrangling! You’d better get those anti-heaters going or we’ll all fry.”
The door slid open and the remaining members of the unique quartet came in. One of them, at first glance, appeared wholly human — with a lithe lean figure and finely-cut features. And yet in his pointed white face and bright ironic eyes there lurked a disturbing strangeness.
A man but no kin to the sons of Adam. An android, the perfect creation of scientific craft and wisdom — humanity carried to its highest power, and yet not human. He carried his difference with an air but Curt Newton was aware that Otho was burdened with a loneliness far more keen than any he could know himself.
The android said quietly, “Take it easy, Curt. The unit’s already functioning.”
He glanced through the window at the glaring vista of space and shivered. “I get edgy myself, playing around the Sun this close.”
Newton nodded. Otho was right. It was one thing to come and go between the planets, even between the stars. It was a wholly different thing to dare approach the Sun.
The orbit of Mercury was a boundary, a limit. Any ship that went inside it was challenging the awful power of the great solar orb. Only ships equipped with the anti-heat apparatus dared enter that zone of terrible force — and then only at great peril.
Only the fourth of the Futuremen seemed unworried. He crossed to the window, his towering metal bulk looming over them all. The same scientific genius that had created the android had shaped also this manlike metal giant, endowing him with intelligence equal to the human and with a strength far beyond anything human.
Grag’s photoelectric eyes gazed steadily from his strange metal face, into the wild shaking glare. “I don’t know what you’re jumpy about”, he said. “The Sun doesn’t bother me a bit.” He flexed his great gleaming arms. “It feels good.”
“Stop showing off”, said Otho sourly.
“You’ll burn out your circuits and we’ve better things to do than trying to cram your carcass out through the disposal lock.”
The android turned to Captain Future. “You haven’t raised Vulcan yet?”
Newton shook his head. “Not yet.”
Presently a faint aura of hazy force surrounded the little ship as it sped on — the anti-heater unit building up full power.
The terrible heat of the Sun could reach through space only as radiant vibrations. The aura generated by the anti— heaters acted as a shield to refract and deflect most of that radiant heat.
Newton touched a button. Still another filter-screen, this one the heaviest of all, slid across the window. Yet even through all the screens the Sun poured dazzling radiance.
The temperature inside the ship was steadily rising. The anti-heaters could not deflect all the Sun’s radiant heat. Only a fraction got through but that was enough to make the bridge-room an oven.
An awed silence came upon the Futuremen as they looked at the mighty star that filled almost all the firmament ahead. They had been this close to the Sun before but no previous experience could lessen the impact of it.
You never saw the Sun until you got this close, Newton thought. Ordinary planet-dwellers thought of it as a beneficent golden thing in the sky, giving them heat and light and life. But here you saw the Sun as it really was, a throbbing seething core of cosmic force, utterly indifferent to the bits of ash that were its planets and to the motes that lived upon those ashes.
They could, at this distance, clearly see gigantic cyclones of flame raging across the surface of the mighty orb. Into those vortices of fire all Earth could have been dropped and from around them exploded burning geysers that could have shrivelled worlds.
Sweat was running down Curt Newton’s face now and he gasped a little for each breath. “Temperature, Otho?” he asked without turning his head.
“Only fifty degrees under the safety limit and the anti-heaters running full load”, said the android. “If we’ve miscalculated course —”
“We haven’t”, said Captain Future. “There’s Vulcan ahead.”
The planetoid, the strange lonely little solar satellite, had come into view as a dark dot closely pendant to the skyfilling Sun.
Newton drove the Comet forward unrelentingly now. Every moment this close to the Sun there was peril. Let the anti-heaters stop one minute and metal would soften and fuse, flesh would blacken and die.
Otho suddenly raised his hand to point, crying out, “Look! Sun-children!”
They had heard of the legendary “Sun— children” from the Vulcanian natives, had once glimpsed one far off. But these two were nearer. Newton, straining his eyes against the solar glare, could barely see the things — two whirling little wisps of flame, moving fast through the blinding radiance of the corona.
Then the two will-o-wisps of fire had disappeared in the vast glare. The eye searched for them in vain.
“I still think”, Simon was saying, “that they’re just wisps of flaming hydrogen that are flung off the Sun and then fall back again.”
“But the Vulcanians told of them coming down into Vulcan”, Otho objected. “How could bits of flaming gas do that Curt NEWTON hardly listened. He was already whipping the ship in around Vulcan in a tight spiral few spacemen would have risked. Its brake rockets thundering, it scudded low around the surface of the little world.
The whole surface was semi-molten rock. The heat of the planetoid’s stupendous neighbor kept its outer skin half-melted. Lava sweltered in great pools, infernal lagoons framed by smoking rock hills. Fire burst up from the rocks, as though called forth by the nearby Sun.
Grag first saw what they were looking for — a gaping round pit in the sunward side of the planetoid. Presently Captain Future had the Comet hovering on keel-jets above the yawning shaft. He eased on the power-pedal and the little ship dropped straight down into the pit.
This shaft was the one way inside the hollow solar satellite. At the planetoid’s birth gases trapped within it had caused it to form as a hollow shell. Those gases, finally bursting out as pressure increased, had torn open this way to the outer surface.
The ship sank steadily down the shaft. Light was around them for this side of Vulcan was toward the Sun now and a great beam entered.
Then, finally, the shaft debouched into a vast space vaguely lighted by that beam — the interior of the hollow world.
“Whew, I’m glad to be in here out of that solar radiance”, breathed Otho. “Now where?”
Newton asked, “The ruins near Yellow Lake, wasn’t it?”
“Yes”, answered the Brain’s metallic voice. “It was where the ship left Carlin and where it was to pick him up.”
The Futuremen had been here inside Vulcan once before. Yet they felt again the wonder of this strangest world in the System as the Comet flew low over its inner surface.
Beneath their flying ship stretched a weird landscape of fern jungles. It extended into a shrouding haze ahead, the horizon fading away in an upward curve. Over their heads now was the hazy “sky” of the planetoid’s central hollow, cut across by the tremendous, glittering sword of the giant beam of sunlight that gave light to this world.
As their ship slanted down over the fern jungle toward their destination a feeling of gray futility came upon Curt Newton. Months had passed since Philip Carlin had disappeared here. Could the scientist have survived alone so long in his wild world?
A city wrecked by time lay beneath them, almost swallowed by the giant ferns. Only scattered crumbling stones of massive dimensions had survived the ravages of unthinkable ages. It was like the flotsam of a lost ship, floating up out of the past.
The Comet came to rest upon cracked paving surrounded by towering shattered monoliths. The Futuremen went out into the steamy air.
“It was here that Carlin was to meet the ship when it came”, said Captain Future. “And he wasn’t here.” He spoke in a lowered voice. The brooding silence of this memorial of lost greatness laid a cold spell upon them all.
These broken mighty stones were all that remained of a city of the Old Empire, that mighty galactic civilization mankind had attained to long ago. On worlds of every star its cities and monuments had risen, then had passed — had passed so completely that men had had no memory of it until the Futuremen probed back into cosmic history.
Long ago the mighty ships of the star— conquering Empire had come to colonize even hollow Vulcan. Men and women with the powers of a brilliant science and with proud legends of victorious cosmic conquest had lived and loved and died here. But the Empire had fallen and its cities had died and the descendants of its people here were barbarians now.
“The first thing”, Newton was saying, “is to get in touch with the Vulcanians and find out what they know about Carlin.”
Grag stood, his metal head swivelling as he stared around the ruins. “No sign of them here. But those primitives always are shy.”
“We’ll look around first for some trace of Carlin here then”, Newton decided.
The quartet started through the ruins — the man and the mighty clanking robot, the lithe android and the gliding Brain.
Newton felt more strongly the oppressive somberness of this place of vanished glory, as he looked up at the inscriptions in the old language that were carved deep into the great stones. He could read that ancient writing and as he read those proud legends of triumphs long sunken into oblivion he felt the crushing sadness of that greatest of galactic tragedies, the fall of the Old Empire.
Simon’s sharp, metallic voice roused him from his preoccupation. “Curtis! Look here!”
Captain Future instantly strode to where the Brain hovered beside one of the towering monoliths.
“Did you find some trace, Simon?”
“Look at that inscription! It’s in the old language — but it’s newly carved!”
Newton’s eyes widened. It was true. On that monolith, a few feet above the ground, was a chiseled legend in the language that had not been used for ages. Yet the characters were raw, new, only faintly weathered.
“It was carved less than a year ago!” he said. His pulses suddenly hammered. “Simon, Carlin knew the old language! He had me teach it to him, remember!”
“You mean — Carlin carved this one?” Otho exclaimed.
“Read it!”cried Grag.
Curt Newton read aloud, “To the Futuremen, if they ever come — I have discovered an incredible secret, the strangest form of life ever dreamed. The implications of that secret are so tremendous that I am going to investigate them first hand. If I do not return be warned that the old citadel beyond the Belt holds the key of a staggering power.”