Tommy Evans' ship rested on one of the lower roofs of the city, just outside the laboratories level. In a few minutes now it would be lifted and hurled through a warp of space and time that should place it upon the Earth they had seen in the swirling bowl… an Earth that was no more than a probability… an Earth that wouldn't exist for millions of years if it ever existed.
"Take good care of that ship," Tommy told Gary. Gary slapped him on the arm.
"I'll bring it back to you," he said.
"Well be waiting for you," Kingsley rumbled.
"Hell," moaned Herb, "I never get to have any fun. Here you and Caroline are going out there to the Earth and I got to stay behind.”
"Listen," said Gary savagely, "there's no use in risking all our lives.
Caroline's going because she may be the only one who could understand what the old Earth people can tell us, and I'm going because I play a better hand of poker. I beat you all, fair and square.”
"I was a sucker," mourned Herb. "I should have known you'd have an ace in the hole. You always got an ace in the hole.”
Tommy grinned.
"I got a lousy band," he said. "We should have played more than just one band.”
"It was one way of deciding it," said Gary. "We all wanted to go, so we played one hand of poker. We couldn't waste time for more. I won. What more do you want?”
"You always win," Herb complained.
"Just how much chance have you got?" Tommy asked Caroline.
She shrugged.
"It works out on paper," she declared. "When we came here the Engineers had to distort time and space to get us here, but they distorted the two equally. Same amount of distortion for each. But here you have to distort time a whole lot more. Your factors are different. But we have a good chance of getting where we're going?’
"If it's there when you get there…" Herb began, but Kingsley growled at him and he stopped.
Caroline was talking swiftly to Kingsley.
"The Engineer understands the equation for the hyperspheres," she was saying. "Work with him. Try to set up several of them in our own space and see if it isn't possible to set up at least one outside the universe. Pinch it off the time-space warp and shove it out into the inter-space. We may be able to use it later on.”
A blast of sound smote them and the solid masonry beneath their feet shivered to the impact of a bomb. For a single second the flashing blaze of atomic fury made the brilliant sunlight seem pale and dim.
"That one was close," said Tommy.
They were used to bombs now.
Gary craned his neck upward and saw the silvery flash of ships far overhead.
"The Engineers can't hold out much longer," Kingsley rumbled. "If we are going to do anything we have to do it pretty soon.”
"There is the old space warp again," said Herb. He pointed upward and the others sighted out into space beyond his pointing finger.
There it was… the steady wheel of light, the faint spin of space in motion… they had seen back on Pluto.
The doorway to another world.
"I guess," said Caroline, "that means we have to go." Her voice caught on something that sounded like a sob.
She turned to Kingsley. "If we don't come back," she said, "try the hyperspheres anyhow. Try to absorb the energy in them. You won't have to control it long. Just long enough so the other universe explodes. Then we'll be safe.”
She stepped through the air lock and Gary followed her. He turned back and looked at the three of them… great, rumbling Kingsley with his huge head thrust forward, staring through his helmet, with his metal-shod fists opening and closing; dapper, debonair Tommy Evans, the boy who had dreamed of flying to Alpha Centauri and had come to the edge of the universe instead; Herb, the dumpy little photographer who was eating out his heart because he couldn't go. Through eyes suddenly bleared with emotion, Gary waved at them and they waved back. And then he hurried into the ship, slammed down the lever that swung tight the air-lock valves.
In the control room he took off his helmet and dropped into the pilot's seat. He looked at Caroline. "Good to get the helmet off," he said.
She nodded, lifting her own off her head.
His fingers tapped out a firing pattern. He hesitated for a moment, his thumb poised over the firing lever.
"Listen, Caroline," be asked, "how much chance have we got?”
"We'll get there," she said.
"No," he snapped, "don't tell me that. Tell me the truth. Have we any chance at all?”
Her eyes met his and her mouth sobered into a thin, straight line.
"Yes, some," she said. "Not quite fifty-fifty. There are so many factors of error, so many factors of accident. Mathematics can't foresee them, can't take care of them, and mathematics are the only signposts that we have.”
He laughed harshly.
"We're shooting at a target, don't you see?" she said. "A target millions of light-years away, and millions of years away as well, and you have to have a different set of co-ordinates for both the time and distance. The same set won't do for both. It's difficult.”
He looked at her soberly. She said it was difficult. He could only faintly imagine how difficult it might be. Only someone who was a master at the mathematics of both time and space could even faintly understand — someone, say, who had thought for forty lifetimes.
"And even if we do hit the place," he said, "it may not be there.”
Savagely he plunged his thumb against the lever. The rockets thundered and the ship was arcing up. Another pattern and another. They were plunging upward now under the full thrust of rocket power and still the ruined city was all around them, cragged, broken towers shattered by the blasting of atomic energy.
The soft swirl of light that marked the opening of the time-space tunnel lay between and beyond two blasted towers. Gary fired a short, corrective pattern to line the nose of the ship between the towers and then depressed a stud and fired a blast that drove them straight between the towers, up and over the city, straight for the whirl of light.
The ship arrowed swiftly up. The directional crossbars lined squarely upon the hub of spinning light.
"We're almost there," he said, his breath whistling between his teeth.
"We'll know in just a minute.”
The cold wind out of space was blowing on his face again; the short hairs on his neck were trying to rise into a ruff. The old challenge of the unknown. The old glory of crusading.
He snapped a look at Caroline. She was staring out of the vision plate, staring straight ahead, watching the rim of the wheel spin out until only the blackness of the hub remained.
She turned to him. "Oh, Gary!" she cried, and then the ship plunged into the hub and blackness as thick and heavy and as stifling as the ink of utter space flooded into the ship and seemed to dim the very radium lamps that burned within the room. He heard her voice coming out of the blackness that engulfed them. "Gary, I'm afraid!”
Then the black was gone and the ship rode in space again — in a star-sprinkled space that had, curiously, a warm and friendly look after the blackness of the tunnel.
"There it is!" Caroline cried, and Gary expelled his breath in a sigh of relief.
Below them swam a planet, a planet such as they had seen in the spinning bowl back in the city of the Engineers. A planet that was spotted with mighty mountains weathered down to meek and somber hills, a planet with shallow seas and a thinning atmosphere.
"The Earth," said Gary, looking at it.
Yes, the Earth. The birthplace of the human race, now an old and senile planet tottering to its doom, a planet that had outlived its usefulness. A planet that had mothered a great race of people — a race that always strove to reach what was just beyond, always reaching out to the not-as-yet, that met each challenge with a battle cry. A crusading people.
"It's really there," said Caroline. "It's real.”
Gary glanced swiftly at the instruments. They were only a matter of five hundred miles above the surface and as yet there was no indication of atmosphere. Slowly the ship was dropping toward the planet, but still there was no sign of anything but space.
He whistled softly. Even the slightest presence of gases would be registered on the dials and so far the needles hadn't even flickered.
Earth must be old! Her atmosphere was swiftly being stripped from her to leave her bare bones naked to the cold of space. Space, cold and malignant, was creeping in on mankind's cradle.
He struck the first sign of atmosphere at slightly under two hundred miles.
The surface of the planet was lighted by a Sun which must have lost much of its energy, for the light seemed feeble compared to the way Gary remembered it. The Sun, behind them, was shielded from their vision.
Swiftly they dropped, closer and closer to the surface. Eagerly they scanned the land beneath them for some sign of cities, but they saw only one and that, the telescope revealed, was in utter ruins. Drifting sands were closing over its shattered columns and once mighty walls.
"It must have been a great city in its day," said Caroline softly. "I wonder what has happened to the people.”
"Died off," said Gary, "or left for some other planet, maybe for some other sun.”
The telescopic screen mirrored scene after scene of desolation. Vast deserts with shifting dunes and mile after mile of nothing but shimmering sand, without a trace of vegetation. Worn-down hills with boulder-strewn slopes and wind-twisted trees and shrubs making their last stand against the encroachment of a hostile environment.
Gary turned the ship toward the night side of the planet, and it was then they saw the Moon. Vast, filling almost a twelfth of the sky, it loomed over the horizon, a monstrous orange ball in full phase.
"How pretty!" gasped Caroline.
"Pretty and dangerous," said Gary.
It must be approaching Roche's limit, he thought. Falling out of the sky, year after year it had drawn closer to the Earth. When it reached a certain limit, it would be disrupted, torn to bits by the stresses of gravitation hauling and tugging at it. It would shatter into tiny fragments and those fragments would take up independent orbits around old Earth, giving her in miniature the rings of Saturn. But the same forces which would tear the Moon to bits would shake up the Earth, giving rise to volcanic action, world-shattering earthquakes, monstrous tidal waves. Mountains would be leveled, new continents raised. Earth's face would be changed once again, as it probably had been changed many times before. As it had been changed since early Man had known it, for search as he might, Gary could find no single recognizable feature, not a single sea or continent that seemed familiar.
He reflected on the changes that must have come to pass. The Earth must have slowed down. Probably a night now was almost a month long, and a day equally as long. Long scorching days and endless frigid nights. Century after century, with the moon tides braking the Earth's motion, with the addition of mass due to falling meteors, Earth had lost her energy.
Increase of mass and loss of energy had slowed her spin, had shoved her farther and farther away from the Sun, pushing her out and into the frigidness of space. And now she was losing her atmosphere. Her gravity was weakening and the precious gases were slowly being stripped from her. Rock weathering also would have absorbed some of the oxygen.
"Look!" cried Caroline.
Aroused from his daydreaming, Gary saw a city straight ahead, looming on the horizon, a great city a-gleam with shining metal.
"The Engineer said we would find people here," Caroline whispered. "That must be where we'll find them.”
The city was falling into ruin. Much of it, undoubtedly, already had been covered by the creeping desert that crawled toward it from every direction.
Some of the buildings were falling apart, with great gaping holes staring like empty, hopeless eyes. But part of it, at least, was standing, and that part gave a breath-taking hint to the sort of city it had been when it soared in full pride of strength at its very prime.
Smoothly Gary brought the ship down toward the city, down toward a level patch of desert in front of the largest building yet standing. And the building, he saw, was a beauteous thing that almost defied description, a poem in grace and rhythm, seemingly too fragile for this weird and bitter world.
The ship plowed along the sand and stopped. Gary rose from the pilot's seat and reached for his helmet. "We're here," he announced.
"I didn't think we'd make it," Caroline confessed. "We took such an awful chance.”
"But we did," he said gruffly. "And we have a job to do.”
He set his helmet on his head and clamped it down. "I have a hunch we'll need these things," he said.
She put on her helmet and together they went out of the air lock.
Wind keened thinly over the empty deserts and the ruins, kicked up little puffs of sand that raced and danced weird rigadoons across the dunes and past the ship, up to the very doors of the shiny building that confronted them.
A slinking shape slunk across a dune and streaked swiftly for the shelter of a pile of fallen masonry — a little furtive shape that might have been a skulking dog or something else, almost anything at all.
A sense of desolation smote Gary and he felt an alien fear gripping at his soul.
He shivered. This wasn't the way a man should feel on his own home planet.
This wasn't the way a man should feel on coming home from the very edge of everything.
But it wasn't the edge of everything, he reminded himself. It was just the edge of the universe. For the universe wasn't everything. Beyond it, stretching for uncountable, mind-shattering distances, were other universes. The universe was just a tiny unit of the whole, perhaps as tiny a unit of the whole as the Earth was a tiny unit of its universe. A grain of sand upon the beach, he thought — less than a grain of sand upon the beach.
And this might not be Earth, of course. It might be just the shadow of the Earth — a probability that gained strength and substance and a semblance of being because it missed being an actuality by a mere hair's-breadth.
His mind whirled at the thought of it, at the astounding vista of possibilities that the thought brought up, the infinite number of possibilities that existed as shadows, each with a queer shadow existence of its very own, things that just missed being realities. Disappointed ghosts, he thought, wailing their way through the eternity of nonexistence.
Caroline was close beside him. Her voice came to him through the helmet phones, a tiny voice. "Gary, everything is so strange.”
"Yes," he said. "Strange.”
Cautiously they walked forward, toward the gaping door of the great metal building from whose turrets and spires and froth of superstructure the moonbeams splintered in a cold glitter of faery beauty.
Sand crunched and grated underfoot. The wind made shrill, keening noises and they could see the frozen frost crystals in the sand, moisture locked in the grip of deadly cold.
They reached the doorway and peered inside. The interior was dark and Gary unhooked the radium lamp from his belt. The lamp cut a broad beam of light down the mighty, high-arched hallway that led straight from the door toward the center of the building.
Gary caught his breath, seized with a nameless fear, the fear of the dark and the unfamiliar, of the ghostly and the ancient.
"We might as well go in," he said, fighting down the fear.
Their footsteps echoed and re-echoed in the darkness as the metal of their boots rang against the cold paving blocks.
Gary felt the weight of centuries pressing down upon him — the eyes of many nations and of many people watching furtively, jealous to guard old tradition from the invasion of an alien mind. For he and Caroline, he sensed, were aliens here, aliens in time if not in blood. He sensed it in the very architecture of the place, in the atmosphere of the long and silent hall, in the quiet that brooded on this dead or dying planet.
Suddenly they left the hallway and were striding into what seemed a vast chamber. Gary snapped the lamp to full power and explored the place. It was filled with furniture. Solid blocks of seat faced a rostrum, and all about the wall ran ornate benches.
At one time, now long gone, it might have been a council hall, a meeting place of the people to decide great issues. In this room, he told himself, history might have been written, the course of cosmic empire might have been shaped and the fate of stars decided.
But now there was no sign of life, just a brooding silence that seemed to whisper in a tongueless language of days and faces and problems long since wiped out by the march of years.
He looked about and shivered.
"I don't like this place," said Caroline.
A light suddenly flared and blazed as a door opened and thought-fingers reached out to them, thoughts that were kindly and definitely human:
"Do you seek someone here?”