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                         Transcriber's Note:

    This etext was produced from If Worlds of Science Fiction September
    1952. Extensive research did not uncover any evidence that the U.S.
    copyright on this publication was renewed.


                            [Illustration]


     _They wanted to go home--back to the planet they'd known.
      But even the stars had changed. Did the fate of all creation
      hinge upon an--_


                                  AN

                                EMPTY

                                BOTTLE


                             By Mari Wolf

       *       *       *       *       *




Hugh McCann took the last of the photographic plates out of the
developer and laid them on the table beside the others. Then he picked
up the old star charts--Volume 1, Number 1--maps of space from various
planetary systems within a hundred light years of Sol. He looked
around the observation room at the others.

"We might as well start checking."

The men and women around the table nodded. None of them said anything.
Even the muffled conversation from the corridor beyond the observation
room ceased as the people stopped to listen.

McCann set the charts down and opened them at the first sheet--the
composite map of the stars as seen from Earth. "Don't be too
disappointed if we're wrong," he said.

Amos Carhill's fists clenched. He leaned across the table. "You still
don't believe we're near Sol, do you? You're getting senile, Hugh! You
know the mathematics of our position as well as anybody."

"I know the math," Hugh said quietly. "But remember, a lot of our
basics have already proved themselves false this trip. We can't be
sure of anything. Besides, I think I'd remember this planet we're on
if we'd ever been here before. We visited every planetary system
within a hundred light years of Sol the first year."

Carhill laughed. "What's there to remember about this hunk of rock?
Tiny, airless, mountainless--the most monotonous piece of matter we've
landed on in years."

Hugh shrugged and turned to the next chart. The others clustered
around him, checking, comparing the chart with the photographic plates
of their position, finding nothing familiar in the star pattern.

"I still think we would have remembered this planet," Hugh said. "Just
because it _is_ so monotonous. After all, what have we been looking
for, all these years? Life. Other worlds with living forms, other
types of evolution, types adapted to different environments. This
particular planet is less capable of supporting life than our own
Moon."

Martha Carhill looked up from the charts. Her face was as tense and
strained as her husband's, and the lines about her mouth deeply
etched. "We've got to be near Earth. We've just got to. We've got to
find people again." Her voice broke. "We've been looking for so
long--"

Hugh McCann sighed. The worry that had been growing in him ever since
they first left the rim of the galaxy and turned homeward deepened
into a nagging fear. He didn't know why he was afraid. He too hoped
that they were near Earth. He almost believed that they would soon be
home. But the others, their reactions--He shook his head.

They no longer merely hoped. With them, especially with the older,
ones, it was faith, a blind, unreasoning, fanatic faith that their
journey was almost over and they would be on Earth again and pick up
the lives they had left behind fifty-three years before.

"Look," Amos Carhill said. "Here are our reference points. Here's
Andromeda Galaxy, and the dark nebula, and the arch of our own Milky
Way." He pointed to the places he had named on the plates. "Now we can
check some of these high magnitude reference stars with the charts."

Hugh let him take the charts and go through them, checking, rejecting.
Carhill was probably right. He'd find Sol soon enough.

It had been too long for one shipful of people to follow a quest,
especially a hopeless one. For fifty-three years they had scouted the
galaxy, looking for other worlds with life forms. A check on diverging
evolutions, they had called it--uncounted thousands of suns without
planets, bypassed. Thousands of planetary systems, explored, or merely
looked at and rejected. Heavy, cold worlds with methane atmospheres
and lifeless rocks without atmospheres and even earth-sized,
earth-type planets, with oceans and oxygen and warmth. But no life. No
life anywhere.

That was one of the basics they had lost, years ago--their belief that
life would arise on any planet capable of supporting it.

"We could take a spectrographic analysis of some of those high
magnitude stars," Carhill said. Then abruptly he straightened, eyes
alight, his hand on the last chart. "We don't need it after all.
Look! There's Sirius, and here it is on the plates. That means Alpha
Centauri must be--"

He paused. He frowned and ran his hand over the plate to where the
first magnitude star was photographed. "It must be. Alpha Centauri. It
has to be!"

"Except that it's over five degrees out of position." Hugh looked at
the plate, and then at the chart, and then back at the plate again.
And then he knew what it was that he had feared subconsciously all
along.

"You're right, Amos," he said slowly. "There's Alpha Centauri--about
twenty light years away. And there's Sirius, and Arcturus and
Betelgeuse and all the others." He pointed them out, one by one, in
their unfamiliar locations on the plates. "But they're all out of
position, in reference to each other."

       *       *       *       *       *

He stopped. The others stared back at him, not saying anything. Little
by little the faith began to drain out of their eyes.

"What does it mean?" Martha Carhill's voice was only a whisper.

"It means that we discarded one basic too many," Hugh McCann said.
"Relativity. The theory that our subjective time, here on the ship,
would differ from objective time outside."

"No," Amos Carhill said slowly. "No, it's a mistake. That's all. We
haven't gone into the future. We can't have. It isn't possible that
more time has elapsed outside the ship than--"

"Why not?" Hugh said softly. "Why not millions of years? We've
exceeded the speed of light, many times."

"Which disproves that space-time theory in itself!" Carhill shouted.

"Does it?" Hugh said. "Or does it just mean we never really understood
space-time at all?" He didn't wait for them to answer. He pointed at
the small, far from brilliant, star that lay beyond Alpha Centauri on
the plates. "That's probably Sol. If it is, we can find out the truth
soon enough."

He looked at their faces and wondered what their reactions would be,
if the truth was what he feared.

       *       *       *       *       *

The ship throbbed softly, pulsating in the typical vibrations of low
speed drive. In the forward viewscreens the star grew larger. The
people didn't look at it very often. They moved about the corridors of
the ship, much as they usually moved, but quietly. They seemed to be
trying to ignore the star.

"You can't be sure, Hugh." Nora McCann laid her hand on her husband's
arm.

"No, of course I can't be sure."

The door from their quarters into the corridor was open. Several more
people came in--young people who had been born on the ship. They were
talking and laughing.

"Would it be so hard on the young ones, Hugh? They've never seen the
Earth. They're used to finding nothing but lifeless worlds
everywhere."

One of the young boys in the hall looked up at the corridor viewscreen
and pointed at the star and then shrugged. The others turned away, not
saying anything, and after a minute they left and the boy followed
them.

"There's your answer," Hugh McCann said dully. "Earth's a symbol to
them. It's home. It's the place where there are millions more like us.
Sometimes I think it's the only thing that has kept us sane all these
years--the knowledge that there is a world full of people, somewhere,
that we're not alone."

Her hand found his and he gripped it, almost absently, and then he
looked up at their own small viewscreen. The star was much bigger now.
It was already a definite circle of yellow light.

A yellow G-type sun, like a thousand others they had approached and
orbited around and left behind them. A yellow sun that could have been
anywhere in the galaxy.

"Hugh," she said after a moment, "do you really believe that thousands
of years have gone by, outside?"

"I don't know what to believe. I only know what the plates show."

"That may not even be Sol, up ahead," she said doubtfully. "We may be
in some other part of space altogether, and that's why the charts are
different."

"Perhaps. But either way we're lost. Lost in space or in time or in
both. What does it matter?"

"If we're just lost in space it's not so--so irrevocable. We could
still find our way back to Earth, maybe."

He didn't answer. He looked up at the screen and the circle of light
and his lips tightened. Whatever the truth was, they didn't have long
to wait. They'd be within gravitational range in less than an hour.

He wondered why he was reacting so differently from the others. He was
just as afraid as they were. He knew that. But he wasn't fighting the
thought that perhaps they had really traveled out of their own time.
He wondered what it was that made him different from the other old
ones, the ones like Carhill who refused even to face the possibility,
who insisted on clinging to their illusions in the face of the
photographic evidence.

       *       *       *       *       *

He didn't think that he was a pessimist. And yet, after only three
years of their trip, after only fifty Earthlike but lifeless worlds,
he had been the first to consider the possibility that life was unique
to Earth and that their old theories concerning its spontaneous
emergence from a favorable environment might be wrong.

Only Nora had agreed with him then. Only Nora could face this
possibility with him now. The two of them were very much alike in
their outlooks. They were both pragmatists.

But this time there would be no long years during which the others
could slowly shift their opinions, slowly relinquish their old beliefs
and turn to new ones. The yellow sun was too large and urgent in the
screen.

"Hugh!"

He turned to the door and saw Amos Carhill standing there, bracing
himself against the corridor wall. There was no color at all in
Carhill's face.

"Come on up to the control room with me, Hugh. We're going to start
decelerating any minute now."

Hugh frowned. He would prefer to stay and watch their approach on the
screen, with Nora at his side. He had no duties in the control room.
He was too old to have any part in the actual handling of the ship.
Amos was old, too. But they would be there, all the old ones, looking
through the high powered screens for the first clear glimpse of the
third planet from the sun.

"All right, Amos." Hugh got up and started for the door.

"I'll wait here for you, Hugh," Nora said.

He smiled at her and then followed Carhill out into the crowded
corridor. No one spoke to them. Most of the people they passed were
neither talking, nor paying any attention to anything except the
corridor screens, which they could no longer ignore. The few who were
talking spoke about Earth and how wonderful it would be to get home
again.

"You're wrong, Hugh," Amos said suddenly.

"I hope I am."

The crowd thinned out as they passed into the forward bulkheads. The
only men they saw now were the few young ones on duty. Except for
their set, anxious faces they might have been handling any routine
landing in any routine system.

The ship quivered for just a second as it shifted over into
deceleration. There was an instant of vertigo and then it was gone and
the ship's gravity felt as normal as ever. Hugh didn't even break
stride at the shift.

He followed Carhill to the control room doorway and pushed his way in,
taking a place among the others who already clustered about the great
forward screen. The pilot ignored them and worked his controls. The
screen cleared as the ship's deceleration increased. The pilot didn't
look at it. He was a young man. He had never seen the Earth.

"Look!" Amos Carhill cried triumphantly.

The screen focused. The selector swung away from the yellow sun and
swept its orbits. The dots that were planets came into focus and out
again. Hugh McCann didn't even need to count them, nor to calculate
their distance from the sun. He knew the system too well to have any
trouble recognizing it.

The sun was Sol. The third planet was the double dot of Earth and
moon. He realized suddenly that he had more than half expected to see
an empty orbit.

"It's the Earth all right," Carhill said. "We're home!"

They were all staring at the double dot, where the selector focused
sharply now. Hugh McCann alone looked past it, at the background of
stars that were strewn in totally unfamiliar patterns across the sky.
He sighed.

"Look beyond the system," he said.

They looked. For a long time they stared, none of them speaking, and
then they turned to Hugh, many of them accusingly, as if he himself
had rearranged the stars.

"How long have we been gone?" Carhill's voice broke.

Hugh shook his head. The star patterns were too unfamiliar for even a
guess. There was no way of knowing, yet, how long their fifty-three
years had really been.

       *       *       *       *       *

Carhill shook his head, slowly. He turned back to the screen and
stared at the still featureless dot that was the Earth. "We can't be
the only ones left," he said.

No one answered him. They were still stunned. They couldn't even
accept, yet, the strange constellations on the screen.

End of the voyage. Fifty-three years of searching for worlds with
life. And now Earth, under an unfamiliar sky, and quite possibly no
life at all, anywhere, except on the ship.

"We might as well land," McCann said.

The ship curved away from the night side of the Earth and crossed
again into the day. They were near enough so that the planetary
features stood out sharply now, even through the dense clouds that
rose off the oceans. But although the continental land masses and the
islands were clearly defined, they were as unrecognizable as the star
constellations had been.

"That must be North America," Amos Carhill said dully. "It's smaller
than the continent on the night side...."

"It might be anywhere," Hugh McCann said. "We can't tell. The oceans
look bigger too. There's less land surface."

He stared down at the topography thousands of miles below them.
Mountains rose jaggedly. There were great plains, and crevasses, and a
rocky, lifeless look everywhere. No soil. No erosion, except from the
wind and the rains.

"There's no chlorophyll in the spectrum," Haines said. "It seems to
rule out even plant life."

"I don't understand." Martha Carhill turned away from the screen.
"Everything's so different. But the moon looked just exactly like it
always did."

"That's because it has no atmosphere," Hugh said. "So there's no
erosion. And no oceans to sweep in over the land. But I imagine that
if we explored it we'd find changes. New craters. Maybe even new
mountains by now."

"How long has it been?" Carhill whispered. "And even if it's been
millions of years, what happened? Why aren't there any plants? Won't
we find anything?"

"Maybe there was an atomic war," the pilot said.

"Maybe." Carhill had thought of that too. Probably all of them had.
"Or maybe the sun novaed."

No one answered him. The concept of a nova and then of its dying down,
until now the sun was just as it had been when they left, was too
much.

"The sun looks hotter," Carhill added.

The ship dropped lower, its preliminary circle of the planet
completed. It settled in for a landing, just as it had done thousands
of times before. And the world below could have been any of a thousand
others.

They dropped quickly, braking through the atmosphere, riding it down.
The topography came up to meet them and the general features blurred,
leaving details standing out sharply, increasing in sharpness as if
the valleys and mountains below were tiny microscopic crystals under a
rapidly increasing magnification.

The pilot picked their landing place without difficulty. It was a
typical choice, a spot on the broad shelving plain at the edge of the
ocean. The type of base from which all tests on a planet could be run
quickly, and a report written up, and the files of another world
closed and tagged with a number and entered in one of the great
storage encyclopedias.

Even to Hugh there was an air of unreality about the landing, as if
this planet wasn't really Earth at all, despite its orbit around the
sun, despite its familiar moon. It looked too much like too many
others.

The actual landing was over quickly. The ship quivered, jarred
slightly, and then was still, resting on the gravelled plain that had
obviously once been part of the ocean bed. The ocean itself lay only a
few hundred yards away.

Hugh McCann looked out through the viewscreen, turned to direct vision
now. He stared at the waves swelling against the shore and his sense
of unreality deepened. Even though this was what he had more than half
expected, he couldn't quite accept it, yet.

"We might as well go out and look around," he said.

"Air pressure, Earth-norm." Haines began checking off the control
panel by rote. "Composition: oxygen, nitrogen, water vapor--"

"There's certainly nothing out there that could hurt us," Martha
Carhill snapped. "What could there be?"

"We might check for radioactivity," Hugh said quietly.

She turned and stared at him. Her mouth opened and then snapped shut
again.

"No," Haines said. "There's no radioactivity either. Everything's
clear. We won't need space suits."

He pressed the button that opened the inner locks.

       *       *       *       *       *

Carhill glanced over at him and then switched on the communicator, and
the noises from the rest of the ship flooded into the control room.
Everywhere people were milling about. Snatches of talk drifted in,
caught up in the background as various duty officers, reported
clearance on the landing. Most of the background voices were young,
talking too loudly and with too much forced cheerfulness about what
lay outside the ship.

Hugh sighed, as aware of all the people as if he were out in the
corridors with them. It was the space-born ones who were doing most of
the talking. The children, the young people, the people no longer
young but still born since the voyage started, still looking upon
Earth more as a wonderful legend than as their own place of origin.

The old ones, those who had left the Earth in their own youth, had the
least of all to say. They knew what was missing outside. The younger
ones couldn't really know. Even the best of the books and the pictures
and the three dimensional movies can give only a superficial idea of
what a living world is like.

"Hugh." Carhill clutched his arm.

"Yes, Amos."

"There must be people, somewhere. There have to be. Our race can't be
dead."

Hugh McCann looked past him, out at the sky and the clouds of water
vapor that swirled up to obscure the sun. The stars, of course, were
completely hidden in the daylight.

"If there are any others, Amos, we can be pretty certain they're not
on Earth."

"They may have left. They may have gone somewhere else."

"No!" Martha Carhill's face twisted and then went rigid. "There's no
one anywhere. There can't be. It's been too long. You saw the stars,
Amos--the stars--all wrong, every one of them!"

Her hands came up to her face and she started to cry. Amos crossed
over to her and put his arms around her.

Hugh McCann watched them for a moment and then he turned and left them
and went out through the locks after the young people. He didn't know
what to think. He wished that they had never turned back to Earth at
all, that they had kept going, circling around the rim of the galaxy
forever.

He went through the outer lock and then down the ramp to the ground.

He stood on the Earth again, for the first time since his early youth.
And it was not the same. There was bare rock under his feet and bare
rock all around him, gravel and boulders and even fine grained sand.
But no dust. No dirt. No trace of anything organic or even ever
touched by anything organic.

He had walked too many worlds like this. Too many bare gray worlds
with bare gray oceans and clouds of vapor swirling up into the warm
air. Too many worlds where there was wind and sound and surf; where
there should have been life, but wasn't.

This was just another of those worlds. This wasn't Earth. This was
just a lifeless memory of the Earth he had known and loved. For
fifty-three years they had clung to the thought of home, of people
waiting for them, welcoming them back someday. Fifty-three years, and
for how many of those ship-years had Earth lain lifeless like this?

He looked up at the sky and at all the stars that he couldn't see and
he cursed them all and cursed time itself and then, bitterly, his own
fatuous stupidity.

The people came out of the ship and walked about on the graveled
plain, alone or in small groups. They had stopped talking. They seemed
too numbed by what they had found to even think, for a while.

Shock, Hugh McCann thought grimly. First hysteria and tears and loud
unbelief, and now shock. Anything could come next.

       *       *       *       *       *

He stood with the warm wind blowing in his face and watched the
people. In the bitter mood that gripped him he was amused by their
reactions. Some of them walked around aimlessly, but most, those who
were active in the various departments, soon started about the routine
business of running tests on planetary conditions. They seemed to
work without thinking, by force of habit, their faces dazed and
uncaring.

Conditioning, Hugh thought. Starting their reports. The reports that
they know perfectly well no one will ever read.

He wandered over to where several of the young men were sending up an
atmosphere balloon and jotting down the atmospheric constituents as
recorded by the instruments.

"How's it going?" he said.

"Earth-norm. Naturally--" The young man flushed.

"Temperature's up though. Ninety-three. And a seventy-seven percent
humidity."

He left them and walked down across the rocks to the ocean's edge. Two
young girls were down there before him, sampling the water, running
both chemical and biological probing tests.

"Hello, Mr. McCann," the taller girl said dully. "Want our report?"

"Found anything?" He knew already that there was nothing to find. If
there were life the instruments would have recorded its presence.

"No. Water temperature eighty-six. Sodium chloride four-fifths Earth
normal." She looked up, surprised. "Why so low?"

"More water in the ocean, maybe. Or maybe we've had a nova since we
were here last."

It was getting late, almost sunset. Soon it would be time for the
photographic star-charts to be made. Hugh brought himself up short and
smiled bitterly. He too was in the grip of habit. Still, why not?
Perhaps they could estimate, somehow, how many millions of years had
passed.

Why? What good would it do them to find out?

After a while the sun set and a little later the full moon rose, hazy
and indistinct behind the clouds of water vapor. Hugh stared at it,
watched it rise higher until it cleared the horizon, a great bloated
bulk. Then he sighed and shook his head to clear it and started to
work. The clouds were thick. He had to move the screening adjustment
almost to its last notch before the vapor patterns blocked out and the
stars were bright and unwavering and ready to be photographed. He
inserted the first plate and snapped the picture of the stars whose
names he knew but whose patterns were wrong, some subtly, some
blatantly.

There was something he was overlooking. Some other factor, not taken
into account. He developed the first plates and compared them with the
star charts of Earth as it had been before they left it, and he shook
his head. Whatever the factor was, it eluded him. He went back to
work.

"Oh, here you are, Hugh."

He jumped at the sound of Carhill's voice. He had been working almost
completely by habit, slowly swinging the telescope across the sky and
snapping the plates. And trying to think.

"Why waste time on that?" Carhill added bitterly. "Who's ever going to
see our records now?"

Behind Carhill, several of the other old ones nodded. Hugh was
surprised that they had managed to come back to the ship without his
hearing them. But of course they had come back in at sundown, as
usual on a routine check, and now they were gathering to compile their
reports. Hugh looked from face to face, wondering if he too was as
numb and dazed and haggard appearing as they were. He probably was.

"What do you suggest, Amos?" he said.

"I say there's no use going on," Carhill said flatly. "You've all run
your tests. And what have you found? No fossils. Not even a
single-celled life form in the ocean. No way even to tell how many
millions of years it's been."

"Maybe it hasn't been so long," Haines said. "Maybe something happened
here fairly recently, and the people all went to some other system--to
one of the Centauri planets, maybe."

Amos Carhill laughed bitterly. "You can say that in the face of the
evidence? We _know_ that millions of years have passed. Nothing's the
same. Even the tides are three times what they were. It's obvious what
happened. The sun novaed. Novaed and cooled. Do you really believe
that our race has lasted that long, on some nearby system?"

       *       *       *       *       *

His voice rose. He glared about at the others. He threw back his head
suddenly and laughed, and the laughter echoed and re-echoed off the
steel walls.

"I say let's die now!" Carhill cried. "There's no use going on. Hugh
was right, as usual. We shouldn't have tried to come back. We've been
fools, all these years, thinking we had a world to come home to."

The people muttered, crowded closer. They pushed into the observation
room, shoved nearer to it in the outside corridor. They muttered in a
rising note of panic as the numbing shock that gripped them gave way.

"Why not die here?" Martha Carhill's voice rose shrill above the sound
of her husband's laughter. "We should have died here millions of years
ago!"

Hugh McCann looked at her and at Amos and at all the others. He
sighed. Why not? Why go on? There was no answer. Even a pragmatist
gave up eventually, when the facts were all against him.

He glanced down at the reports on the table. All the routine reports,
gathered together into routine form, written up in routine
terminology. Reports on an Earth-type planet that just happened to be
the Earth itself.

And then, quite suddenly, the obvious, satisfactory answer came to
him. The factors clicked into place, and he wondered why he hadn't
thought of them long ago. He looked up from the reports, at the people
on the verge of panic, and he knew what to say to quiet them. He had
the factors now.

"No!" he cried. "You're wrong. There's no reason at all to assume that
our race is dead!"

Amos Carhill stopped laughing and stared at him and the others stared
also and none of them believed him at all.

"It's simple!" he cried. "Why has so much time passed outside the ship
while to us only fifty-three years have gone by?"

"Because we traveled too fast," Carhill said flatly. "That's why."

"Yes," Hugh said softly. "But there's one thing we've been forgetting.
What we did, others could do also. Probably lots of expeditions
started out after we left, all trying for the speed of light."

They stared at him. Slowly the dazed look died out of their eyes as
they realized what he meant, and what the concept might mean to them.
The concept of other ships, following them out into time. The concept
of other men, also millions of years from the Earth they had left.

"You mean," Carhill said slowly, "that you believe other people got
caught in the same trap we did--that there may be others _in this time
also_?"

Hugh nodded. "Why not? Maybe they colonized some of those Earth-type
planets we checked on. Anyway, we can look for them."

"No." Carhill shook his head. "If any of them had started after us we
would have crossed their paths already. We never have. We never found
a trace of any other expedition. Even if there is another, even if
there are colonies somewhere, we could spend another fifty years
looking."

"Well," Martha Carhill whispered. "Why not? It would give us something
to look for."

Hugh McCann glanced around the circle of faces and saw the new hope
that came into them, the new belief that sprang into existence so
quickly because they wanted to believe. He smiled, somewhat sadly, and
picked up the pile of reports and the photographs he had just
developed. Then he slipped out of the room, through the crowd outside,
away from them and the rising hum of their voices. He didn't need to
say anything more. The ship would go on.

       *       *       *       *       *

"Hugh, is that you?"

"Yes, Nora."

She was waiting for him in the corridor. She came up to him and smiled
and slipped her arm through his. They walked on together, down the
hall past the last of the people.

"I heard what you said, Hugh. You convinced them."

He nodded. "I wonder why it took me so long to think of it."

The voices died away behind them. They were all alone. They rounded a
corner where a viewscreen picked up the image of the moon, so
familiar, now the only thing that was familiar about this Earth. Nora
shivered.

"You were very logical, Hugh. But I didn't believe you."

He glanced around and saw that there was no one near them and that the
communicators in this part of the ship were turned off. Only then did
he answer her.

"I didn't believe myself, Nora."

"Tell me."

"When we're outside."

They went down the winding ramp that led to the interior of the ship.
It too was deserted now. They left the carpeted, muffled corridors and
their footsteps rang on the steel plates that lay down the middle of
the ship, its heart, where the energy converters were, and the
disposal units, and the plant rooms, and the great glass spheres of
the hydroponics tanks.

"It's ironic, isn't it?" Nora said slowly. "We left here so long ago,
looking for worlds with life, and we come back to find our own world
dead."

"It's ironic, all right." He walked along the row of tanks until he
came to the one he was searching for, and then he picked up a glass
cylinder and filled it from the tank.

"I had to tell them something, Nora. They couldn't have gone on,
otherwise."

The bottle was full. He stoppered it and then turned away. They
crossed to the nearest lock and he pushed the button that opened it.
They waited a few minutes until the door came open, and then they went
out, down the ramp to the ground, across the slippery rocks. Even
through the clouds there was enough light to see by.

"It's warm," she said.

"It always is, now."

They were approaching the ocean. The surf beat loudly in their ears.
The spray was warm against their faces, almost as warm as the night
wind.

"Tell me," she said. "You know what really happened, don't you?"

"I think so. I can't really be sure."

They paused on the low ledge where he had stood earlier and watched
the girls gather their data for the reports. At their feet the waves
washed up to the edges of the tide pools, eddying into and out of them
softly. The water looked dark and cold, but they knew that it too was
warm.

"There've been lots of changes, and they all fit a pattern," he said.
"The temperature. The difference in salt content in the water. The
higher tides. Those things could happen for several reasons. But
there's only one explanation for the other changes, the ones I found
on the star charts."

She waited. The water lapped in and out, reaching almost to where they
stood.

"The Earth rotates faster now," he said. "And the stars are nearer.
Much nearer than they were."

"Isn't that impossible?"

"How do we know? We exceeded the speed of light. Who could say what
continuum that might have put us in? I remember an analogy I read
once, in a layman's book on different theories of space-time. '--The
future and the past, two branches of a hyperbola, each with the speed
of light as its limit--'"

"You mean," she whispered, "that we're not in the future at all? We're
in the past--the far past--before there was any life on Earth?"

       *       *       *       *       *

He looked down at the pools of water at their feet, the lifeless water
that according to all their old discarded theories should have been
teeming with life. He nodded slowly and lifted the glass cylinder he
had brought from the ship and stared at it.

"That bottle," she whispered. "You filled it with bacteria, didn't
you?"

He nodded again.

"You're mad, Hugh. You can't mean that _that bottle_ is the origin of
life on Earth! You can't."

"Maybe this isn't our Earth, Nora. Maybe there are thousands of
continuums and thousands of Earths, all waiting for a ship to land
someday and give them life."

Slowly he unstoppered the cylinder and knelt down at the water's edge.
For a minute he paused, wondering if there were other continuums or
only this one, wondering just how deep the paradox lay. Then he tipped
the bottle up and poured, and the liquid from the cylinder ran down
into the tide pools and eddied there and was lost in the liquid of the
ocean. He poured until the bottle was empty and all the single-celled
bacteria from the ship's tank mingled with the warm, lifeless waters.

The water temperatures were the same. Everything was the same, and the
conditions were very favorable and the bacteria would divide and
redivide and keep on dividing for millions of years.

"We'll hold the ship under light speed," he said. "And in a few
million years we can drop back here and see how evolution is getting
along."

He stood up and she took his hand and moved closer to him. They were
both shivering, despite the warmth of the air.

"But how did life originate in the beginning?" she asked suddenly.

Hugh McCann shook his head in the darkness. "I don't know. We've been
all over the galaxy and haven't found life anywhere. Perhaps it can't
have a natural cause. Perhaps it's always planted. A closed circle
from beginning to end."

"But something--someone--must have started the circle. Who?"

He looked down at the empty cylinder that he had dropped at the
water's edge and then he looked out at the ocean, lifeless no longer.
And once again he shook his head.

"We did, Nora. We're the beginning."

For a long moment their eyes met and held, and then they turned and
walked away from the ocean, back toward the ship, and the people. And
the moonlight glinted off the empty bottle.

THE END

       *       *       *       *       *