SKIT-TREE PLANET

                          By MURRAY LEINSTER

           [Transcriber's Note: This etext was produced from
                 Thrilling Wonder Stories, April 1947.
         Extensive research did not uncover any evidence that
         the U.S. copyright on this publication was renewed.]


The communicator-phone set up a clamor when the sky was just beginning
to gray in what, on this as yet unnamed planet, they called the east
because the local sun rose there. The call-wave had turned on the set.
Bob Wentworth kicked off his blankets and stumbled from his bunk in the
atmosphere-flier, and went sleepily forward to answer. He pushed the
answer-stud.

"Hello, what's the trouble?" he said wearily. "Talk louder, there's
some static. Oh--No, there's no trouble. Why should there be? The devil
I'm late reporting! Haynes and I obeyed orders and tried to find the
end of a confounded skit-tree plantation. We chased our tails all day
long, but we made so much westing that we gained a couple of hours
light. So it isn't sunrise yet, where we are."

Wentworth yawned as he listened.

"Oh, we set down the flier on a sort of dam and went to sleep,"
he answered. "No, nothing happened. We're used to feeling creepy.
We thrive on it. Haynes says he's going to do a sculpture group
of a skit-tree planter which will be just an eye peeking around a
tree-trunk. No! Hang it, no!

"We photographed a couple of hundred thousand square miles of
skit-trees growing in neat rows, and we photographed dams, and canals,
and a whole irrigation system, but not a sign of a living creature.
No cities, no houses, no ruins, no nothing. I've got a theory, McRae,
about what happened to the skit-tree planters."

He yawned again.

"Yeah. I think they built up a magnificent civilization and then found
a snark. Snark! SNARK. Yes. And the snark was a boojum." He
paused. "So they silently faded away."

He grinned at the profanity that came out of the communicator-speaker.
Then--back at the irreverently nicknamed _Galloping Cow_ which was the
base ship of the Extra-Solarian Research Institute expedition to this
star-cluster--McRae cut off.

Wentworth stretched, and looked out of the atmosphere-flier's windows.
He absently noticed that the static on the communication-set kept up,
which was rather odd on a FM receiver. But before the fact could have
any meaning, he saw something in motion in the pale gray light of dawn.
He squinted. Then he caught his breath.

He stood frozen until the moving object vanished. It moved, somehow, as
if it carried something. But it was bigger than the _Galloping Cow_!
Only after it vanished did he breathe again, and then he licked his
lips and blinked.

Haynes' voice came sleepily from the bunk-space of the flier.

"What's from the _Galloping Cow_? Planning to push off for Earth?"

Wentworth took a deep breath and stared where the moving thing had gone
out of sight.

"No," he said then, very quietly. "McRae was worried because we hadn't
reported. It's two hours after sunrise back where the ship is." He
swallowed. "Want to get up now?"

"I could do with coffee," said Haynes, "pending a start for home."

       *       *       *       *       *

Wentworth heard him drop his feet to the floor. Bob Wentworth pinched
himself and winced, and swallowed again, and then twisted the opener
of a beverage can labeled _Coffee_, and it began to make bubbling
noises. He put it aside to heat and brew itself, and pulled out two
breakfast-rations. He put them in the readier. Finally he stared again
out the flier's window.

The light outside grew stronger. To the north--if where the sun rose
was east--a low but steep range of mountains began just beyond the spot
where the flier had landed for the night. It had settled down on a
patently artificial embankment of earth, some fifty feet high, that ran
out toward the skit-tree sea from one of the lower mountain spurs. The
moving thing had gone into those mountains, as if it carried something.
But it was bigger.

Haynes came forward, yawning.

"I feel as if this were going to be a good day," he said, and yawned
again. "I wish I had some clay to mess with. I might even do a portrait
bust of you, Wentworth, lacking a prettier model."

"Keep an eye out the window," said Wentworth. "Meanwhile you might set
the table."

He went back to his bunk and dressed quickly. His expression was blank
and incredulous. Once more he pinched himself. Yes, he was awake. He
went back to where steaming coffee and the breakfast-platters waited on
the board normally used for navigation.

The communication-set still emitted static, curiously steady, scratchy
noise that should not have come in on a frequency-modulation set at
all. It should not have come in especially on a planet which had
plainly once been inhabited, but whose every inhabitant and every
artifact had vanished utterly.

Habitation was so evident, and seemed to have been so recent, that most
of the members of the expedition felt a creepy sensation as if eyes
were watching them all the time. But that was absurd, of course.

Haynes ate his chilled fruit. The readier had thawed the frozen fruit,
and not only thawed but cooked the rest of breakfast. Wentworth drank a
preliminary cup of coffee.

"I've just had an unsettling experience, Haynes," he said carefully.
"Do I look unusually cracked, to you?"

"Not for you," said Haynes. "Not even for any man who not only isn't
married but isn't even engaged. I attribute my splendid mental health
to the fact that I'm going to get married as soon as we get back to
Earth. Have I mentioned it before?"

Wentworth ignored the question.

"Something's turned up--with a reason back of it," he said in a queer
tone. "Check me on this. We found the first skit-trees on Cetis Alpha
Three. They grew in neat rows that stretched out for miles and miles.
They had patently been planted by somebody who knew what he was doing,
and why.

"We also found dams, and canals, and a complete irrigation system.
We found places where ground had been terraced and graded, and where
various trees and plants grew in what looked like a cockeyed form of
decorative planting.

"Those clearings could have been sites for cities, only there were no
houses or ruins, or any sign that anything had ever been built there.
We hunted that planet with a fine-toothed comb, and we'd every reason
to believe it had recently been inhabited by a highly civilized race.
But we never found so much as a chipped rock or a brick or any shaped
piece of metal or stone to prove it.

"We found out a civilization had existed, and it had vanished, and when
it vanished it took away everything it had worked with, except that it
didn't tear up its plantings or put back the dirt it had moved. Right?"

"Put dispassionately, you sound like you're crazy," said Haynes
cheerfully. "But you're recounting facts. Okay so far."

"McRae tore his hair because he couldn't take back anything but
photographs," Wentworth went on. "Oh, you did a very fine sculpture of
a skit-tree fruit, but we froze some real ones for samples, anyhow.
We went on to another solar system. And on a planet there, we found
skit-trees planted in neat rows reaching for miles and miles, and dams,
and canals, and cleared places--and nothing else. McRae frothed at the
mouth with frustration. Some non-human race had space-travel. Eh?"

Haynes took a cup of coffee.

"The inference," he agreed, "was made unanimously by all the personnel
of the _Galloping Cow_."

       *       *       *       *       *

Nervously Wentworth glanced out the flier window.

"We kept on going. On nine planets in seven solar systems, we found
skit-tree plantations with rows up to six and seven hundred miles
long--following great-circle courses, by the way--and dams and
irrigation systems. Whoever planted those skit-trees had space-travel
on an interstellar scale, because the two farthest of the planets were
two hundred light-years apart. But we've never found a single artifact
of the race that planted the skit-trees."

"True," said Haynes. "Too true! If we'd loaded up the ship with
souvenirs of the first non-human civilized race ever to be discovered,
we'd have headed for home and I'd be a married man now."

"Listen!" Wentworth said painfully. "Could it be that we never found
any artifacts because there weren't any? Could it be that a creature--a
monstrous creature--could have developed instincts that led it to make
dams and canals like beavers do, and plantings like some kind of ants
do, only with the sort of geometric precision that is characteristic
of a spider's web? Could we have misread mere specialized instinct as
intelligence?"

Haynes blinked.

"No," he said. "There's seven solar systems, two hundred light-years
apart, and a specific species, obviously originating on only one
planet, spread out over two hundred light-years. Not unless your animal
could do space-travel and carry skit-tree seeds with him. What gave you
that idea?"

"I saw something," said Wentworth. He took another deep breath. "I'm
not going to tell you what it was like, I don't really believe it
myself. And I am scared green! But I wanted to clear that away before I
mentioned--this. Listen!"

He waved his hand at the communicator-set. Static came out of its
speaker in a clacking, monotonous, but continuous turned-down din.

Haynes listened.

"What the devil? We shouldn't get that kind of stuff on a
frequency-modulation set!"

"We shouldn't. Something's making it. Maybe what I saw
was--domesticated. In any case I'm going to go out and look for tracks
at the place where I saw it moving."

"You? Not me? What's the matter with both of us?"

Wentworth shook his head.

"I'll take a flame-pistol, though running-shoes would be more
appropriate. You can hover overhead, if you like. But don't try to be
heroic, Haynes."

Haynes whistled.

"How about air reconnaissance first?" he demanded. "We can look for
tracks with a telescope. If we see a jabberwock or something on that
order, we can skip for the blue. If we don't find anything from the
air, all right. But a preliminary scout from aloft would be wiser."

"That might be sensible," Wentworth admitted. "But the cussed thing
scared me so that I've got to face it sooner or later. All right. Clear
away this stuff and I'll take the ship up."

While Haynes slid the cups and platters into the refuse-disposal
unit, he seated himself in the pilot's seat, turned off the watch-dog
circuit that would have waked them if anything living had come within
a hundred yards of the flier during the nighttime. Then he gave the
jets a warming-up flow of fuel. Thirty seconds later, the flier lifted
smoothly and leveled off to hover at four hundred feet. Wentworth took
bearings on their landing-place. There were no other landmarks that
would serve as guides for keeping the flier stationary.

The skit-trees began where the ground grew fairly level, and they went
on beyond the horizon. They were clumps of thin and brittle stalks
which rose straight up for eighty feet and then branched out and bore
copious quantities of a fruit for which no human being could imagine
any possible use.

Each clump of trees was a geometrically perfect circle sixty feet
in diameter. There were always just ninety-two feet between clumps.
They reached out in rows far beyond the limit of vision. Only the day
before, the flier had covered fifteen hundred miles of westing without
coming to the end of this particular planting.

       *       *       *       *       *

With the flier hovering, Wentworth used a high-power telescope to
search below. He hunted for long, long minutes, examining minutely
every square foot of half a dozen between-clump aisles without result.
There was no sign of the passage of any creature, much less of the
apparition he would much rather not believe in.

"I think I'm going to have to go down and hunt on foot," he said
reluctantly. "Maybe there wasn't anything. Maybe I'm crazy."

Haynes spoke in mild tones.

"Speaking of craziness, is or isn't that city yonder a delusion?" he
asked.

He pointed, and Wentworth jerked about. Many, many miles away,
something reared upward beyond the horizon. It was indubitably a city,
and they had searched nine planets over without finding a single scrap
of chipped stone to prove the reality of the skit-tree planters.

Wentworth could see separate pinnacles and what looked like skyways
connecting them far above-ground. He snapped his camera to his
binoculars and focussed them, and of course, the camera with them. He
saw architectural details of bewildering complexity. He snapped the
shutter of his camera.

"That gets top priority," said Wentworth. "There's no doubt about this!"

The thing he had seen before sunrise was so completely incredible that
it was easier to question his vision than to believe in it. He flung
over the jet-controls so that the drive-jets took the fuel from the
supporting ones. The flier went roaring toward the far-away city.

[Illustration: Wentworth sent the scout flier zooming in the direction
of the mysterious city.]

"Take over," he told Haynes. "I'm going to call McRae back. He'll break
down and cry with joy."

He pushed the call-button. Seconds later a voice came out of the
communicator, muffled and made indistinct by the roar of the jets.
Wentworth reported. He turned a tiny television scanner on the huge,
lacy construction rising from a site still beyond the horizon. McRae's
shout of satisfaction was louder than the jets. He bellowed and cut off
instantly.

"The _Galloping Cow_ is shoving off," said Wentworth. "McRae's giving
this position and telling all mapping-parties to make for it. And he'll
climb out of atmosphere to get here fast. He wants to see that city."

The flier wabbled, as Haynes' hands on the controls wabbled.

"What city?" he asked in an odd voice.

Wentworth stared unbelievingly. There was nothing in sight but the
lunatic rows of skit-trees, stretching out with absolutely mechanical
exactitude to the limit of vision on the right, on the left, ahead, and
behind to the very base of the mountains. There simply wasn't any city.
Wentworth gaped.

"Pull that film out of the camera. Take a look at it. Were we seeing
things?"

Haynes pulled out the already-developed film. The city showed plainly.
It had gone on television to the _Galloping Cow_, too. It had not been
an illusion. Wentworth pushed the call-button again as the flier went
on toward a vanished destination. After a moment he swore.

"McRae lost no time. He's out of air already, and our set won't reach
him. Where'd that city go?"

He set the supersonic collision-alarm in action. The radar. They
revealed nothing. The city no longer existed.

They searched incredulously for twenty minutes, at four hundred miles
an hour. The radar picked up nothing. The collision-alarm picked up no
echoes.

"It was here!" growled Wentworth. "We'll go back and start over."

He sent the flier hurtling back toward the hills and the embankment
where it had rested during the night. The communicator rasped a sudden
furious burst of static. Wentworth, for no reason whatever, jerked his
eyes behind. The city was there again.

Haynes photographed it feverishly as the flier banked and whirled back
toward it. For a full minute it was in plain view, and the static was
loud. Then the static cut off. Simultaneously, the city vanished once
more.

       *       *       *       *       *

Again a crazy circling. But the utterly monotonous landscape below
showed no sign of a city-site, and it was impossible to be sure that
the flier actually quartered the ground below, or whether it circled
over the same spot again and again, or what.

"If McRae turns up in the _Galloping Cow_," said Haynes, "and doesn't
find a blamed thing, maybe he'll think we've all gone crazy and had
better go home. And then--"

"Then you'll get married!" Wentworth finished savagely. "Skip it! I've
got an idea! Back to the mountains once more."

The flier whirled yet again and sped back toward its night's
resting-place. Ten miles from it, and five thousand feet up, the static
became still again.

Wentworth kicked a smoke-bomb release and whirled the flier about so
sharply that his head snapped forward from the sudden centrifugal force.

There was the city.

The flier roared straight for it. Static rattled out of the
communicator. One minute. Two. He kicked the smoke-bomb release again.
Already the first bomb had hit ground and made a second smoke-signal.
Ten miles on, he dropped a third.

The smoke-signals would burn for an hour, and give him a perfect line
on the vanishing city. This time it did not vanish. It grew larger and
larger, and details appeared, and more details.

It was a unit--a design of infinite complexity, perfectly integrated.
Story upon story, with far-flung skyways connecting its turrets, it was
a vision of completely alien beauty. It rose ten thousand feet from the
skit-trees about its base. Its base was two miles square.

"They build high," said Wentworth grimly, "so they won't use any extra
ground they could plant their confounded skit-trees on. I'm going to
land short of it, Haynes."

The vertical jets took over smoothly as he cut the drive. The flier
slowed, and two blasts forward stopped it dead, and then it descended
smoothly. Wentworth had checked not more than a hundred yards from the
outermost tower. It appeared to be made of completely seamless metal,
incised with intricate decorative designs. Which was incredible.

But the most impossible thing of all was that there was no movement
anywhere. No stirring. No shifting. Not even furtive twinklings as
of eyes peering from the strangely-shaped window openings. And when
the flier landed gently between two circular clumps of skit-trees and
Wentworth cut off the jets and turned off even the communicator--then
there was silence.

The silence was absolute. Two miles high, near them towered a city
which could house millions of people. And it was utterly without noise
and utterly without motion in any part.

"And the prince went into the castle," said Wentworth savagely. "He
kissed the Sleeping Beauty on the lips, and she opened her eyes with a
glad little cry, and they were married and lived happily ever after.
Coming, Haynes?"

"Sure thing," said Haynes. "But I don't kiss anybody. I'm engaged!"

Wentworth got out of the flier. Never yet had they found a single
dangerous animal on any of the nine planets on which skit-trees grew,
with the possible exception of whatever it was he had seen that
morning. Whoever planted skit-trees had wiped out dangerous fauna.
That had been one of the few seeming certainties. But all the same,
Wentworth put a flame-pistol in his belt before he ventured into the
city.

He stopped short. There was a flickering. The city was blotted out. A
blank metal wall stood before him. It reared all around the flier and
the men in it. Between them and the city. Shining, seamless, gleaming
metal, circular and a hundred feet high. It neatly enclosed a space two
hundred yards across, and hence some clumps of skit-trees with the
men. "Now, where the devil did that come from?" asked Wentworth.

Abruptly everything went black. There was darkness. Absolute, opaque.

       *       *       *       *       *

For perhaps two seconds it was unbroken. Then Haynes, still in the
flier, pushed the button that turned on the emergency landing-lights.
Twin beams of some hundreds of thousands candlepower lashed out, and
recoiled from polished metal, and spread around and were reflected and
re-reflected. There was a metal roof atop the circular metal wall. Men
and flier and clumps of skit-trees were sealed up in a monstrous metal
cylinder. Wentworth cried furiously:

"It isn't so! It simply can't be so!"

He marched angrily to the nearest of the metal walls. Twin shadows of
his figure were cast on before him by the landing-light beams. Weird
reflections of the shadows and the lights--distorted crazily by the
polished surface--appeared on every hand.

He reached the metal wall. He pulled out his flame-pistol and
tapped at it. The wall was solid. He backed off five paces and sent
a flame-pistol beam at it. The flame splashed from the metal in a
coruscating shower. But nothing happened. Absolutely nothing. When he
turned off the pistol the metal was unmarred. It was not even red-hot.

"The sleeping beauty woke up, Wentworth," Haynes said. "What's the
matter?"

He saw Wentworth gazing with stupefaction at a place where the metal
cylinder touched ground. There was the beginning of a circular clump of
skit-trees. And he saw a stalk at a slight angle. It came out of the
metal wall. The skit-trees were in the wall. They came out of it. He
saw another that went into it.

He went back to the flier and climbed in. He turned the communicator
up to maximum power. The racket that came out of it was deafening. He
punched the call-button. Again and again and again. Nothing happened.
He turned the set off. The dead stillness which followed was daunting.

"Well?" said Haynes.

"It's impossible," said Wentworth, "but I can explain everything. That
wall isn't real."

"Then we ram through it?"

"We'd kill ourselves!" Wentworth told him, exasperated. "It's solid!"

"Not real, but solid?" asked Haynes. "A bit unusual, that. When I get
back to Earth and am a happily married man, I'll try to have a more
plausible story than that to tell my wife if I ever come home late, not
that I ever will."

Wentworth looked at him. And Haynes grinned. But there was sweat on his
face. Wentworth grunted.

"I'm scared too, but I don't make bad jokes to cover up," he said
sourly. "This can be licked. It's got to be!"

"What is it?"

"How do I know?" demanded Wentworth. "It makes sense, though. A city
that vanishes and re-appears, apparently without anybody in it.
That doesn't happen. This can--this tank we're in. There wasn't any
machinery around to put up a wall like this.

"The top wasn't heaved into place either. It wasn't lowered down to
seal us in. It didn't slide into position. One instant it wasn't there,
and the next instant it was. Like something that--hm--had materialized
out of nowhere. Maybe that's it! And the city was the same sort of
trick! Maybe that's the secret of this whole civilization we're trying
to trace!"

His voice echoed weirdly against the metal ceiling on every hand.

"What's the secret?"

"Materializing things! Making a--synthetic sort of matter!
Making--well--force-fields that look and act like substance! Of course!
If you can generate a building, why build one? We can make a magnetic
field with a coil of wire and an electric current. It's just as real as
a brick. It's simply different from a brick.

"We can make a picture on a screen. It's just as real as a painting.
It's just different. Suppose we could make something like a magnetic
field, with shape and coloring and solidity! Why not solidity? Given
the trick, it should be as easy as shape or color!

"If we had a trick like that and wanted to stop some visitors from
outer space, we'd simply construct a solid image of a can around them!
It would be made of energy, and all the energy applied to it would flow
to any threatened spot.

"It would draw power to fight any stress that tried to destroy it. Of
course! And why should we build cities? We'd clear a place for them and
generate them and maintain them simply by supplying the power needed to
keep them in being! We'd make force-fields in the shape of machines, to
dig canals or pile up dams."

       *       *       *       *       *

He had raised his voice as he spoke. The solid walls and roof made
echoes which clanged. He stopped talking.

"Then there wouldn't be any artifacts," Haynes said calmly. "When a
city was abandoned, it would be wiped out as completely as the picture
on a theatre-screen when the play is done with. But Wentworth!"

"Eh?"

"If we had that trick, and we'd captured some meddlesome strangers from
outer space by clapping a can over them, what would we do?" He paused.
"In other words, what comes next for us?"

"Get in the pilot's seat," he commanded. "Put your finger on the
vertical flight-button. When you see light, stab it down so we'll shoot
straight up! If we trapped somebody, and if we lifted the trap we'd
have something worse than a trap to take care of them with. They'd do
the same, and they've got what it should take!"

Silence followed.

"Such as?" Haynes asked at last.

"I saw one Thing this morning," said Wentworth grimly. "I don't like
to think about it. If they're bringing it over to snap us up when this
can is lifted off us, we're up against plenty of trouble. You keep your
finger on the flight-button! That Thing was bigger than the _Galloping
Cow_! I'll try to tip McRae off as to what's happened."

He settled down by the communicator. Every ten minutes he tried to call
the expedition's ship. Every time there came a monstrous roar of static
as the set came on, and no other sound at all. Aside from that, nothing
happened. Absolutely nothing.

The flier lay on the ground with an unnatural assortment of reflected
and re-reflected light-beams from the twin landing-lamps. There were
four clumps of skit-trees sharing the prison with the flier and the men.

Silence. Stillness. Nothing. Every ten minutes Wentworth called the
_Galloping Cow_. It was an hour and a half before there came an answer
to Wentworth's call.

"--llo!" came McRae's voice through the crackling static. "Down
in--gain--no sign--sort anywhere--"

"Get a directional on me!" snapped Wentworth. "Can you hear me above
the static?"

"What sta--voice perfectly clear--" came McRae's booming.
"Keep--talking...."

Wentworth blinked. No static at the _Galloping Cow_? When his ears were
practically deafened? Then it made sense. All of it!

"I'll keep talking!" he said fervently. "Use the directional and
locate me! But don't try to help me direct! Take a bearing from where
you find me to where a fifty-foot dirt embankment sticks out from
a mountain-spur to the north. Get on that line and you'll hear the
static, all right.

"It's in a beam coming right here at me. Follow that static back to the
mountains, and when you find where it's being projected from, you'll
find some skit-tree planters with all the artifacts your little heart
desires. Only maybe you'll have to blast them."

He swallowed.

"It works out to sense," he went on more calmly. "They built up a
civilization based on generating instead of building the things they
wanted to use. Our force-fields are globular, because the generator's
inside. If you want a force-field to have a definite shape, you have
to generate it differently. Their cities and their machines weren't
substance, though they were solid enough. They were force-fields!

"The generators were off at a distance, throwing the force-field
they wanted where they needed it. They projected solidities like we
projected pictures on a screen. They projected their cities. Their
tools. Probably their spaceships too! That's why we never found
artifacts. We looked where installations had been, instead of where
they were generated and flung to the spot where they were wanted.
There's a beam full of static coming from those mountains."

Light! With all the blinding suddenness of an atomic explosion, there
was light. Wentworth had a moment's awareness of sunshine on the
brittle stalks of skit-trees, and then of upward acceleration so fierce
that it was like a blow. The atmosphere-flier hurtled skyward with all
its lift-jets firing full blast, and there was the _Galloping Cow_
lumbering ungracefully through atmosphere at ten thousand feet, some
twelve or more miles away.

       *       *       *       *       *

McRae's voice came out of a communicator which now picked up no static
whatever.

"What the devil?" he boomed. "We saw something that looked like a big
metal tank, and it vanished and you went skyward from where it'd been
like a bat out of a cave."

"Suppose you follow me," said Wentworth grimly. "The skit-tree planters
on this planet, anyhow, don't want us around. By pure accident, I
got a line on where they were. They lured me away from their place by
projecting a city.

"I went to look, and it vanished. I played hide and seek with it until
they changed tactics and let it stay in existence. Maybe they thought
we'd land on it, high up, and get out of the flier to explore.

"Then the city would have vanished and we'd have dropped a mile or two,
hard. But we landed on the ground instead, and they clapped a jail
around us.

"I don't know what they intended, but you came along and they let the
jail vanish to keep you from examining it. And now we'll go talk to
them!"

The flier was streaking vengefully back to the embankment to where only
that morning, before sunrise, Wentworth had seen something he still
didn't like to think about.

The _Galloping Cow_ veered around to follow, with all the elephantine
grace of the animal for which she had been unofficially christened.
She'd been an Earth-Pluto freighter before conversion for the
expedition, and she was a staunch vessel, but not a handy one.

The flier dived for the hills. Wentworth's jaws were hard and angry.
The _Galloping Cow_ trailed, wallowing. The flier quartered back and
forth across the hills, examining every square inch of ground.

Nothing. Absolutely nothing. The search went on. The communicator
boomed.

"They're playing 'possum," McRae's voice said. "We'll land and make a
camp and prepare to hunt on foot."

Wentworth growled angrily. He continued to search. Deeper and deeper
the flier went into the hills, going over and over every bit of
terrain. Then, quite suddenly, the communicator emitted babbling
sounds. Shoutings. Incoherent outcries. From the ship, of course.
There were sudden, whining crashes, electronic cannon going off at
a panic-stricken rate. Then a ghastly crashing sound, and silence.
The flier zoomed until Haynes and Wentworth could see. They paled.
Wentworth uttered a raging cry.

The _Galloping Cow_ had landed. Her ports were open and men had
emerged. But now a Thing had attacked the ship with a ruthless,
irresistible ferocity. It was bigger than the _Galloping Cow_. It stood
a hundred feet high at the shoulder. It was armored and possessed of
prodigious jaws and gigantic teeth. It was all the nightmares of
mechanistic minds rolled into one.

It must have materialized from nothingness, because nothing so huge
could have escaped Wentworth's search. But as Wentworth first looked at
it, the incredible jaws closed on the ship's frame and bit through the
tough plates of beryllium steel as if they had been paper. It tore them
away and flung them aside.

A mainframe girder offered resistance. With an irresistible jerk, the
Thing tore it free. And then it put its claws into the very vitals of
the _Galloping Cow_ and began to tear the old spaceship apart.

The crewmen spilled out and fled. The Thing snapped at one as he went
but returned to its unbelievable destruction. Someone heaved a bomb
into its very jaws, and it exploded, and the Thing seemed not to notice.

Wentworth seized the controls of the flier from Haynes. He dived, not
for the ship, but for the space between the ship and the mountains. He
flung the small craft into crazy, careening gyrations in that space.

And then the communicator shrieked with clacking static. The flier
passed through the beam, but Wentworth flung it back in. He plunged
toward the mountains. He lost the beam, and found it again, and lost it
and found it.

"There!" he said, choking with rage. "Down from the top of that cliff.
There's a hole--a cave-mouth. The beam's coming from there!"

He plunged the flier for the opening, and braked with monstrous jetting
that sent rocket-fumes blindingly and chokingly into the tunnel. The
flier hit, and Wentworth scrambled to the forepart of the little ship
and leaped to the cliff-opening against which it bumped. Then he ran
into the opening, his flame-pistol flaring before him.

       *       *       *       *       *

There was a blinding flash inside. The blue-white flame of a
short-circuit created a gigantic arc. It died. The place was full of
smoke, and something small ran feebly across the small space that
Wentworth could see, and fell, and kicked feebly, and was still.
Wentworth could hear a machine come to a jolting stop. And crouching
there fiercely, he waited for more antagonists.

None came. The fumes drifted out the cave-mouth. Then he could see
the Thing on the floor. Clad in a weirdly constructed space-suit, the
creature he had knocked over was not human and looked very tired. It
was dead. Next he saw an almost typical tight-beam projector, linked
with heavy cables to a scanning device.

He saw a model--all of five feet high--of the city he and Haynes had
tried to reach. The model was of unbelievable delicacy and perfection.
But the scanning system now was focused on a metal object which was a
miniature Thing with claws and jaws and armor.

It was two feet long, and there was a cable control by which its
movements could be directed. A solidity which was controlled by that
ingenious mechanical toy could dig canals, or gather the crop from the
tops of skit-trees--when enlarged in the projection to stand a hundred
feet high at the shoulder--or it could tear apart a spaceship as a
terrier rends a rat.

There was more. Much more. But there had been only the one small
Inhabitant, who wore a space-suit on his own planet. And he was dead.
Haynes' voice came from the flier at the cave-mouth. "Wentworth! What's
happened? Are you alive? What's up?"

Wentworth went out, still in a savage mood. He wanted to see how the
_Galloping Cow_ had withstood the attack. What he had seen last looked
bad.

It was bad. The _Galloping Cow_ was a carcass. Her engines were not
too badly smashed, but her outer shell was scrap-iron, her frame was
twisted wreckage, and there was no faintest hope that they could repair
her.

"And--I'm engaged to be married when we get back," said Haynes,
white-faced. "We'll never get back in that."

       *       *       *       *       *

Less than a month later, though, the _Galloping Cow_ did head for
home. Haynes, unwittingly, had made it possible. Examination of
the solidity-projector revealed its principles, and Haynes--trying
forlornly to make a joke--suggested that he model a statuette of the
last Inhabitant to be projected a mile or two high above the skit-tree
plantations now forever useless.

But he was commissioned to model something else entirely, and in his
exuberance his fancy wandered afar. But McRea dourly permitted the
model to stand, because he was in a hurry to start.

So that, some six weeks from the morning when Wentworth had seen an
impossible Thing moving in the gray dawnlight on an unnamed planet,
the _Galloping Cow_ was almost back in touch with humanity. Two weeks
more, and the outposts of civilization on Rigel would be reached.

A long, skeleton tower had been built out from the old ship's battered
remnant. A scanner scanned, and a beam-type projector projected the
image of Haynes' modeling to form a solid envelope of force-field about
the ship. It was much larger than the original hull had been. There
would be room and to spare on the voyage home. And Haynes was utterly
happy.

"Think!" he said blissfully, in the scanning-room where the force-field
envelope was maintained about the ship. "Two weeks and Rigel! Two
months and home! Two months and one day and I'm a married man!"

Wentworth looked at the small moving object on which the scanners
focused.

"You're a queer egg, Haynes," he said. "I don't believe you ever had a
solemn thought in your head. Do you know what wiped out those people?"

"A boojum?" asked Haynes mildly. "Tell me!"

"The biologists figured it out," said Haynes. "A plague. The last poor
devil wore a space-suit to keep the germs out. It seems that some
wrecked Earth-ship drifted out to where one of their explorers found
it. And they hauled it to ground. They learned a lot, but there were
germs on board they weren't used to. Coryzia, for instance.

"In their bodies it had an incubation period of about six months, and
was highly contagious all the time. Then it turned lethal. They didn't
know about it in time to establish quarantines. No wonder the poor
devil wanted to kill us! We'd wiped out his race!"

"Too bad!" said Haynes. He looked down at the small moving thing he had
modeled for a new hull for the _Galloping Cow_.

"You know," he said blithely, "I like this model! I may not be the best
sculptor in the world--as an amateur I wouldn't expect it. But for
a while after we land on earth, I'm going to be the most famous man
alive."

And he beamed at the jerkily moving object which was the model for the
hull of the _Galloping Cow_. It was twelve hundred feet long, as it was
projected about the old ship's engine-room and remaining portions. It
had a stiffly extended tail and an outstretched neck and curved horns.
Its legs extended and kicked, and extended and kicked.

The _Galloping Cow_, in fact, exactly fitted her name by her outward
appearance, as she galloped Earthward through emptiness.