"Born of the next larger size. After all, we're environment,
too--perhaps the harshest the beasts have yet faced."
Hafner was a practical man, trained to administer a colony. Concepts
were not his familiar ground. "Mutations, then? But I thought--"
The biologist smiled. It was thin and cracked at the edges of his
mouth. "On Earth, it would be mutation. Here it is merely normal
evolutionary adaptation." He shook his head. "I never told you, but
omnivores, though they could be mistaken for an animal from Earth,
have no genes or chromosomes. Obviously they do have heredity, but how
it is passed down, I don't know. However it functions, it responds to
external conditions far faster than anything we've ever encountered."
Hafner nodded to himself. "Then we'll never be free from pests." He
clasped and unclasped his hands. "Unless, of course, we rid the
planet of all animal life."
"Radioactive dust?" asked the biologist. "They have survived worse."
The exec considered alternatives. "Maybe we should leave the planet
and leave it to the animals."
"Too late," said the biologist. "They'll be on Earth, too, and all the
planets we've settled on."
Hafner looked at him. The same pictures formed in his mind that Marin
had thought of. Three ships had been sent to colonize Glade. One had
remained with the colonists, survival insurance in case anything
unforeseen happened. Two had gone back to Earth to carry the report
that all was well and that more supplies were needed. They had also
carried specimens from the planet.
The cages those creatures were kept in were secure. But a smaller
species could get out, must already be free, inhabiting, undetected,
the cargo spaces of the ships.
There was nothing they could do to intercept those ships. And once
they reached Earth, would the biologists suspect? Not for a long time.
First a new kind of rat would appear. A mutation could account for
that. Without specific knowledge, there would be nothing to connect it
with the specimens picked up from Glade.
[Illustration]
"We have to stay," said the biologist. "We have to study them and we
can do it best here."
He thought of the vast complex of buildings on Earth. There was too
much invested to tear them down and make them verminproof. Billions of
people could not be moved off the planet while the work was being
done.
They were committed to Glade not as a colony, but as a gigantic
laboratory. They had gained one planet and lost the equivalent of ten,
perhaps more when the destructive properties of the omnivores were
finally assessed.
A rasping animal cough interrupted the biologist's thoughts. Hafner
jerked his head and glanced out the window. Lips tight, he grabbed a
rifle off the wall and ran out. Marin followed him.
* * * * *
The exec headed toward the fields where the second fast crop was
maturing. On top of a knoll, he stopped and knelt. He flipped the dial
to _extreme charge_, aimed, and fired. It was high; he missed the
animal in the field. A neat strip of smoking brown appeared in the
green vegetation.
He aimed more carefully and fired again. The charge screamed out of
the muzzle. It struck the animal on the forepaw. The beast leaped high
in the air and fell down, dead and broiled.
They stood over the animal Hafner had killed. Except for the lack of
markings, it was a good imitation of a tiger. The exec prodded it with
his toe.
"We chase the rats out of the warehouse and they go to the fields," he
muttered. "We hunt them down in the fields with dogs and they breed
tigers."
"Easier than rats," said Marin. "We can shoot tigers." He bent down
over the slain dog near which they had surprised the big cat.
The other dog came whining from the far corner of the field to which
he had fled in terror. He was a courageous dog, but he could not face
the great carnivore. He whimpered and licked the face of his mate.
The biologist picked up the mangled dog and headed toward the
laboratory.
"You can't save her," said Hafner morosely. "She's dead."
"But the pups aren't. We'll need them. The rats won't disappear merely
because tigers have showed up."
The head drooped limply over his arm and blood seeped into his
clothing as Hafner followed him up the hill.
"We've been here three months," the exec said suddenly. "The dogs have
been in the fields only two. And yet the tiger was mature. How do you
account for something like that?"
Marin bent under the weight of the dog. Hafner never would understand
his bewilderment. As a biologist, all his categories were upset. What
did evolution explain? It was a history of organic life on a
particular world. Beyond that world, it might not apply.
Even about himself there were many things Man didn't know, dark
patches in his knowledge which theory simply had to pass over. About
other creatures, his ignorance was sometimes limitless.
Birth was simple; it occurred on countless planets. Meek grazing
creatures, fierce carnivores--the most unlikely animals gave birth to
their young. It happened all the time. And the young grew up, became
mature and mated.
He remembered that evening in the laboratory. It was accidental--what
if he had been elsewhere and not witnessed it? They would not know
what little they did.
He explained it carefully to Hafner. "If the survival factor is high
and there's a great disparity in size, the young need not ever be
young. They may be born as fully functioning adults!"
* * * * *
Although not at the rate it had initially set, the colony progressed.
The fast crops were slowed down and a more diversified selection was
planted. New buildings were constructed and the supplies that were
stored in them were spread out thin, for easy inspection.
The pups survived and within a year shot up to maturity. After proper
training, they were released to the fields where they joined the older
dogs. The battle against the rats went on; they were held in check,
though the damage they caused was considerable.
The original animal, unchanged in form, developed an appetite for
electrical insulation. There was no protection except to keep the
power on at all times. Even then there were unwelcome interruptions
until the short was located and the charred carcass was removed.
Vehicles were kept tightly closed or parked only in verminproof
buildings. While the plague didn't increase in numbers, it couldn't be
eliminated, either.
There was a flurry of tigers, but they were larger animals and were
promptly shot down. They prowled at night, so the colonists were
assigned to guard the settlement around the clock. Where lights failed
to reach, the infra-red 'scope did. As fast as they came, the tigers
died. Except for the first one, not a single dog was lost.
The tigers changed, though not in form. Externally, they were all big
and powerful killers. But as the slaughter went on, Marin noticed one
astonishing fact--the internal organic structure became progressively
more immature.
The last one that was brought to him for examination was the
equivalent of a newly born cub. That tiny stomach was suited more for
the digestion of milk than meat. How it had furnished energy to drive
those great muscles was something of a miracle. But drive it had, for
a murderous fifteen minutes before the animal was brought down. No
lives were lost, though sick bay was kept busy for a while.
That was the last tiger they shot. After that, the attacks ceased.
The seasons passed and nothing new occurred. A spaceship civilization
or even that fragment of it represented by the colony was too much for
the creature, which Marin by now had come to think of as the
"Omnimal." It had evolved out of a cataclysmic past, but it could not
meet the challenge of the harshest environment.
Or so it seemed.
* * * * *
Three months before the next colonists were due, a new animal was
detected. Food was missing from the fields. It was not another tiger:
they were carnivorous. Nor rats, for vines were stripped in a manner
that no rodent could manage.
The food was not important. The colony had enough in storage. But if
the new animal signaled another plague, it was necessary to know how
to meet it. The sooner they knew what the animal was, the better
defense they could set up against it.
Dogs were useless. The animal roamed the field they were loose in, and
they did not attack nor even seem to know it was there.
The colonists were called upon for guard duty again, but it evaded
them. They patrolled for a week and they still did not catch sight of
it.
Hafner called them in and rigged up an alarm system in the field most
frequented by the animal. It detected that, too, and moved its sphere
of operations to a field in which the alarm system had not been
installed.
Hafner conferred with the engineer, who devised an alarm that would
react to body radiation. It was buried in the original field and the
old alarm was moved to another.
Two nights later, just before dawn, the alarm rang.
Marin met Hafner at the edge of the settlement. Both carried rifles.
They walked; the noise of any vehicle was likely to frighten the
animal. They circled around and approached the field from the rear.
The men in the camp had been alerted. If they needed help, it was
ready.
They crept silently through the underbrush. It was feeding in the
field, not noisily, yet they could hear it. The dogs hadn't barked.
They inched nearer. The blue sun of Glade came up and shone full on
their quarry. The gun dropped in Hafner's hand. He clenched his teeth
and raised it again.
Marin put out a restraining arm. "Don't shoot," he whispered.
"I'm the exec here. I say it's dangerous."
"Dangerous," agreed Marin, still in a whisper. "That's why you can't
shoot. It's more dangerous than you know."
Hafner hesitated and Marin went on. "The omnimal couldn't compete in
the changed environment and so it evolved mice. We stopped the mice
and it countered with rats. We turned back the rat and it provided the
tiger.
"The tiger was easiest of all for us and so it was apparently stopped
for a while. But it didn't really stop. Another animal was being
formed, the one you see there. It took the omnimal two years to create
it--how, I don't know. A million years were required to evolve it on
Earth."
Hafner hadn't lowered the rifle and he showed no signs of doing so.
He looked lovingly into the sights.
"Can't you see?" urged Marin. "We can't destroy the omnimal. It's on
Earth now, and on the other planets, down in the storage areas of our
big cities, masquerading as rats. And we've never been able to root
out even our own terrestrial rats, so how can we exterminate the
omnimal?"
"All the more reason to start now." Hafner's voice was flat.
Marin struck the rifle down. "Are their rats better than ours?" he
asked wearily. "Will their pests win or ours be stronger? Or will the
two make peace, unite and interbreed, make war on us? It's not
impossible; the omnimal could do it if interbreeding had a high
survival factor.
"Don't you still see? There is a progression. After the tiger, it bred
this. If this evolution fails, if we shoot it down, what will it
create next? This creature I think we can compete with. _It's the one
after this that I do not want to face._"
* * * * *
It heard them. It raised its head and looked around. Slowly it edged
away and backed toward a nearby grove.
The biologist stood up and called softly. The creature scurried to the
trees and stopped just inside the shadows among them.
The two men laid down their rifles. Together they approached the
grove, hands spread open to show they carried no weapons.
It came out to meet them. Naked, it had had no time to learn about
clothing. Neither did it have weapons. It plucked a large white flower
from the tree and extended this mutely as a sign of peace.
"I wonder what it's like," said Marin. "It seems adult, but can it be,
all the way through? What's inside that body?"
"I wonder what's in his head," Hafner said worriedly.
It looked very much like a man.
--F. L. WALLACE
* * * * *