headed toward the fields where the second fast crop wasmaturing. On top of a knoll, he stopped and knelt. He flipped the dialto _extreme charge_, aimed, and fired. It was high; he missed theanimal in the field. A neat strip of smoking brown appeared in thegreen vegetation.
He aimed more carefully and fired again. The charge screamed out ofthe muzzle. It struck the animal on the forepaw. The beast leaped highin the air and fell down, dead and broiled.
They stood over the animal Hafner had killed. Except for the lack ofmarkings, it was a good imitation of a tiger. The exec prodded it withhis toe.
"We chase the rats out of the warehouse and they go to the fields," hemuttered. "We hunt them down in the fields with dogs and they breedtigers."
"Easier than rats," said Marin. "We can shoot tigers." He bent downover the slain dog near which they had surprised the big cat.
The other dog came whining from the far corner of the field to whichhe had fled in terror. He was a courageous dog, but he could not facethe great carnivore. He whimpered and licked the face of his mate.
The biologist picked up the mangled dog and headed toward thelaboratory.
"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 merelybecause tigers have showed up."
The head drooped limply over his arm and blood seeped into hisclothing as Hafner followed him up the hill.
"We've been here three months," the exec said suddenly. "The dogs havebeen in the fields only two. And yet the tiger was mature. How do youaccount for something like that?"
Marin bent under the weight of the dog. Hafner never would understandhis bewilderment. As a biologist, all his categories were upset. Whatdid evolution explain? It was a history of organic life on aparticular world. Beyond that world, it might not apply.
Even about himself there were many things Man didn't know, darkpatches in his knowledge which theory simply had to pass over. Aboutother creatures, his ignorance was sometimes limitless.
Birth was simple; it occurred on countless planets. Meek grazingcreatures, fierce carnivores--the most unlikely animals gave birth totheir young. It happened all the time. And the young grew up, becamemature and mated.
He remembered that evening in the laboratory. It was accidental--whatif he had been elsewhere and not witnessed it? They would not knowwhat little they did.
He explained it carefully to Hafner. "If the survival factor is highand there's a great disparity in size, the young need not ever beyoung. 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 wasplanted. New buildings were constructed and the supplies that werestored in them were spread out thin, for easy inspection.
The pups survived and within a year shot up to maturity. After propertraining, they were released to the fields where they joined the olderdogs. 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 forelectrical insulation. There was no protection except to keep thepower on at all times. Even then there were unwelcome interruptionsuntil the short was located and the charred carcass was removed.Vehicles were kept tightly closed or parked only in verminproofbuildings. While the plague didn't increase in numbers, it couldn't beeliminated, either.
There was a flurry of tigers, but they were larger animals and werepromptly shot down. They prowled at night, so the colonists wereassigned to guard the settlement around the clock. Where lights failedto reach, the infra-red 'scope did. As fast as they came, the tigersdied. Except for the first one, not a single dog was lost.
The tigers changed, though not in form. Externally, they were all bigand powerful killers. But as the slaughter went on, Marin noticed oneastonishing fact--the internal organic structure became progressivelymore immature.
The last one that was brought to him for examination was theequivalent of a newly born cub. That tiny stomach was suited more forthe digestion of milk than meat. How it had furnished energy to drivethose great muscles was something of a miracle. But drive it had, fora murderous fifteen minutes before the animal was brought down. Nolives 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 civilizationor even that fragment of it represented by the colony was too much forthe creature, which Marin by now had come to think of as the"Omnimal." It had evolved out of a cataclysmic past, but it could notmeet the challenge of the harshest environment.
Or so it seemed.
* * * * *
Three months before the next colonists were due, a new animal wasdetected. Food was missing from the fields. It was not another tiger:they were carnivorous. Nor rats, for vines were stripped in a mannerthat no rodent could manage.
The food was not important. The colony had enough in storage. But ifthe new animal signaled another plague, it was necessary to know howto meet it. The sooner they knew what the animal was, the betterdefense they could set up against it.
Dogs were useless. The animal roamed the field they were loose in, andthey did not attack nor even seem to know it was there.
The colonists were called upon for guard duty again, but it evadedthem. They patrolled for a week and they still did not catch sight ofit.
Hafner called them in and rigged up an alarm system in the field mostfrequented by the animal. It detected that, too, and moved its sphereof operations to a field in which the alarm system had not beeninstalled.
Hafner conferred with the engineer, who devised an alarm that wouldreact to body radiation. It was buried in the original field and theold 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 theanimal. They circled around and approached the field from the rear.The men in the camp had been alerted. If they needed help, it wasready.
They crept silently through the underbrush. It was feeding in thefield, 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 ontheir quarry. The gun dropped in Hafner's hand. He clenched his teethand 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'tshoot. It's more dangerous than you know."
Hafner hesitated and Marin went on. "The omnimal couldn't compete inthe changed environment and so it evolved mice. We stopped the miceand it countered with rats. We turned back the rat and it provided thetiger.
"The tiger was easiest of all for us and so it was apparently stoppedfor a while. But it didn't really stop. Another animal was beingformed, the one you see there. It took the omnimal two years to createit--how, I don't know. A million years were required to evolve it onEarth."
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 onEarth now, and on the other planets, down in the storage areas of ourbig cities, masquerading as rats. And we've never been able to rootout even our own terrestrial rats, so how can we exterminate theomnimal?"
"All the more reason to start now." Hafner's voice was flat.
Marin struck the rifle down. "Are their rats better than ours?" heasked wearily. "Will their pests win or ours be stronger? Or will thetwo make peace, unite and interbreed, make war on us? It's notimpossible; the omnimal could do it if interbreeding had a highsurvival factor.
"Don't you still see?
There is a progression. After the tiger, it bredthis. If this evolution fails, if we shoot it down, what will itcreate next? This creature I think we can compete with. _It's the oneafter this that I do not want to face._"
* * * * *
It heard them. It raised its head and looked around. Slowly it edgedaway and backed toward a nearby grove.
The biologist stood up and called softly. The creature scurried to thetrees and stopped just inside the shadows among them.
The two men laid down their rifles. Together they approached thegrove, hands spread open to show they carried no weapons.
It came out to meet them. Naked, it had had no time to learn aboutclothing. Neither did it have weapons. It plucked a large white flowerfrom the tree and extended this mutely as a sign of peace.
"I