Twenty minutes later, Yerdeth Pell looked up from the data book facsimiles and scanned Dodeth's face with appraising eyes.

"Very cute," he said at last, with a slight chuckle. "Now, what I want to know is: is someone playing a joke on you, or are you playing a joke on me?"

Dodeth's eyelids slid upwards in a fast blink of surprise. "What do you mean?"

"Why, these bathygraphs." Yerdeth rapped the bathygraphs with a wrinkled, horny hand. He was a good deal older than Dodeth, and his voice had a tendency to rasp a little when the frequency went above twenty thousand cycles. "They're very good, of course. Very good. The models have very fine detail to them. The eyes, especially are good; they look as if they really ought to be built that way." He smiled and looked up at Dodeth.

Dodeth resisted an urge to ripple a stomp. "Well?" he said impatiently.

"Well, they can't be real, you know," Yerdeth replied mildly.

"Why not?"

"Oh, come, now, Dodeth. What did it evolve from? An animal doesn't just spring out of nowhere, you know."

"New species are discovered occasionally," Dodeth said. "And there are plenty of mutants and just plain freaks."

"Certainly, certainly. But you don't hatch a snith out of a hurkle egg. Where are your intermediate stages?"

"Is it possible that we might have missed the intermediate stage?"

"I said 'stages'. Plural. Pick any known animal—any one—and tell me how many genetic changes would have to take place before you'd come up with an animal anything like this one." Again he tapped the bathygraph. "Take that eye, for instance. The lid goes down instead of up, but you notice that there's a smaller lid at the bottom that does go up, a little ways. The closest thing to an eye like that is on the hugl, which has eyelids on top that lower a little. But the hugl has eighteen segments; sixteen pairs of legs and two pairs of feeding claws. Besides, it's only the size of your thumb-joint. What kind of gene mutation would it take to change that into an animal like the one in this picture?

"And look at the size of the thing. If it weren't in that awkward vertical position, if it were stretched out on the ground, it'd be a long as a human. Look at the size of those legs!

"Or, take another thing. In order to walk on those two legs, the changes in skeletal and visceral structure would have to be tremendous."

"Couldn't we have missed the intermediate stages, then?" Dodeth asked stubbornly. "We've missed the intermediates before, I dare say."

"Perhaps we have," Yerdeth admitted, "but if you boys in the Ecological Corps have been on your toes for the past thousand years, we haven't missed many. And it would take at least that long for something like this to evolve from anything we know."

"Even under direct polar bombardment?"

"Even under direct polar bombardment. The radiation up here is strong enough to sterilize a race within a very few generations. And what would they eat? Not many plants survive there, you know.

"Oh, I don't say it's flatly impossible, you understand. If a female of some animal or other, carrying a freshly-fertilized zygote, and her species happened to have all the necessary potential characteristics, and a flood of ionizing radiation went through the zygote at exactly the right time, and it managed to hit just the right genes in just the right way ... well I'm sure you can see the odds against it are tremendous. I wouldn't even want to guess at the order of magnitude of the exponent. I'd have to put on a ten in order to give you the odds against it."

Dodeth didn't quite get that last statement, but he let it pass. "I am going to pull somebody's legs off, one by one, come next work period," he said coldly. "One ... by ... one."

He didn't, though. Rather than accuse Wygor, it would be better if Wygor were allowed to accuse himself. Dodeth merely wanted to wait for the opportunity to present itself. And then—ah, then there would be a roasting!

The opportunity came in the latter part of the next work period. Wygor, who had purportedly been up on the surface for another field trip, scuttled excitedly into Dodeth's office, wildly waving some bathygraph sheets.

"Dodeth, sir! Look! I came down as soon as I saw it! I've got the 'graphs right here! Horrible!"

Before Dodeth could say anything, Wygor had spread the sheets out fan-wise on his business bench. Dodeth looked at them and experienced a moment of horror himself before he realized that these were—these must be—doctored bathygraphs. Even so, he gave an involuntary gasp.

The first 'graphs had been taken from an aerial reconnaissance robot winging in low over the treetops. The others were taken from a higher altitude. They all showed the same carnage.

An area of several thousand square feet—tens of thousands!—had been cleared of trees! They had been ruthlessly cut down and stacked. Bushes and vines had gone with them, and the grass had been crushed and plowed up by the dragging of the great fallen trees. And there were obvious signs that the work was still going on. In the close-ups, he could see the bipedal beasts wielding cutting instruments.

Dodeth forced himself to calmness and glared at the bathygraphs. Fry it, they had to be fakes. A new species might appear only once in a hundred years, but according to Yerdeth, this couldn't possibly be a new species. What was Wygor's purpose in lying, though? Why should he falsify data? And it must be he; he had said that he had seen the beasts himself. Well, Dodeth would have to find out.

"Tool users, eh?" he said, amazed at the calmness of his voice. Such animals weren't unusual. The sniths used tools for digging and even for fighting each other. And the hurkles dammed up small streams with logs to increase their marshland. It wasn't immediately apparent what these beasts were up to, but it was far too destructive to allow it to go on.

But, fry it all, it couldn't be going on!

There were only two alternatives. Either Wygor was a liar or Yerdeth didn't know what he was talking about. And there was only one way of finding out which was which.

"Ardan! Get my equipment ready! We're going on a field trip! Wygor, you get the rest of the expedition ready; you and I are going up to see what all this is about." He jabbed at the communicator button. "Fry it! Why should this have to happen in my sector? Hello! Give me an inter-city connection. I want to talk to Baythim Venns, co-ordinator of Ecological Control, in Faisalla."

He looked up at Wygor. "Scatter off, fry it! I want to—Oh, hello, Baythim, sir. Dodeth. Have you had any reports on a new species—a bipedal one? What? No, sir; I'm not kidding. One of my men has brought in 'graphs of the thing. Frankly, I'm inclined to think it's a hoax of some kind, but I'd like to ask you to check to see if it's been reported in any of the other areas. We're located a little out of the way here, and I thought perhaps some of the stations farther north or south had seen it. Yes. That's right: two locomotive limbs, two handling limbs. Big as a human, and they hold their bodies perpendicular to the ground. Yes, sir, I know it sounds silly, and I'm going out to check the story now, but you ought to see these bathygraphs. If it's a hoax, there's an expert behind it. Very well, sir; I'll wait."

Dodeth scowled. Baythim had sounded as if he, Dodeth, had lost his senses.

Maybe I have, he thought. Maybe I'll start running around mindlessly and get shot down by some patrol robot who thinks I'm a snith.

Maybe he should have investigated first and then called, when he was sure, one way or another. Maybe he should have told Baythim he was certain it was a hoax, instead of hedging his bets. Maybe a lot of things, but it was too—

"Hello? Yes, sir. None, eh? Yes, sir. Yes, sir; I'll give you a call as soon as I've checked. Yes, sir. Thank you, sir."

Dodeth felt like an absolute fool. Individually and collectively, he consigned to the frying pan Baythim, Wygor, Yerdeth, the new beast—if it existed—and finally, himself.

By the time he had finished his all-encompassing curse, his two dozen pistoning legs had nearly brought him to the equipment room, where Ardan and Wygor were waiting.

Four hours and more of steady traveling did very little to sweeten Dodeth Pell's temper. The armored car was uncomfortable, and the silence within it was even more uncomfortable. He did not at all feel like making small talk with Wygor, and he had nothing as yet to say to Ardan or the patrol robots who were rolling along with the armored car.

One thing he had to admit: Wygor certainly didn't act like a man who was being carried to his own doom—which he certainly was if this was hoax. Wygor would lose all position and be reduced to living off his civil insurance. He would be pitied by all and respected by none.

But he didn't look as though that worried him at all.

Dodeth contented himself with looking at the scenery. The car was not yet into the forest country; this was all rolling grassland. Off to one side, a small herd of grazing grancos lifted their graceful heads to watch the passage of the expedition, then lowered them again to feed. A fanged zitibanth, disturbed in the act of stalking the grancos, stiffened all his legs and froze for a moment, looking balefully at the car and the robots, then went on about his business.

When they came to the forest, the going became somewhat harder. Centuries ago, those who had tried to build cities on the surface had also built paved strips to make travel by car easier and smoother, and Dodeth almost wished there were one leading to the target area.

Fry it, he hated traveling! Especially in a lurching armored car. He wished he were bored enough or tired enough to go to sleep.

At last—at long last—Wygor ordered the car to stop. "We're within two miles of the clearing, sir," he told Dodeth.

"All right," Dodeth said morosely. "We'll go the rest of the way on foot. I don't want to startle them at this stage of the game, so keep it quiet and stay hidden. Tell the patrol robots to spread out, and tell them I want all the movie shots we can get. I want all the Keepers to see these things in action. Got that? Then let's get moving."

They crept forward through the forest, Dodeth and Ardan taking the right, while Wygor and his own robot, Arsam, stayed a few yards away to the left. They were all expert woodsmen—Dodeth and Wygor by training and experience, and the robots by indoctrination.

Even so, Dodeth never felt completely comfortable above ground, with nothing over his head but the clouded sky.

The team had purposely chosen to approach from a small rise, where they could look down on the clearing without being seen. And when they reached the incline that led up to the ridge, one of the armed patrol robots who had been in the lead took a look over the ridge and then scuttled back to Dodeth. "They're there, sir."

"What are they doing?" Dodeth asked, scarcely daring to believe.

"Feeding, I believe, sir. They aren't cutting down any trees now; they're just sitting on one of the logs, feeding themselves with their handling limbs."

"How many are there?"

"Twenty, sir."

"I'll take a look." He scrambled up the ridge and peeked over.

And there they were, less than a quarter of a mile away.

Dazedly, Dodeth took a pair of field glasses from Ardan and focused them on the group.

Oh, they were real, all right. No doubt of that. None whatever. Mechanically, he counted them. Twenty. Most of them were feeding, but four of them seemed to be standing a little apart from the others, watching the forest, acting as lookouts.

Typical herd action, Dodeth thought.

He wished Yerdeth were here; he'd show that fool what good his ten-to-the-billionth odds were.

And yet, in another way, Dodeth had the feeling that his parabrother was right. How could the life of the World have suddenly evolved such creatures? For they looked even more impossible when seen in the flesh.

Their locomotive limbs ended in lumpy protuberances that showed no sign of toes, and they were covered all over with a dull gray hide, except for the hands at the ends of their handling limbs and the necks and the faces of their oddly-shaped heads, where the skin ranged in color from a pinkish an to a definitive brown, depending on the individual. There was no hair anywhere on their bodies except on the top and back of their heads. No, wait—there were two long tufts above each eye. They—

"Do you see what they're eating?" Wygor's voice whispered.

Dodeth hadn't. He'd been too busy looking at the things themselves. But when he did notice, he made a noise like a throttled "Geep!"

Hurkles!

There were few enough of the animals—only a few small population was needed to keep the Balance, but they were important. And the swamps were drying up, and the quiggies were moving in on them, and now—

Dodeth made a hasty count. Twenty! By the Universal Motivator, these predators had eaten a hurkle apiece!

Overhead, the Yellow Sun, a distant dot of intensely bright light, shed its wan glow over the ghastly scene. Dodeth wished the Moon were out; its much brighter light would have shown him more detail.

But he could see well enough to count the gnawed skeletons of the little, harmless hurkles. Even the Moon, which wouldn't bring morning for another fifteen work periods yet, couldn't have made it any plainer that these beasts were deadly dangerous to the Balance.

"How often do they eat?" he asked in a strained voice.

It was Wygor's robot, Arsam, who answered. "About three times every work period. They sleep then. Their metabolic cycle seems to be timed about the same as yours, sir."

"Gaw!" said Dodeth. "Sixty hurkles per sleep period! Why, they'll have the whole hurkle population eaten before long! Wygor! As soon as we can get shots of all this, we're going back! There's not a moment to lose! This is the most deadly dangerous thing that has ever happened to the World!"

"Fry me, yes," Wygor said in an awed voice. "Three hurkles in one period."

"Allow me to correct you, sir," said the patrol robot. "They do not eat that many hurkles. They eat other things besides."

"Like what, for instance?" Dodeth asked in a choked voice.

The robot told him, and Dodeth groaned. "Omnivores! That's even worse! Ardan, pass the word to the scouts to get their pictures and meet at that tree down there behind us in ten minutes. We've got to get back to the city!"

Dodeth Pell laid his palms flat on the speaker's bench and looked around at the assembled Keepers of the Balance, wise and prudence thinkers, who had spent lifetimes in ecological service and had shown their capabilities many times over.

"And that's the situation, sirs," he said, after a significant pause. "The moving and still bathygraphs, the data sheets, and the samplings of the area all tell the same story. I do not feel that I, alone, can make the decision. Emotionally, I must admit, I am tempted to destroy all twenty of the monsters. Intellectually, I realize that we should attempt to capture at least one family group—if we can discover what constitutes a family group in this species. Unfortunately, we cannot tell the sexes apart by visual inspection; the sex organs themselves must be hidden in the folds of that gray hide. And this is evidently not their breeding season, for we have seen no sign of sexual activity.

"We have very little time, sirs, it seems to me. The damage they have already done will take years to repair, and the danger of upsetting the Balance irreparably grows exponentially greater with every passing work period.

"Sirs, I ask your advice and your decision."

There was a murmur of approval for his presentation as he came down from the speakers bench. Then the Keepers went into their respective committee meetings so discuss the various problems of detail that had arisen out of the one great problem.

Dodeth went into an anteroom and tried to relax and get a little sleep—though he doubted he'd get any. His nerves were too much on edge.

Ardan woke him gently. "Your breakfast, sir."

Dodeth blinked and jerked his head up. "Oh. Uhum. Ardan! Have the Keepers reached any decision yet?"

"No, sir; not yet. The data are still coming in."

It was three more work periods before the Keepers called Dodeth Pell before them again. Dodeth could almost read the decision on their faces—there was both sadness and determination there.

"It was an uncomfortable decision, Dodeth Pell," said the Eldest Keeper without preliminary, "but a necessary one. We can find no place in the Ecological Balance for this species. We have already ordered a patrol column of two hundred fully-armed pesticide robots to destroy the animals. Two are to be captured alive, if possible, but, if not, the bodies will be brought to the biological laboratories for study. Within a few hours, the species will be nearly or completely extinct.

"By the way, you may tell your assistant, Wygor, that the animal will go down in the files as wygorex. A unique distinction for him, in many ways, but not, I fear, a happy one."

Dodeth nodded silently. Now that the decision had been made, he felt rather bad about it. Something in him rebelled at the thought of a species becoming extinct, no matter how great the need. He wondered if it would be possible for the biologists and the geneticists to trace the evolution of the animal. He hoped so. At least they deserved that much.

Dodeth Pell delayed returning to his own city; he wanted to wait until the final results had been brought in before he returned to his duties. The delay turned out to be a little longer than he expected—much longer, in fact. The communicator in his temporary room buzzed, and when he answered, Wygor's voice came to him, a rush of excited words that didn't make any sense at all at first. And when it did make sense he didn't believe it.

"What?" he squealed. "What?"

"I said," Wygor repeated, "that the report has come back from the pesticide column! They've found no trace of any such animal as we've described! They're nowhere to be found, in or near the clearing!"

"I think," said Dodeth very calmly, "that I'll take a little trip over to the Brightside and take up permanent residence there. It's going to be pretty hot for me around here before long."

And he cut the connection without waiting for Wygor's answer.

The armored car jounced across the grassland at high speed. Behind it, two more cars followed, each taking care not to run exactly in the tracks of the one ahead, so that there would be as little damage as possible done to the grass.

In the lead car, Dodeth Pell watched the forest loom nearer, wondering what sort of madness he would find there this time. Beside him, the Eldest Keeper dozed gently, in the way that only the very young or the very old can doze. It was just as well; Dodeth didn't feel much like talking.

This time, as they approached the clearing, he didn't bother to tell the car to stop two miles away. If the animals were gone, there was no point in being cautious. All through the wooded area, he could see occasional members of the pesticide robots. He told the car to stop at the base of the little rise that he used before as a vantage point. Then, without further preliminaries, he got out of the car and marched up the slope to take a look at the clearing. Overhead, the burning spark of the Yellow Sun cast its pale radiance over the landscape.

At the ridge, he stopped suddenly and ducked his head. Then he grabbed his field glasses and took a good look.

The animals had built themselves a few crude-looking shelters out of the logs, but he hardly noticed that.

There were four of the animals, in plain sight, standing guard!

The others were obviously inside the rude huts, asleep!

Great galloping fungus blight! Was he out of his mind? What was going on around here? Couldn't the robots see the beasts?

"That's very odd," said the voice of the Eldest Keeper in puzzled tones. "I thought the robots said they'd gone away. Lend me your field glasses."