There was no answer from the ground when breakout came and Calhoun drove the Med Ship to a favourable position for a call. He patiently repeated, over and over again, that the Med Ship Aesclipus Twenty notified its arrival and requested coordinates for landing. He added that its mass was fifty standard tons and that the purpose of its visit was a planetary health inspection.

But there was no reply. There should have been a crisp description of the direction from the planet's center at which, a certain time so many hours or minutes later, the force-fields of the grid would find it convenient to lock onto and lower the Med Ship. But the communicator remained silent.

"There is a landing-grid," said Calhoun, frowning, "and if they're using it to load fresh meat for Dara, from the herds I'm told about, it should be manned. But they don't seem to intend to answer. Maybe they think that if they pretend I'm not here I'll go away."

He reflected, and his frown deepened.

"If I didn't know what I know, I might. So if I land on emergency rockets the blueskins down below may decide that I come from Weald. And in that case it would be reasonable to blast me before I could land and unload some fighting men. On the other hand, no ship from Weald would conceivably land without impassioned assurance that it was safe. It would drop bombs." He turned to the girl. "How many Darians down below?"

She shook her head.

"You don't know," said Calhoun, "or won't tell, yet. But they ought to be told about the arrival of that ship at Weald, and what Weald thinks about it! My guess is that you came to tell them. It isn't likely that Dara gets news directly from Weald. Where were you put ashore from Dara, when you set out to be a spy?"

Her lips parted to speak, but she compressed them tightly. She shook her head again.

"It must have been plenty far away," said Calhoun restlessly. "Your people would have built a ship, and made fine forged papers for it, and they'd travel so far from this part of space that when they landed nobody would think of Dara. They'd use make-up to cover the blue spots, but maybe it was so far away that blueskins had never been heard of!"

Her face looked pinched, but she did not reply.

"Then they'd land half a dozen of you, with a supply of make-up for the blue patches. And you'd separate, and take ships that went various roundabout ways, and arrive on Weald one by one, to see what could be done there to—" He stopped. "When did you find out positively that there wasn't any plague any more?"

She began to grow pale.

"I'm not a mind reader," said Calhoun. "But it adds up. You're from Dara. You've been on Weald. It's practically certain that there are other ... agents, if you like that word better, on Weald. And there hasn't been a plague on Weald so you people aren't carriers of it. But you knew it in advance, I think. How'd you learn? Did a ship in some sort of trouble land there, on Dara?"

"Y—yes," said the girl. "We wouldn't let it go again. But the people didn't catch—they didn't die. They lived—"

She stopped short.

"It's not fair to trap me!" she cried passionately. "It's not fair!"

"I'll stop," said Calhoun.

He turned to the control board. The Med Ship was only planetary diameters from Orede, now, and the electron telescope showed shining stars in leisurely motion across its screen. Then a huge, gibbous shining shape appeared, and there were irregular patches of that muddy color which is seabottom, and varicolored areas which were plains and forests. Also there were mountains. Calhoun steadied the image, and squinted at it.

"The mine," he observed, "was found by members of a hunting party, killing wild cattle for sport."

Even a small planet has many millions of square miles of surface, and a single human installation on a whole world will not be easy to find by random search. But there were clues to this one. Men hunting for sport would not choose a tropic nor an arctic climate to hunt in. So if they found a mineral deposit, it would have been in a temperate zone.

Cattle would not be found deep in a mountainous terrain. The mine would not be on a prairie. The settlement on Orede, then, would be near the edge of mountains, not far from a prairie such as wild cattle would frequent, and it would be in a temperate climate.

Forested areas could be ruled out. And there would be a landing-grid. Handling only one ship at a time, it might be a very small grid. It could be only hundreds of yards across and less than half a mile high. But its shadow would be distinctive.

Calhoun searched among low mountains near unforested prairie in a temperate zone. He found a speck. He enlarged it manyfold. It was the mine on Orede. There were heaps of tailings. There was something which cast a long, lacy shadow: the landing-grid.

"But they don't answer our call," observed Calhoun, "so we go down unwelcomed."

He inverted the Med Ship and the emergency rockets boomed. The ship plunged planetward.

A long time later it was deep in the planet's atmosphere. The noise of its rockets had become thunderous, with air to carry and to reinforce the sound.

"Hold on to something, Murgatroyd," commanded Calhoun. "We may have to dodge some ack."

But nothing came up from below. The Med Ship again inverted itself, and its rockets pointed toward the planet and poured out pencil-thin, blue-white, high-velocity flames. It checked slightly, but continued to descend. It was not directly above the grid.

It swept downward until almost level with the peaks of the mountains in which the mine lay. It tilted again, and swept onward over the mountaintops, and then tilted once more and went racing up the valley in which the landing-grid was plainly visible. Calhoun swung it on an erratic course, lest there be opposition.

But there was no sign. Then the rockets bellowed, and the ship slowed its forward motion, hovered momentarily, and settled to solidity outside the framework of the grid. The grid was small, as Calhoun reasoned. But it reached interminably toward the sky.

The rockets cut off. Slender as the flames had been, they'd melted and bored thin drill-holes deep into the soil. Molten rock boiled and bubbled down below. But there seemed no other sound. There was no other motion. There was absolute stillness all around. But when Calhoun switched on the outside microphones a faint, sweet melange of high-pitched chirpings came from tiny creatures hidden under the vegetation of the mountainsides.

Calhoun put a blaster in his pocket and stood up.

"We'll see what it looks like outside," he said with a certain grimness. "I don't quite believe what the vision screens show."

Minutes later he stepped down to the ground from the Med Ship's exit port. The ship had landed perhaps a hundred feet from what once had been a wooden building. In it, ore from the mines was concentrated and the useless tailings carried away by a conveyer belt to make a monstrous pile of broken stone. But there was no longer a building.

Next to it there had been a structure containing an ore-crusher. The massive machinery could still be seen, but the structure was in fragments. Next to that, again, had been the shaft-head shelters of the mine. They also were shattered practically to matchsticks.

The look of the ground about the building sites was simply and purely impossible. It was a mass of hoofprints. Cattle by thousands and tens of thousands had trampled everything. Cattle had burst in the wooden sides of the buildings. Cattle had piled themselves up against the beams upholding roofs until the buildings collapsed.

Then cattle had gone plunging over the wrecked buildings until there was nothing left but indescribable chaos. Many, many cattle had died in the crush. There were heaps of dead beasts about the metal girders which were the foundation of the landing-grid. The air was tainted by the smell of carrion.

The settlement had been destroyed, positively by stampeded cattle in tens or hundreds of thousands charging blindly through and over and upon it. Senselessly, they'd trampled each other to horrible shapelessness. The mine shaft was not choked, because enormously strong timbers had fallen across and blocked it. But everything else was pure destruction.

Calhoun said evenly, "Clever! Very clever! You can't blame men when beasts stampede. We should accept the evidence that some monstrous herd, making its way through a mountain pass, somehow went crazy and bolted for the plains. This settlement got in the way and it was too bad for the settlement! Everything's explained, except the ship that went to Weald.

"A cattle stampede, yes. Anybody can believe that! But there was a man stampede. Men stampeded into the ship as blindly as the cattle trampled down this little town. The ship stampeded off into space as insanely as the cattle. But a stampede of men and cattle, in the same place? That's a little too much!"

"But what—"

"How," asked Calhoun directly, "do you intend to get in touch with your friends here?"

"I—I don't know," she said, distressed. "But if the ship stays here, they're bound to come and see why. Won't they? Or will they?"

"If they're sane, they won't," said Calhoun. "The one undesirable thing, here, would be human footprints on top of cattle tracks. If your friends are a meat-getting party from Dara, as I believe, they should cover up their tracks, get off-planet as fast as possible, and pray that no signs of their former presence are ever discovered. That would be their best first move, certainly!"

"What should I do?" she asked helplessly.

"I'm far from sure. At a guess, and for the moment, probably nothing. I'll work something out. I've got the devil of a job before me, though. I can't spend but so much time here."

"You can leave me here...."

He grunted and turned away. It was naturally unthinkable that he should leave another human being on a supposedly uninhabited planet, with the knowledge that it might actually be uninhabited, and the future knowledge that any visitors would have the strongest of possible reasons to hide themselves away.

He believed that there were Darians here, and the girl in the Med ship, so he also believed, was also a Darian. But any who might be hiding had so much to lose if they were discovered that they might be hundreds or even thousands of miles from anywhere a space ship would normally land—if they hadn't fled after the incident of the spaceship's departure with its load of doomed passengers.

Considered detachedly, the odds were that there was again a food shortage on Dara; that blueskins, in desperation, had raided or were raiding or would raid the cattle herds of Orede for food to carry back to their home planet; that somehow the miners on Orede had found that they had blueskin neighbors, and died of the consequences of their terror. It was a risky guess to make on such evidence as Calhoun considered he had, but no other guess was possible.

If his guess were right, he was under some obligation to do exactly what he believed the girl considered her mission—to warn all blueskins that Weald would presently try to find them on Orede, when all hell must break loose upon Dara for punishment. But if there were men here, he couldn't leave a written warning for them in default of friendly contact.

They might not find it, and a search party of Wealdians might. All he could possibly do was try to make contact and give warning by such means as would leave no evidence behind that he'd done so. Weald would consider a warning sure proof of blueskin guilt.

It was not satisfactory to be limited to broadcasts which might or might not be picked up, and were unlikely to be acknowledged. But he settled down with the communicator to make the attempt.

He called first on a GC wave length and form. It was unlikely that blueskins would use general communication bands to keep in touch with each other, but it had to be tried. He broadcast, tuned as broadly as possible, and went up and down the GC spectrum, repeating his warning painstakingly and listening without hope for a reply.

He did find one spot on the dial where there was re-radiation of his message, as if from a tuned receiver. But he could not get a fix on it: nobody might be listening. He exhausted the normal communication pattern. Then he broadcast on old-fashioned amplitude modulation which a modern communicator would not pick up at all, and which therefore might be used by men in hiding.

He worked for a long time. Then he shrugged and gave it up. He'd repeated to absolute tedium the facts that any Darians—blueskins—on Orede ought to know. There'd been no answer. And it was all too likely that if he'd been received, that those who heard him took his message for a trick to discover if there were any hearers.

He clicked off at last and stood up, shaking his head. Suddenly the Med Ship seemed empty. Then he saw Murgatroyd staring vexedly at the exit port. The inner door of that small airlock was closed. The telltale light said the outer door was not locked. Someone had gone out quietly. The girl. Of course.

Calhoun said angrily, "How long ago, Murgatroyd?"

"Chee!" said Murgatroyd indignantly.

It wasn't an answer, but it showed that Murgatroyd was vexed that he'd been left behind. He and the girl were close friends, now. If she'd left Murgatroyd in the ship when he wanted to go with her, then she wasn't coming back.

Calhoun swore. He made certain she was not in the ship. He flipped the outside-speaker switch and said curtly into the microphone, "Coffee! Murgatroyd and I are having coffee. Will you come back, please?"

He repeated the call, and repeated it again. Multiplied as his voice was by the speakers, she should hear him within a mile. She did not appear. He went to a small and inconspicuous closet and armed himself. A Med Ship man was not ever expected to fight, but there were blast-rifles available for extreme emergency.

When he'd slung a power-pack over his shoulder and reached the airlock, there was still no sign of his late stowaway. He stood in the airlock door for long minutes, staring angrily about. Almost certainly she wouldn't be looking in the mountains for men of Dara come here for cattle. He used a pair of binoculars, first at low-magnification to search as wide an area down-valley as possible, and then at highest power to search the most likely routes.

He found a small, bobbing speck beyond a faraway hill crest. It was her head. It went down below the hilltop.

He snapped a command to Murgatroyd, and when the tormal was on the ground outside, he locked the port with that combination that nobody but a Med Ship man was at all likely to discover or use.

"She's an idiot!" he told Murgatroyd sourly. "Come along! We've got to be idiots too!"

He set out in pursuit.

There was blue sky overhead, as was inevitable on any oxygen-atmosphere planet of a Sol-type yellow sun. There were mountains, as is universal in planets whose surface rises and falls and folds and bends from the effects of weather or vulcanism. There were plants, as has come about wherever microorganisms have broken down rock to a state where it can nourish vegetation. And naturally there were animals.

There were even trees of severely practical design, and underbrush and ground-cover equivalent to grass. There was, in short, a perfectly predictable ecological system on Orede. The organic molecules involved in life here would be made up of the same elements in the same combinations as elsewhere where the same conditions of temperature and moisture and sunshine obtained.

It was a distinctly Earthlike world, as it could not help but be, and it was reasonable for cattle to thrive and increase here. Only men's minds kept it from being a place where humans would thrive, too.

But only Calhoun would have considered the splintered settlement a proof of that last.

The girl had a long start. Twice Calhoun came to places where she could have chosen either of two ways onward. Each time he had to determine which she'd followed. That cost time. Then the mountains abruptly ended and a vast undulating plain stretched away to the horizon. There were at least two large masses and many smaller clumps of what could only be animals gathered together. Cattle.

But here the girl was plainly in view. Calhoun increased his stride. He began to gain on her. She did not look behind.

Murgatroyd said "Chee!" in a complaining tone.

"I should have left you behind," agreed Calhoun dourly, "but there was and is a chance I won't get back. You'll have to keep on hiking."

He plodded on. His memory of the terrain around the mining settlement told him that there was no definite destination in the girl's mind. But she was in no such despair as to want deliberately to be lost. She'd guessed, Calhoun believed, that if there were Darians on the planet, they'd keep the landing-grid under observation.

If they saw her leave that area and could see that she was alone, they should intercept her to find out the meaning of the Med Ship's landing. Then she could identify herself as one of them and give them the terribly necessary warning of Weald's suspicions.

"But," said Calhoun sourly, "if she's right, they'll have seen me marching after her now, which spoils her scheme. And I'd like to help it, but the way she's going is too dangerous!"

He went down into one of the hollows of the uneven plain. He saw a clump of a dozen or so cattle a little distance away. The bull looked up and snorted. The cows regarded him truculently. Their air was not one of bovine tranquility.

He was up the farther hillside and out of sight before the bull worked himself up to a charge. Then Calhoun suddenly remembered one of the items in the data about cattle he'd looked into just the other day. He felt himself grow pale.

"Murgatroyd!" he said sharply. "We've got to catch up! Fast! Stay with me if you can, but—" he was jog-trotting as he spoke—"even if you get lost I have to hurry!"

He ran fifty paces and walked fifty paces. He ran fifty and walked fifty. He saw her, atop a rolling of the ground. She came to a full stop. He ran. He saw her turn to retrace her steps. He flung off the safety of the blast-rifle and let off a roaring blast at the ground for her to hear.

Suddenly she was fleeing desperately, toward him. He plunged on. She vanished down into a hollow. Horns appeared over the hillcrest she'd just left. Cattle appeared. Four, a dozen fifteen, twenty! They moved ominously in her wake.

He saw her again, running frantically over another upward swell of the prairie. He let off another blast to guide her. He ran on at top speed with Murgatroyd trailing anxiously behind. From time to time Murgatroyd called "Chee-chee-chee!" in frightened pleading not to be abandoned.

More cattle appeared against the horizon. Fifty or a hundred. They came after the first clump. The first group of a bull and his harem were moving faster, now. The girl fled from them, but it is the instinct of beef-cattle on the open range—Calhoun had learned it only two days before—to charge any human they find on foot. A mounted man to their dim minds is a creature to be tolerated or fled from, but a human on foot is to be crushed and stamped and gored.

Those in the lead were definitely charging now, with heads bent low. The bull charged furiously with shut eyes, as bulls do, but the cows, many times more deadly, charged with their eyes wide open and wickedly alert, and with a lumbering speed much greater than the girl could manage.

She came up over the last rise, chalky-white and gasping, her hair flying, in the last extremity of terror. The nearest of the pursuing cattle were within ten yards when Calhoun fired from twenty yards beyond. One creature bellowed as the blast-bolt struck.

It went down and others crashed into it and swept over it, and more came on. The girl saw Calhoun now, and ran toward him, panting. He knelt very deliberately and began to check the charge by shooting the leading animals.

He did not succeed. There were more cattle following the first, and more and more behind them. It appeared that all the cattle on the plain joined in the blind and senseless charge. The thudding of hoofs became a mutter and then a rumble and then a growl.

Plunging, clumsy figures rushed past on either side. But horns and heads heaved up over the mound of animals Calhoun had shot. He shot them too. More and more cattle came pounding past the rampart of his victims, but always, it seemed, some elected to climb the heap of their dead and dying fellows, and Calhoun shot and shot....

But he split the herd. The foremost animals had been charging a sighted human enemy. Others had followed because it is the instinct of cattle to join their running fellows in whatever crazed urgency they feel. There was a dense, pounding, wailing, grunting, puffing, raising thick and impenetrable clouds of dust which hid everything but galloping beasts going past on either side.

It lasted for minutes. Then the thunder of hoofs diminished. It ended abruptly, and Calhoun and the girl were left alone with the gruesome pile of animals which had divided the charging herd into two parts. They could see the rears of innumerable running animals, stupidly continuing the charge, hardly different, now, from a stampede, whose original objective none now remembered.

Calhoun thoughtfully touched the barrel of his blast-rifle and winced at its scorching heat.

"I just realized," he said coldly, "that I don't know your name. What is it?"

"Maril," said the girl. She swallowed. "Th—thank you."

"Maril," said Calhoun, "you are an idiot! It was half-witted at best to go off by yourself! You could have been lost! You could have cost me days of hunting for you, days badly needed for more important matters!"

He stopped and took breath. "You may have spoiled what little chance I've got to do something about the plans Weald's already making! You have just acted with the most concentrated folly, and the most magnificent imbecility that you or anybody else could manage!"

He said more bitterly still, "And I had to leave Murgatroyd behind to get to you in time! He was right in the path of that charge!"

He turned away from her and said dourly, "All right! Come on back to the ship. We'll go to Dara. We'd have to, anyhow. But Murgatroyd—"

Then he heard a very small sneeze. Out of a rolling wall of still-roiling dust, Murgatroyd appeared forlornly. He was dust-covered, and draggled, and his tail dropped, and he sneezed again. He moved as if he could barely put one paw before another, but at sight of Calhoun he sneezed yet again and said "Chee!" in a disconsolate voice. Then he sat down and waited for Calhoun to come and pick him up.

When Calhoun did so, Murgatroyd clung to him pathetically and said "Chee-chee!" and again "Chee-chee!" with the intonation of one telling of incredible horrors and disasters endured. And as a matter of fact the escape of a small animal like Murgatroyd was remarkable. He'd escaped the trampling hoofs of at least hundreds of charging animals. Luck must have played a great part in it, but an hysterical agility in dodging must have been required, too.

Calhoun headed back for the valley where the settlement had been, and the Med Ship was. Murgatroyd clung to his neck. The girl Maril followed discouragedly. She was at that age when girls—and men of corresponding type—can grow most passionately devoted to ideals or causes in default of a promising personal romance. When concerned with such causes they become splendidly confident that whatever they decide to do is sensible if only it is dramatic. But Maril was shaken, now.

Calhoun did not speak to her again. He led the way. A mile back toward the mountains, they began to see stragglers from the now-vanished herd. A little farther, those stragglers began to notice them. It would have been a matter of no moment if they'd been domesticated dairy cattle, but these were range cattle gone wild. Twice, Calhoun had to use his blast-rifle to discourage incipient charges by irritated bulls or even more irritated cows. Those with calves darkly suspected Calhoun of designs upon their offspring.

It was a relief to enter the valley again. But it was two miles more to the landing-grid with the Med Ship beside it and the reek of carrion in the air.

They were perhaps two hundred feet from the ship when a blast-rifle crashed and its bolt whined past Calhoun so close that he felt the monstrous heat. There had been no challenge. There was no warning. There was simply a shot which came horribly close to ending Calhoun's career in a completely arbitrary fashion.

---