"Very much of physical science is merely the comprehension of long-observed facts. In human conduct, there is a long tradition of observation, but a very brief record of comprehension. For example, human life in contact with other human lives follows the rules of other ecological systems. All too often, however, a man may imagine that an ecological system is composed only of things, whereas such a system operates through the actions of things. It is not possible for any part of an ecological complex to act upon the other parts without being acted upon, in its turn. So that it is singularly stupid—and singularly common—for an individual to consider human society as passive and unreactive, so that he may do what he pleases without a reaction as energetic as his action, and as well-directed. Moreover, probability—."Probability and Human ConductFitzgerald
"Very much of physical science is merely the comprehension of long-observed facts. In human conduct, there is a long tradition of observation, but a very brief record of comprehension. For example, human life in contact with other human lives follows the rules of other ecological systems. All too often, however, a man may imagine that an ecological system is composed only of things, whereas such a system operates through the actions of things. It is not possible for any part of an ecological complex to act upon the other parts without being acted upon, in its turn. So that it is singularly stupid—and singularly common—for an individual to consider human society as passive and unreactive, so that he may do what he pleases without a reaction as energetic as his action, and as well-directed. Moreover, probability—."
Probability and Human ConductFitzgerald
An hour after sunrise Calhoun's shoulder-pack was empty of food. The refugees arose, and they were weak and ravenous. Their respiration had slowed to normal. Their pulses no longer pounded. Their eyes were no longer dull, but very bright. But they were in advanced states of malnutrition, and only now were aware of it. Their brains were again receiving adequate oxygen and their metabolism was at a normal level—and they knew that they were starving.
Calhoun served as cook. He trudged to the spring that Helen described and brought back water. While they sucked on sweet tablets from his rations and watched with hungry eyes, he made soup from the dehydrated rations he'd carried for Murgatroyd and himself. He gave it to them as the first thing their stomachs were likely to digest.
He watched as they fed themselves. The elderly man and woman consumed it delicately, looking at each other. The man with the broad dark beard ate with enormous self-restraint. Helen fed the weakest oldest man, between spoonfuls for herself, and Kim Walpole ate slowly, brooding.
Calhoun drew him aside.
"During the night," he said, "I got another lot of serum ready. I'm leaving it with you, with an injector. You'll find other refugees. I gave you massive doses. You'd better be stingy. Try half-CC shots."
"What about you?" demanded Kim.
Calhoun shrugged.
"You'd be surprised how much authority I have—when I can make it stick," he said dryly. "As a Med Ship man I've authority to take complete charge of any health emergency. You people have a hitherto unknown plague here. That's one emergency. The present inhabitants of the city haven't got it. That's another. So since I have authority and reason to exercise it if I can, I'm going to the city to take a little action."
"You'll be killed," said Kim.
"Possibly," admitted Calhoun. "But the number of chance happenings that could favor me is very much greater than the number of breaks that could favor the invaders. And there's the matter of colonists. Prospective colonists. You're being hunted so hard that they must be about due. They've probably been immunized against this plague, but technically I shouldn't let them land on a plague-stricken planet."
Kim Walpole stared.
"You mean you'll try to stop them?"
"I shall try," said Calhoun, "to implement the authority vested in me by the Med Service for such cases as this. The rules about quarantine are rather strict."
"You'll be killed," said Kim, again.
Calhoun ignored the repeated prediction.
"That hunter found you," he observed, "because he knew that you'd have to drink. So he found a brook and followed it up, looking for signs of humans drinking from it. He found footprints about the spring. I found his footprints there, too. That's the trick you'll use to find other fugitives. But pass on the word not to leave tracks hereafter. For other advice, I advise you to get all the weapons you can. Modern ones, of course. You've got the blaster from the man I killed."
"I think," said Kim between his teeth, "that I'll get some more. If hunters from the city do track us to our drinking places, I'll know how to get more weapons!"
"Yes," agreed Calhoun, and added, "Murgatroyd made the antibodies that cured you. As a general rule, you can expect antibody production in your own bodies once an infection begins to be licked. In case of extreme emergency, each of you can probably supply antibodies for a fair number of other plague-victims. You might try serum from blisters you produce on your skin. Quite often antibodies turn up there. I don't guarantee it, but sometimes it works."
He paused. Kim Walpole said harshly:
"But you! Isn't there anything we can do for you?"
"I was going to ask you something," said Calhoun. He produced the telephoto films of the city as photographed from space. "There's a laboratory in the city—a biochemistry lab. Show me where to look for it."
Walpole gave explicit directions, pointing out the spot on the photo. Calhoun nodded. Then Kim said fiercely:
"But tell us something we can do! We'll be strong, presently! We'll have weapons! We'll track down-stream to where hunters leave their ground-cars and be equipped with them! We can help you!"
Calhoun nodded approvingly.
"Right. If you see the smoke of a good-sized fire in the city, and if you've got a fair number of fairly strong men with you, and if you've got ground-cars, you might investigate. But be cagey about it! Very cagey!"
"If you signal we'll come," said Kim Walpole grimly, "no matter how few we are!"
"Fine!" said Calhoun. He had no intention of calling on these weakened, starveling people for help.
He swung his depleted pack on his back again and slipped away from the glade. He made his way to the spring, which flowed clear and cool from unseen depths. He headed down the little brook which flowed away from it. Murgatroyd raced along its banks. He hated to get his paws wet. Presently, where the underbrush grew thickly close to the water's edge, Murgatroyd wailed. "Chee! Chee!" And Calhoun plucked him from the ground and set him on his shoulder. Murgatroyd clung blissfully there as Calhoun followed down the stream bed. He adored being carried.
Two miles down, there was another cultivated field. This one was set out to a gigantized root-crop, and Calhoun walked past shoulder-high bushes with four-inch blue-and-white flowers. He recognized the plants as of the familysolanaceae—belladona was still used in medicine—but he couldn't identify it until he dug up a root and found a potato. But the six-pound specimen he uncovered was still too young and green to be eaten. Murgatroyd refused to touch it.
Calhoun was ruefully considering the limitations of specialized training when he came to the end of the cultivated field. There was a highway. It was new, of course. City, fields, highways and all the appurtenances of civilized life had been built on this planet before the arrival of the colonists who were to inhabit it. It was extraordinary to see such preparations for a population not yet on hand. But Calhoun was much more interested in the ground-car he found waiting on the highway, hard by a tiny bridge under which the brook he followed flowed.
The key he'd taken from the hunter fitted. He got in and put Murgatroyd on the seat beside him.
"These invaders, Murgatroyd," he observed, "must be in a bad way. A newly-built city which was never occupied will be like an empty house. There's no amusement or loot to be found in prowling it. They were sent to take over the planet, and they've done it. But they've nothing to do now, except hunt refugees—until their colonists arrive. I suspect they're bored. We'll try to fix that!"
He set the ground-car in motion. Toward the city.
It was a full twenty miles, but he did not encounter a single other vehicle. Presently the city lay spread out before him. He stopped and surveyed the vast pile. It was a very beautiful city. Fifty generations of architects on many worlds had played with stone and steel, groping for the perfect combination of materials with design. This city was a product of their tradition. There were towers which glittered whitely, and low buildings which seemed to nestle on the vegetation-covered ground. There were soaring bridges, and gracefully curving highways, and park areas laid out and ready. There was no monotony anywhere.
The only exception to gracefulness was the sturdy landing grid itself, half a mile high and a mile across, which was a lace-work of massive steel girders with spider-thin lines of copper woven about in the complex curves the creation of its force-field required. Inside it, Calhoun could see the ship of the invaders. It had been brought down inside the circular structure and was dwarfed by it. It gleamed there.
"And we," said Calhoun, "are going to look for a prosaic, probably messy laboratory which people who make a sport of hunting fellow-humans won't find amusing. Characters like these, Murgatroyd, aren't interested in medical science. They consider themselves conquerors. People have strange ideas!"
"Chee!" said Murgatroyd.
Calhoun spread out his photographs. Kim Walpole had marked where he should go and a route to it. Having been in the city while it was building, he knew even the service-lanes which, being sunken, were not a part of the city's good looks.
"But our enemies," explained Calhoun, "will not deign to use such grubby routes. They consider themselves aristocrats because they were sent as conquerors, whose job it was to clean up the dead bodies of their victims. I wonder what kind of swine are in power in the planetary government which sent them?"
He put away the photos and headed for the city again. He branched off from the rural highway where a turn-off descended into a cut. This low-level road was intended for loads of agricultural produce entering the city. It was strictly utilitarian. It ran below the surface of the park areas and entered the city without pride. It wound between rows of service-gates, behind which waste matter was some day to be assembled to be carted away for fertilizer on the fields. The city was very well designed.
Rolling along the echoing sunken road, Calhoun saw, just once, a ground-car in motion on a far-flung, cobwebby bridge between two tall towers. It was high overhead. Nobody in it would be watching grubby commerce-roads.
The whole affair was very simple indeed. Calhoun brought the car to a stop beneath the overhang of a balconied building many stories high. He got out and opened the gate. He drove the car into the cavernous, so-far-unused lower part of the building. He closed the gate behind him. He was in the center of the city, and his presence was unknown.
He climbed a new-clean flight of steps and came to the sections the public would use. There were glassy walls which changed their look as one moved between them. There were the lifts. Calhoun did not try to use them. He led Murgatroyd up the circular ramps which led upward in case of unthinkable emergency. He and Murgatroyd plodded up and up. Calhoun kept count.
On the fifth level there were signs of use, while all the others had that dusty cleanness of a structure which has been completed but not yet occupied.
"Here we are," said Calhoun cheerfully.
But he had his blaster in his hand when he opened the door of the laboratory. It was empty. He looked approvingly about as he hunted for the storeroom. It was a perfectly equipped biological laboratory, and it had been in use. Here the few doomed physicians awaiting the city's population had worked desperately against the plague. Calhoun saw the trays of cultures they'd made—dried up and dead, now. Somebody had turned over a chair. Probably when the laboratory was searched by the invaders, lest someone not of their kind remained alive in it.
He found the storeroom. Murgatroyd watched with bright eyes as he rummaged.
"Here we have the things men use to cure each other," said Calhoun oracularly. "Practically every one a poison save for its special use! Here's an assortment of spores—pathogenic organisms, Murgatroyd. One could start a plague with them. And here are drugs which are synthesized nowadays, but are descended from the compounds found on the spears of savages. Great helps in medicine. And here are the anaesthetics—poisons, too. These are what I am counting on!"
He chose, very painstakingly. Dextrethyl. Polysulfate. The one marked inflammable and dangerous. The other with the maximum permissible dose on its label, and the name of counteracting substances which would neutralize it. He burdened himself. Murgatroyd reached up a paw. Since Calhoun was carrying something, he wanted to carry something, too.
They went down the circular ramp again. Calhoun searched once more in the below-surface levels of the building. He found what he wanted—a painter's vortex gun which would throw "smoke rings" of tiny paint-droplets at a wall or object to be painted. One could vary the size of the ring at impact from a bare inch to a three-foot spread.
Calhoun cleaned the paint gun. He was meticulous about it. He filled its tank with dextrethyl brought down from the laboratory. He piled the empty containers out of sight.
"This trick," he observed, as he picked up the paint gun again, "was devised to be used on a poor devil of a lunatic who carried a bomb in his pocket for protection against imaginary assassins. It would have devastated a quarter-mile circle, so he had to be handled gently."
He patted his pockets. He nodded.
"Now we go hunting—with an oversized atomizer loaded with dextrethyl. I've polysulfate and an injector to secure each specimen I knock over. Not too good, eh? But if I have to use a blaster I'll have failed."
He looked out a window at the sky. It was now late afternoon. He went back to the gate to the service road. He went out and piously closed it behind him. On foot, with many references to the photomaps, he began to find his way toward the landing grid. It ought to be something like the center of the invaders' location.
It was dark when he climbed other service stairs from the cellar of another building. This was the communications center of the city. It had been the key to the mopping-up process the invaders began on landing. Its call board would show which apartments had communicators in use. When such a call showed, a murder-party could be sent to take care of the caller. Even after the first night, some individual isolated folk might remain—perhaps unaware of what went on. So there would be somebody on watch, just in case a dying man called for the solace of a human voice while still he lived.
There was a man on watch. Calhoun saw a lighted room. Paint gun at the ready, he moved very silently toward it. Murgatroyd padded faithfully behind him.
Outside the door, Calhoun adjusted his curious weapon. He entered. There was a man nodding in a chair before the lifeless board. When Calhoun entered he raised his head and yawned. He turned.
Calhoun sprayed him with smoke rings—vortex rings. But the rings were spinning fissiles of vaporized dextrethyl—that anaesthetic developed from ethyl chloride some two hundred years before, and not yet bettered for its special uses. One of its properties was that the faintest whiff of its odor produced a reflex impulse to gasp. A second property was that—like the ancient ethyl chloride—it was the quickest-acting anaesthetic known.
The man by the call board saw Calhoun. His nostrils caught the odor of dextrethyl. He gasped.
He fell unconscious.
Calhoun waited patiently until the dextrethyl was out of the way. It was almost unique among vapors in that at room temperature it was lighter than air. It rose toward the ceiling. Calhoun moved forward, brought out the polysulfate injector, and bent over the unconscious man. He did not touch him otherwise.
He turned and walked out of the room with Murgatroyd piously marching behind him.
Outside, Calhoun said:
"As one medical man to another, maybe I shouldn't have done that! I doubt these invaders have a competent physician among them. But even he would be apt to think that that man had collapsed suddenly and directly into the coma of the plague. That polysulfate's an assisting anaesthetic. It's not used alone, because when you knock a man out with it he stays out for days. It's used just below the quantity that would affect a man, and then the least whiff of another anaesthetic puts him under, and he can be brought out fast and he's better off all around. But I've got this man knocked out! He'll stay unconscious for a week."
Murgatroyd piped, "Chee!"
"He won't die," said Calhoun grimly, "but he won't come out fighting—unless somebody wakes him earlier. And of course, he is a murderer!"
"Chee!" agreed Murgatroyd.
He reached up a furry paw and took hold of Calhoun's hand. They walked out into the street together.
It is notorious that the streets of a city at night are ghostly and strange. That is true of a city whose inhabitants are only asleep. There is more and worse of eeriness in a deserted city, whose inhabitants are dead. But a city which has never lived, which lies lifeless under the stars because its people never came to live in it—that has the most ghastly feel of all.
Calhoun and Murgatroyd walked hand in paw through such a place. That the invaders felt the same eeriness was presently proved. Calhoun found a place where a light shone and voices came out into the tiny, remote night sounds of Maris III. Men were drinking in an unnecessarily small room, as if crowding together to make up for the loneliness outside. In the still night they made a pigmy tumult with their voices. They banged drunkenly on a table and on the floor.
Calhoun stood in the doorway and held the paint-gun trigger down. He traversed the room twice. Whirling rings of invisible vapor filled the place. Men gasped.
Calhoun waited a long time, because he had put a great deal of dextrethyl into a small space. But presently he went in and bent over each man in turn, while Murgatroyd watched with bright, inquisitive eyes. He arranged one figure so that it seemed to have been stricken while bending over another, fallen companion. The others he carried out, one at a time, and placed at different distances as if they had fallen while fleeing from a plague. One he carried quite a long distance, and left him with dusty knees and hands as if he had tried to crawl when strength failed him.
"They'd have been immunized at pretty well the same time, before they were shipped on this job," Calhoun told Murgatroyd. "It'll seem very plaguelike for them to fall into comas nearly together. If I found men like this, and didn't know what to do, I'd suspect that it was a delayed-action effect of some common experience—like an immunization shot. We'd better try the ship, Murgatroyd."
On the way he passed close to the control-building of the landing grid. There was a light inside it, too. There were four men on watch. Two remained inside, very, very still, when Calhoun went on. The others seemed to have fled and collapsed in the act. They breathed, to be sure. Their hearts beat solidly. But it would not be possible to rouse them to consciousness.
Calhoun didn't get into the ship, though. A chance happening intervened, which seemed an unfavorable one. Its port was locked and his cautious attempt to open it brought a challenge and a blaze of lights.
He fled for the side of the landing grid with blaster-bolts searing the ground all about him. Murgatroyd leaped and pranced with him as he ran.
VI
"The probable complete success of a human enterprise which affects non-co-operating other human beings may be said to vary inversely as the fourth power of the number of favorable happenings necessary for complete success. This formula is admittedly empirical, but its accordance with observation is remarkably close. In practice, the probability of absolute, total success in any undertaking is negligible. For this reason, mathematics and sanity alike counsel the avoidance of complex plannings, and most especially of plans which must succeed totally to succeed at all."Probability and Human ConductFitzgerald
"The probable complete success of a human enterprise which affects non-co-operating other human beings may be said to vary inversely as the fourth power of the number of favorable happenings necessary for complete success. This formula is admittedly empirical, but its accordance with observation is remarkably close. In practice, the probability of absolute, total success in any undertaking is negligible. For this reason, mathematics and sanity alike counsel the avoidance of complex plannings, and most especially of plans which must succeed totally to succeed at all."
Probability and Human ConductFitzgerald
When morning came, Calhoun very wryly considered the situation. He couldn't know the actual state of things, to be sure. He'd been shot at. But even so—though that fact did not allow his hopes to be realized in every detail—the probability of a considerable success remained. It was not likely that the invaders would ascribe the finding of unconscious, stertoriously breathing members of their number to Calhoun. Making men unconscious was not the kind of warfare a plague-refugee would use. Still more certainly, it was not what the invaders themselves would practice. To devise and spread a plague, of course, was not beyond them. That had been done. But they would not disable an enemy and leave him alive. They would murder him or nothing. So when men of their group were found in something singularly close to the terminal coma of the plague, they'd think them victims. They'd guess that their supposed immunity was only to the early symptoms, not to the final ones and death.
It should not be an encouraging opinion.
But this morning Calhoun found himself hungry. He looked remorsefully at Murgatroyd.
"I gave our rations to those refugees," he said regretfully. "I took no thought for the morrow—which has turned out to be today. I'm sorry, Murgatroyd!"
Murgatroyd said nothing.
"Maybe," suggested Calhoun, "we can find some of these invaders at a meal."
It was reckless, but recklessness was necessary in the sort of thing Calhoun had started. He and Murgatroyd ventured out into the streets. The emptiness of the city was appalling. If it had been dilapidated, if it had been partly ruined—the emptiness might have seemed somehow romantic. But every building was perfect. Each was complete but desolately unused.
Calhoun spotted a ground-car at a distance, stopped before a long, low, ground-hugging structure near the landing grid. It was perfectly suited to be the headquarters of the strangers in the city. Calhoun considered it for a long time, peering at it from a doorway.
"We shouldn't try it," he said at last. "But we probably will. If we can make these characters so panic-stricken that they run out of the city like the earlier refugees—it would be a highly favorable happening. They might do it if their bosses were knocked out by what they thought was the plague. And besides, we should get a meal out of it. There'll be food in there."
He backtracked a long way. He darted across a road with Murgatroyd scampering beside him. He stalked the building, approaching it behind bushes, carrying the paint gun. He reached its wall. He began to crawl around the outside to reach the doorway. He heard voices as he passed the first windows.
"But I tell you we're immune!" cried a voice furiously. "It can't be the same thing those Dettrans died from! It can't! And there was that man who ran from the ship last night—"
Calhoun crawled on. Murgatroyd skipped. Calhoun heard an exclamation behind him. He turned his head, and Murgatroyd was fifteen feet away from the building-wall, and plainly visible to those inside. And he'd been seen fleeing with Calhoun from the ship.
Calhoun swore softly. He ran. He reached the door before which a ground-car stood. He wrenched it open and set the paint gun at work firing a steady stream of vortex rings into the interior. He drew his blaster and faced the outside world.
There was a crashing of glass. Somebody had plunged out a window. There were rushing feet inside. They'd be racing toward this doorway from within. But the hallway—anteroom—foyer—whatever was immediately inside the door would be filled with dextrethyl vapor. Men would gasp and fall.
A man did fall. Calhoun heard the crash of his body to the floor. But also a man came plunging around the building's corner, blaster out, searching for Calhoun. But he had to sight his target and then aim for it. Calhoun had only to pull trigger. He did.
Shoutings inside the building. More rushing feet. More falls. Then there was the beginning of the rasping snarl of a blaster, and then a cushioned, booming, roaring detonation which was the explosive dextrethyl vapor, ignited by it. The blast lifted the building's roof. It shattered partitions. It blew every window out.
Calhoun sprinted for the ground-car. A blaster-bolt flashed past him. He halted and deliberately traversed the building with the trigger held down. Smoke and flame leaped up. At least one more invader crumpled. Calhoun heard a voice yelling inside somewhere.
"We're attacked! Those refugees are throwing bombs! Rally! Rally! We need help!"
It would be a broadcast call for assistance. Wherever men lolled or loafed or tried desultorily to find something to loot, they would hear it. Even the standby crew in the spaceship would hear it. Those who repaired the grid-transformers Calhoun had burned out would hear it. Men would come running. Hunters would come. Men in cars—
Calhoun snatched Murgatroyd to the seat beside him. He turned the key and the tires screamed and he shot away.
The highways were of course, superb. He raced forward, and the car's communicator began to mutter as somebody in the undamaged part of the building chattered that he'd gotten in a car and away. It described his course. It commanded that he be headed off. It hysterically demanded that he be killed, killed, killed—
Another voice took its place. This voice was curt and coldly furious. It snapped precise instructions.
Calhoun found himself on a gracefully curving, rising road. He was midway between towers when another car flashed toward him. He took his blaster in his left hand. In the split second during which the cars passed each other, he blasted it. There was a monster surge of smoke and flame as the stricken car's Duhanne cell shorted and vaporized half the metal of the car itself.
There came other voices. Somebody had sighted the explosion. The voice in the communicator roared for silence.
"You," he rasped. "If you got him, report yourself!"
"Chee-chee-chee!" chattered Murgatroyd excitedly.
But Calhoun did not report.
"He got one of us," raged the icy voice. "Get ahead of him! And blast him!"
Calhoun's car went streaking down the far side of the traffic-bridge. It rounded a curve on two wheels. It flashed between two gigantic empty buildings and came to a sideway, and plunged into that, and came again to a division and took the left-hand turn, and next time took the right. But the muttering voices continued in the communicator. A voice, by name, was ordered to the highest possible bridge from which it could watch all lower-level roadways. Others were to post themselves here, and there—and to stay still! A group of four cars was coming out of the storage-building. Blast any single car in motion. Blast it! And report, report, report—
"I suspect," said Calhoun to the agitated Murgatroyd beside him, "that this is what is known as military tactics. If they ring us in—There aren't but so many of them, though. The trick for us is to get out of the city. We need more choices for action. So—"
The communicator panted a report of his sighting, from a cobweblike bridge at the highest point of the city. He was heading—
He changed his heading. He had so far seen but one car of his pursuers. Now he went racing along empty, curving highways, among untenanted towers and between balconied walls with blank-eyed windows gazing at him everywhere.
It was nightmarish because of the magnificence and the emptiness of the city all about him. He plunged along graceful highways, across delicately arched bridges, through crazy ramifications of its lesser traffic arteries—and he saw no motion anywhere. The wind whistled past the car windows, and the tires sang a high-pitched whine, and the sun shone down and small clouds floated tranquilly in the sky. There was no sign of life or danger anywhere on the splendid highways or in the heart-wrenchingly beautiful buildings. Only voices muttered in the communicator of the car. He'd been seen here, flashing around a steeply banked curve. He'd swerved from a waiting ambush by pure chance. He'd—
He saw green to the left. He dived down a sloping ramp toward one of the smaller park areas of the city.
And as he came from between the stone guard rails of the road, the top of the car exploded over his head. He swerved and roared into dense shrubbery, jerked Murgatroyd free despite thetormal'sclinging fast with all four paws and his tail, and dived into the underbrush.
He ran, swearing and plucking solidified droplets of still-hot metal from his garments and his flesh. They hurt abominably. But the man who'd fired wouldn't believe he'd missed, followed as his blasting was by the instant wrecking of the car. The man who'd fired would report his success before he moved to view the corpse of his supposed victim. But there'd be other cars coming. At the moment it was necessary for Calhoun to get elsewhere, fast.
He heard the rushing sound of arriving cars while he panted and sweated through the foliage of the park. He reached the far side and a road, and on beyond there was a low stone wall. He knew instantly what it was. Service highways ran in cuts, now and again roofed over to hide them from sight, but now and again open to the sky for ventilation. He'd entered the city by one of them. Here was another. He swung himself over the wall and dropped. Murgatroyd recklessly and excitedly followed.
It was a long drop, and he was staggered when he landed. He heard a soft rushing noise above. A car raced past. Instants later, another.
Limping, Calhoun ran to the nearest service-gate. He entered and closed it. Scorched and aching, he climbed to the echoing upper stories of this building. Presently he looked out. His car had been wrecked in one of the smaller park areas of the city. Now there were other cars at two-hundred-yard intervals all about it. It was believed that he was in the brushwood somewhere. Besides the cars of the cordon, there were now twenty men on foot receiving orders from an authoritative figure in their midst.
They scattered. Twenty yards apart, they began to move across the park. Other men arrived and strengthened the cordon toward which he was supposed to be driven. A fly could not have escaped.
Those who marched across the park began methodically to burn it to ashes before them with their blasters.
Calhoun watched. Then he remembered something and was appalled. Among the fugitives in the glade, Kim Walpole had asked hungrily if they whose lives he had saved could not do something to help him. And he'd said that if they saw the smoke of a good-sized fire in the city they might investigate. He'd had no faintest intention of calling on them. But they might see this cloud of smoke and believed he wanted them to come and help!
"Damn!" he said wryly to Murgatroyd. "After all, there's a limit to any one series of actions with probable favorable chance consequences. I'd better start a new one. We might have whittled them down and made the unwhittled ones run away, but I had to start using a car! And then they'd try to blame me for everything. So—we start all over with a new policy."
He explored the building quickly. He prepared his measures. He went back to the window from which he'd looked. He cracked its window.
He opened fire with his blaster. The range was long, but with the beam cut down to minimum spread he'd knocked over a satisfying number of the men below before they swarmed toward the building, sending before them a barrage of blaster-fire that shattered the windows and had the stone façade smoking furiously.
"This," said Calhoun, "is an occasion where we have to change their advantage in numbers and weapons into an unfavorable circumstance for them. They'll be brave because they're many. Let's go!"
He met the two ground-car loads of refugees with his arms in the air. He did not want to be shot down by mistake. He said hurriedly, when Kim and the other lean survivors gathered about him:
"Everything's all right. We've a pack of prisoners but we won't bother to feed them intravenously for the moment. How'd you get the ground-cars?"
"Hunters," said Kim savagely. "We found them and killed them and took their cars. We found some other refugees, too, and I cured them—at least they will be cured. When we saw the smoke we started for the city. Some of us still have the plague, but we've all had our serum shots." His face worked. "When we started for the city, another car overtook us. Naturally he wasn't suspicious of a car! We blasted him. Half of us have arms, now."
"I don't think we need them," said Calhoun. "Our prisoners are quite peacefully sleeping. They stormed a building where I'd fired on them, and I'd dumped some dextrethyl in the air-conditioning system. They keeled over. Later, Murgatroyd and I went in and made their slumber more ... ah ... lasting with polysulfate. The few who weren't caught were ... ah ... demoralized. I think the city's clean, now. But we've got to get to the landing-grid control room. There are some calls coming in from space. I think the first shipload of colonists is arriving. I didn't answer, so they went in orbit around the planet. I want you people to talk to them."
"We'll bring their ship down," said the bearded man hungrily, "and blast them as they come out the exit port!"
Calhoun shook his head.
"To the contrary," he said regretfully. "You'll put on the clothes of some of our prisoners. You'll tell the arriving colonists that the plague hit you, too. You'll pretend to be one of the characters we really have safely sleeping, and you'll say all the rest have been bowled over by the plague that was sowed here to win the planet for the characters you're talking to. If they land, they'll die—or so you'll tell them. And so they will all go home, very unhappy, and they'll tell the public about it. And there will be no more shiploads of colonists arriving. We don't want them. If we persuade them to go home and not come back, there are fewer chances of unfavorable consequences to us."
The bearded man growled. But later he was one of the most convincing of the scarecrow figures whose images appeared in the vision-plates of the ship overhead. He was especially pathetic and alarming. When he'd finished, there'd have been a mass mutiny of the passengers had the spaceship skipper tried to land them.
Later, all the fugitives were very conscientious about bringing the captive invaders out of the lethargy that had been begun by dextrethyl and reinforced by polysulfate. They enjoyed their labor, after Calhoun explained.
"They came in their own ship," he said mildly, "and it's still in the landing grid—which they repaired for us, by the way. And I've been aboard the ship with Kim, here, and we've smashed their drive and communicators, and wrecked their Duhanne circuits. We took out the breech-plugs of their rockets and dumped their rocket fuel. Of course we removed their landing boats. So we're going to put them in their ship and hoist them up to space with the landing grid, and we're going to set them in a lovely orbit, to wait until we've time to spare for them. Up there they can't run or land or even signal if another shipload of colonists turns up. They'll feed themselves and they won't need guarding, and they'll be quite safe until we get help from Dettra. And that will come as soon as the Med Service has told Dettra that it wasn't a plague but an invasion that seemed to take their colony away from them."
"But—" That was Kim Walpole, frowning.
"I'm bringing my ship to the grid," said Calhoun, "and we'll recharge my Duhanne cells and replace my vision screens. I can make it here on rocket power, but it's a long way back to Headquarters. So I'll report, and a field team will come here from Med Service to get the exact data on the plague, and just how the synergy factor worked, and to make everything safe for the people the city was built for. Incidentally, I've a tiny blood-sample from Helen that they can get to work on for the bacteriology."
Kim said, frowning:
"I wish we could do something for you!"
"Put up a statue," said Calhoun dryly, "and in twenty years nobody will know what it was for. You and Helen are going to be married, aren't you?" When Kim nodded, Calhoun said, "In course of time, if you remember and think it worth while, you may inflict a child with my name. That child will wonder why, and ask, and so my memory will be kept green for a full generation!"
"Longer than that!" insisted Kim. "You'll never be forgotten here!"
Calhoun grinned at him.
Three days later, which was six days longer than he'd expected to be aground on Maris III, the landing grid heaved the little Med Ship out to space. The beautiful, nearly-empty city dwindled as the grid-field took the tiny spacecraft out to five planetary diameters and there released it. And Calhoun spun the Med Ship about and oriented it carefully for that place in the Cephis cluster where Med Service Headquarters was, and threw the overdrive switch.
The universe reeled. Calhoun's stomach seemed to turn over twice, and he had a sickish feeling of spiraling dizzily in what was somehow a cone. He swallowed. Murgatroyd made gulping noises. There was no longer a universe preceptible about the ship. There was dead silence. Then those small random noises began which have to be provided if a man is not to crack up in the dead stillness of a ship traveling at thirty times the speed of light.
Then there was nothing more to do. In overdrive travel there is never anything to do but pass the time away.
Murgatroyd took his right-hand whiskers in his right paw and licked them elaborately. He did the same to his left-hand whiskers. He contemplated the cabin, deciding upon a soft place in which to go to sleep.
"Murgatroyd," said Calhoun severely, "I have to have an argument with you! You imitate us humans too much! Kim Walpole caught you prowling around with an injector, starting to give our prisoners another shot of polysulfate! It might have killed them! Personally, I think it would have been a good idea, but in a medical man it would have been most unethical. We professional men have to curb our impulses! Understand?"
"Chee!" said Murgatroyd. He curled up and wrapped his tail meticulously about his nose, preparing to doze.
Calhoun settled himself comfortably in his bunk. He picked up a book. It was Fitzgerald on "Probability and Human Conduct."
He began to read as the ship went on through emptiness.
THE END