Chapter V

"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 Conduct_
Fitzgerald

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 family _solanaceae_--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.