Chapter IV

"Statistically, it must be recognized that no human action is
without consequences to the man who acts. Again statistically, it
must be recognized that the consequences of an action tend with
strong probability to follow the general pattern of the action. A
violent action, for example, has a strong probability of violent
consequences, and since some at least of the consequences of an
act must affect the person acting, a man who acts violently exposes
himself to the probability that chance consequences which affect
him, if unfavorable, will be violently so."

_Probability and Human Conduct_
Fitzgerald

Murgatroyd had been inoculated with a blood-sample from the girl Helen some three hours or less before sunset. But it was one of the more valuable genetic qualities of the _tormal_ race that they reacted to bacterial infection as a human being reacts to medication. Medicine on the skin of a human being rarely has any systemic effect. Medication on mucus membrane penetrates better. Ingested medication--medicine that is swallowed--has greater effectiveness still. But substances injected into tissues or the blood-stream have most effect of all. A centigram of almost any drug administered by injection will have an effect close to that of a gram taken orally. It acts at once and there is no modification by gastric juices.

Murgatroyd had had half a cubic centimeter of the girl's blood injected into the spot on his flank where he could feel no pain. It contained the unknown cause of the plague on Maris III. Its effect as injected was incomparably greater than the same infectious material smeared on his skin or swallowed. In either such case, of course, it would have had no effect at all, because _tormals_ were to all intents and purposes immune to ordinary contagions. Just as they had a built-in unit in their digestive tract to cause the instant rejection of unwholesome food, their body-cells had a built-in ability to produce antibodies immediately the toxin of a pathogenic organism came into contact with them. So _tormals_ were effectively safe against any disease transmitted by ordinary methods of infection. Yet if a culture of pathogenic bacteria--say--were injected into their blood stream, their whole body set to work to turn out antibodies because all their body was attacked. And all at once. There was practically no incubation-period.

Murgatroyd, who had been given the plague in mid-afternoon, was reacting violently to its toxins by sunset. But two hours after darkness fell he arose and said shrilly, "_Chee-chee-chee!_" He'd been sunk in heavy slumber. When he woke, there was a small fire in the glade, about which the exhausted, emaciated fugitives consulted with Calhoun. Calhoun was saying bitterly:

"Those characters in the city are immune! They have to be! And they know they're immune, or they wouldn't risk contagion by murdering you or handling the bodies of plague-victims to burn them! So they have to know all about the plague--and they knew it before they arrived! They came because they knew! That's why I shot that man with the crossbow, instead of taking a blaster to him. I meant to wound him so I could make him answer questions, but it's not an accurate weapon and I killed him instead. I got very little from the stuff in his pockets. The only significant thing was a ground-car key, and even that means only there's a car waiting somewhere for him."

The gaunt young man said drearily:

"He didn't come from Dettra, our home planet. Fashions are different on different worlds. His foot-wear was like a style we had on Dettra four years back, and his body-clothing has fasteners we don't use."

Murgatroyd saw Calhoun and rushed to him, embracing his legs with enthusiasm and chattering shrilly of his relief at finding the man he knew. The skeletonlike plague-victims stared at him.

"This," said Calhoun with infinite relief, "is Murgatroyd. He's had the plague and is over it. So now we'll get you people cured. I wish I had better light!"

He counted Murgatroyd's breathing and listened to his heart. Murgatroyd was in that state of boisterous good health which is normal in any lower animal, but amounts to genius in a _tormal_. Calhoun regarded him with satisfaction.

"All right!" he said. "Come along!"

* * * * *

He plucked a brand of burning resinous stuff from the campfire. He handed it to the gaunt young man and led the way. Murgatroyd ambled complacently after him. Calhoun stopped under one of the unoccupied shelters and got out his lab kit. He bent over Murgatroyd. What he did, did not hurt. When he stood up, he squinted at the red fluid in the instrument he'd used.

"About fifteen CCs," he observed. "This is strictly emergency stuff I'm doing now. But I'd say that there's an emergency."

The gaunt young man said:

"I'd say you've doomed yourself. The incubation-period seems to be about six days. It took that long to develop among the doctors we had in the office staff."

Calhoun opened a compartment of the kit, whose minuscule test tubes and pipettes gleamed in the torchlight. He absorbedly transferred the reddish fluid to a miniature filter-barrel, piercing a self-healing plastic cover to do so. He said:

"You're pre-med? The way you talk--"

"I was an interne," said Kim. "Now I'm pre-corpse."

"I doubt that last," said Calhoun. "But I wish I had some distilled water--This is anticoagulant." He added the trace of a drop to the sealed, ruddy fluid. He shook the whole filter to agitate it. The instrument was hardly larger than his thumb. "Now a clumper--" He added a minute quantity of a second substance from an almost microscopic ampule. He shook the filter again. "You can guess what I'm doing. With a decent lab I'd get the structure and formula of the antibody Murgatroyd has so obligingly turned out for us. We'd set to work to synthesize it. In twenty hours, lab time, we ought to have it coming out of the reaction-flasks in quantity. But there is no lab."

"There's one in the city," said the gaunt young man hopelessly. "It was for the colonists who were to come. And we were staffed to give them proper medical care. When the plague came, our doctors did everything imaginable. They not only tried the usual culture tricks, but they cultured samples of every separate tissue in the fatal cases. They never found a single organism--even in the electron microscopes--that would produce the plague." He said with a sort of weary pride, "Those who'd been exposed worked until they had it, then others took over. Every man worked as long as he could make his brain work, though."

Calhoun squinted through the glass tube of the filter at the sputtering torch.

"Almost clumped," he observed. Then he said, "Did you ever hear of a man named Pasteur? One of his first discoveries was that one could get an effectively pure culture of a pathogenic organism by giving the disease to an experimental animal. Better ways were found later, but one still expects a pure culture in a patient who has a disease really badly. What did the lab turn up?"

Kim shook his head.

"Nothing. The bacteriological survey of the planet had been thorough. Oral and intestinal flora were normal. Naturally, the local bacteria couldn't compete with the strains we humans have learned to live with. They couldn't symbiotize. So there wasn't anything unknown. There wasn't any cause of the plague."

Calhoun began to work the filter plunger, by the wavering light of the torch. The piston was itself the filter, and on one side a clear, mobile liquid began very slowly to appear.

"Mutated standard bug? Still, if your doctors did cultures and couldn't reproduce the disease--"

"They could pass it," said Kim bitterly, "but they could never find what carried it! No pure culture would!"

* * * * *

Calhoun watched the clear fluid develop on the delivery side of the filtering piston. The job got done. There was better than twelve cubic centimeters of clear serum on the delivery side, and an almost solid block of clumped blood cells on the other. He drew off the transparent fluid with a fine precision.

"We're doing biochemistry under far from aseptic conditions," he said wryly, "but the work has to be done and we have to take the risk. Anyhow, I'm getting a feeling that this isn't any ordinary plague. A normal pathogenic organism should have been turned up by your doctors."

"It wasn't," said Kim.

"So," said Calhoun, "maybe it isn't one isolatable organism. Maybe the disease-producing mechanism simply isn't there when you make pure cultures of the separate strains of virus and microbe. Murgatroyd was a pretty sick animal. I've only known of one previous case in which a _tormal_ reacted as violently as Murgatroyd did. That one had us sweating."

"If I were going to live," said Kim grimly, "I might ask what it was."

"Since you're going to," Calhoun told him, "I'll tell you though you don't. It was a pair of organisms. Their toxins acted synergically together. Separately they were innocuous. Together they were practically explosive. That one was the devil to track down!"

He went back across the glade. Murgatroyd came skipping after him, scratching at the anaesthetic patch on his hide, which he sometimes seemed to notice not because it felt oddly, but because it did not feel at all.

"You," said Calhoun briefly to Helen Jons, "you go first. This is an antibody serum. You may itch afterward, but I doubt it. Your arm, please."

She bared her rather pitifully thin arm. He gave her practically a CC of fluid which--plus blood-corpuscles and some forty-odd other essential substances--had been circulating in Murgatroyd's blood stream not long since. The blood-corpuscles had been clumped and removed by one compound plus the filter, and the anticoagulant had neatly modified most of the others. In a matter of minutes, the lab kit had prepared as usable a serum as any animal-using technique would produce. Logically, the antibodies it contained should be isolated and their chemical structure determined. They should be synthesized, and the synthetic antibody-complex administered to plague-victims. But Calhoun faced a small group of people doomed to die. He could only use his field kit to produce a small-scale miracle for them. He could not do a mass production job.

"Next!" said Calhoun. "Tell them what it's all about, Kim!"

The gaunt young man bared his own arm.

"If what he says is so, this will cure us. If it isn't so, nothing can do us any harm!"

And Calhoun briskly gave them, one after another, the shots of what ought to be a curative serum for an unidentified disease which he suspected was not caused by any single germ, but by a partnership. Synergy is an acting-together. Charcoal will burn quietly. Liquid air will not burn at all. But the two together constitute a violent explosive. This is analogous to synergy. The ancient simple drug sulfa is not intoxicating. A glass of wine is not intoxicating. But the two together have the kick of dynamite. Synergy, in medicine, is a process in which when one substance with one effect is given in combination with another substance with another effect, the two together have the consequences of a third substance intensified to fourth or fifth or tenth power.

* * * * *

"I think," said Calhoun when he'd finished, "that by morning you'll feel better--perhaps cured of the plague and only weak from failure to force yourselves to take nourishment. If it turns out that way, I advise you all to get as far away from the city as possible for a considerable while. I think this planet is going to be repopulated. I suspect that shiploads of colonists are on the way here now--but not from Dettra, which built the city. And I definitely guess that, sick or well, you're going to be in trouble if or when you contact the new colonists."

They looked tiredly at him. They were a singular lot of people. Each one seemed half-starved, yet their eyes had not the brightness of suffering. They looked weary beyond belief, and yet there was not self-neglect. They were of that singular human type which maintains human civilization against the inertia of the race--because it drives itself to get needed things done. It is not glamorous, this dogged part of mankind which keeps things going. It is sometimes absurd. For dying folk to wash themselves, when even such exertion calls for enormous resolution, is not exactly rational. To help each other try to die with dignity was much more a matter of self-respect than of intellectual decision. But as a Med Ship man, Calhoun viewed them with some warmth. They were the type that has to be called on when an emergency occurs and the wealth-gathering type tends to flee and the low-time-sense part of a population inclines to riot or loot or worse.

Now they waited listlessly for their own deaths.

"There's no exact precedent for what's happened here," explained Calhoun. "A thousand years or so ago there was a king of France--a country back on old Earth--who tried to wipe out a disease called leprosy by executing all the people who had it. Lepers were a nuisance. They couldn't work. They had to be fed by charity. They died in inconvenient places and only other lepers dared handle their bodies. They tended to throw normal human life out of kilter. That wasn't the case here. The man I killed wanted you dead for another reason. He wanted you dead right away."

The gaunt Kim Walpole said tiredly:

"He wanted to dispose of our bodies in a sanitary fashion."

"Nonsense!" snapped Calhoun. "The city's infected. You lived, ate, breathed, walked in it. Nobody can dare use that city unless they know how the contagion's transmitted, and how to counteract it. Your own colonists turned back. These men wouldn't have landed if they hadn't known they were safe!"

There was silence.

"If the plague is an intended crime," added Calhoun, "you are the witnesses to it. You've got to be gotten rid of before colonists from somewhere other than Dettra arrive here."

The dark-bearded man growled:

"Monstrous! Monstrous!"

"Agreed," said Calhoun. "But there's no interstellar government, now, any more than there was a planetary government in the old days back on Earth. So if somebody pirates a colony ready to be occupied, there's no authority able to throw them out. The only recourse would be war. And nobody is going to start an interplanetary war! Not with the bombs that can be landed! If the invaders can land a population here, they can keep it here. It's piracy, with nobody able to do anything to the pirates." He paused, and said with irony: "Of course they could be persuaded that they were wrong."

But that was not even worth thinking about. In the computation of probabilities in human conduct, self-interest is a high-value factor. Children and barbarians have clear ideas of justice due to them, but no idea at all of justice due from them. And though human colonies spread toward the galaxy's rim, there was still a large part of every population which was civilized only in that it could use tools. Most people still remained comfortably barbaric or childish in their emotional lives. It was a fact that had to be considered in Calhoun's profession. It bore remarkably on matters of health.

"So you'll have to hide. I think permanently," Calhoun told them. "But in the morning, after I've checked on you people again, I think I'll go into the city and see what I can do about it. Try to rest now. You should all feel much better in the morning."

Kim Walpole said abruptly:

"You've been exposed to the plague. Have you protected yourself?"

"Not yet," acknowledged Calhoun. "Give me a quarter of a CC."

He handed the injector to the gaunt young man. He noted the precision with which Kim handled it. Then he helped get the survivors of the original group--there were six of them--to the leafy beds under the shelters. They were very quiet--even more quiet than their illness demanded. They were very polite. The old man and woman who had struggled back to the glade together made an especial attempt to bid Calhoun good night with the courtesy appropriate to city folk of tradition.

Calhoun settled down to keep watch through the night. Murgatroyd snuggled confidingly close to him. There was silence.

* * * * *

But not complete silence. The night of Maris III was filled with tiny noises, and some not so tiny. There were little squeaks which seemed to come from all directions, including overhead. There were chirpings which were definitely at ground-level. There was a sound like effortful grunting somewhere in the direction of the rampart of hills. In the lowlands there was a rumbling which moved very slowly from one place to another. By its rate of motion, Calhoun guessed that a pack or herd of small animals was making a night-journey and uttering deep-bass noises as it traveled.

He debated certain grim possibilities. The man he'd killed had had a ground-car key in his pocket. He'd probably come out in a powered vehicle. He might have had a companion, and the method of hunting down fugitives--successful, in his case--was probably well established. That companion might come looking for him, so watchfulness was necessary.

Meanwhile--the plague. The idea of synergy was still most plausible. Suppose the toxins--the poisonous metabolic products--of two separate kinds of bacteria combined to lessen the ability of the blood to carry oxygen and scavenge away carbon dioxide? It would be extremely difficult to identify the pair, and the symptoms would be accounted for. No pure culture of any organism to be found would give the plague. Each, by itself, would be harmless. Only a combination of two would be injurious. And if so much was assumed--why--if the blood lost its capacity to carry oxygen, mental listlessness would be the first symptom of all. The brain requires a high oxygen-level in its blood-supply if it is to work properly. Let a man's brain be gradually, slowly, starved of oxygen and all the noted effects would follow. His other organs would slow down, but at a lesser rate. He would not remember to eat. His blood would still digest food and burn away its own fat--though more and more sluggishly--while his brain worked only foggily. He would become only semiconscious, and then there would come a time of coma when unconsciousness claimed him and his body lived on only as an idling machine--until it ran out of fuel and died.

Calhoun tried urgently to figure out a synergic combination which might make a man's blood cease to do its work. Perhaps only minute quantities of the dual poison might be needed--like an antivitamin or an antienzyme, or--

The invaders of the city were immune. Quite possibly the same antibodies Murgatroyd had produced were responsible for their safety. Somewhere, somebody had very horribly used the science of medicine to commit a monstrous crime. But the science of medicine--

A savage idea came to Calhoun. Its practicality might depend on the number of men in the city. But his eyes burned.

He heard a movement across the glade. He reached for his blaster. Then he saw where the motion was. It was Kim Walpole, intolerably weary, trudging with infinite effort to where Helen Jons lay. Calhoun heard him ask heavily:

"You're all right?"

"Yes, Kim," said the girl softly. "I couldn't sleep. I'm ... wondering if we can hope."

Kim did not answer.

"If we live--" said the girl yearningly, and stopped.

Calhoun felt that he ought to put his fingers in his ears. The conversation was strictly private. But he needed to be on guard. So he coughed, to give notice that he heard. Kim called to him across the starlit glade.

"Calhoun."

"Yes," said Calhoun. "If you two talk, I suggest that you do it in whispers. I want to listen, in case the man I killed had friends who'll come looking for him. Did you get his blaster, by the way?"

"Yes," said Kim from the darkness across the way.

"Good!" said Calhoun. "Keep it. And against all medical ethics, I advise you to use it freely if you find suitable targets. But now, just talk quietly if you can."

He settled back. Murgatroyd stirred and cuddled closer against him without wakening. There was the faintest possible murmuring of voices where Kim Walpole and the girl Helen talked wistfully of the possibility of hope.

Calhoun felt very lonely, despite the violent activities he foresaw for the morrow. He almost envied Kim Walpole. But he could not have traded places with him. It wouldn't have been a fair trade. Calhoun was quite confident that--via Murgatroyd--the folk in the glade had a very fair chance of living for some time yet.

His own chances, considering what he had to do, were more nearly zero. Just about zero, when considered dispassionately.