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 no 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 to 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. But 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 handled 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 and his friends 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 the place." 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 contagion, and health, and life itself.
"You'll have to hide. Perhaps permanently," he told them. "It depends partly on what happens to me, however. I have to go to the city. There's a very serious health problem there."
Kim said with irony, "In the city? Everybody's healthy there. They're so healthy that they come out to hunt us down for sport!"
"Considering that the city's thoroughly infected, their immunity is a health problem," said Calhoun. "But besides that, it looks like the original cause of the plague is there, too. I'd guess that the originator of this plague is technical director of the exterminating operation that's in progress on this planet. I'd guess he's in the ship that brought the butcher-invaders. I'd be willing to bet that he's got a very fine laboratory on the ship."
Kim stared at him. He clenched and unclenched his hands.
"And I'd say it ought to be quite useless to fight this plague before that man and that laboratory were taken care of," said Calhoun. "You people are probably all right. I think you'll wake up feeling better. You may be well. But if the plague is artificial, if it was developed to make a colony planet useless to the world that built it, but healthy for people who want to seize it . . ."
"What?"
"It may be the best plague that was developed for the purpose, but you can be sure it's not the only one. Dozens of strains of deadly bugs would have to be developed to be sure of getting the deadliest. Different kinds of concealment would have to be tried, in case somebody guessed the synergy trick, as I did, and could do something about the first plague used. There'd have to be a second and third and fourth plague available. You see?"
Kim nodded, speechless.
"A setup like that is a real health hazard," said Calhoun. "As a Med Service man, I have to deal with it. It's much more important than your life or mine or Murgatroyd's. So I have to go into the city to do what can be done. Meanwhile, you'd better lie down now. Give Murgatroyd's antibodies a chance to work."
Kim started to move away. Then he said, "You've been exposed. Have you protected yourself?"
"Give me a quarter-cc shot," said Calhoun. "That should do."
He handed the injector to the gaunt young man. He noted the deftness with which Kim handled it. Then he helped get the survivors of the original group—there were six of them now—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'd struggled back to the glade together made a special effort 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 faint. 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 in the direction of the 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, there was 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 the two would be injurious. And if so much was assumed, and 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.