Chapter 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 Conduct_
Fitzgerald

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 the _tormal's_ clinging 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