One Step From Earth

The Life Preservers

RUBBLE AND DIRT had once been piled high to cover the object, then the resulting mound had been hidden beneath a stone cairn. Either the stones had been badly fitted together or the seasons had been most unkind, because the cairn was now only a tumbled ruin, an ugly jumble of rocks no higher than a man's waist. The rubble and dirt had been washed away by the rains of centuries so that now, rising from a foliage-covered hillock, there stood the object that great labor had worked to conceal: a giant frame of pitted, corroded metal three meters high and twice as long. Set into this frame was what appeared to be a slab of slatelike material. It was hard, it had not been scratched or dented at all during the long years, and was coated with dust and adhesive debris. Around the tumbled stones and the framed slab stretched a tufted meadow bordered by a growth of stunted trees. Drab hills were visible in the distance, barely seen through a thin mist, merging into a sky of the same indifferent color. The white pebbles of a recent hail shower lay unmelted in the hollows. A bird, brown on the back and light gray below, pecked desultorily at the grasses on the mound.

The change was abrupt. In an instant, too small a measure of time to be seen, the framed slab changed color. It was now a deep black, a strange color that was more lack of color than anything else. At the same moment its surface must have altered because all of the dust and debris fell from it. A detached cocoon from some large insect dropped next to the bird, startling it, so that it flew away in a sudden flurry of motion.

From the blackness a man emerged, stepping out, three-dimensional and sound, as though he were stepping through a door. He emerged, suddenly, and crouched low, looked about suspiciously. He wore a sealed suit to which were attached many complex devices, his head was contained in a transparent helmet, and he held a pistol ready in his hand. After a moment he straightened up, still alert, and spoke into the microphone fixed before his lips. A length of flexible wire ran from the microphone, through a fixture in his helmet, and back to the black surface into which it vanished.

"First report. Nothing moving, no one in sight. Thought I saw something like a bird then, can't be sure. Must be winter or a cold planet, small growths and trees, low clouds, snow — no, I think it's hail — on the ground. All instruments recording well. I'm going to look at the controls now. They are concealed behind a mound of soil and rocks; I'll have to dig down for them."

After a last searching glance around, he slipped his weapon back into its holster on his leg and took a rodlike instrument from his pack. He held it at arm's length, switched it, on, and touched it to the ground where it covered the right-hand side of the frame. The soil stirred, boiling away in a cloud of fine particles, while pebbles and small stones bounced in all directions. With greater effort larger stones were moved, grating and crashing to one side when the metal tip was placed beneath them. More and more of the metal frame was revealed. It widened out below the ground and appeared to be marred by a gaping opening. The man stopped suddenly when he saw this and, after another searching look in all directions, he bent down for a closer examination.

"Reason enough here, looks like deliberate sabotage. Warped edges to the hole, an explosion, powerful. Blew out all the controls and deactivated the screen. I can fix a unit—"

His words ended in a grunt of pain as the short wooden shaft penetrated his back. It was feathered and notched. He dropped to his knees and turned about, painfully yet still quickly, and his pistol spat out a continuous stream of small particles that exploded with surprising power when they contacted anything. He laid down this curtain of fire twenty meters away, an arc of explosions and dust and smoke. There was something pressing up against the fabric of his suit over his chest and when he touched it with his fingertips he could feel a sharp point just emerging from his flesh. He was also aware of the seep of blood against his skin. As soon as the arc of explosions had cut a 180-degree swath he stood, stumbled, and half fell against the darkness from which he had emerged. He vanished into it as though into a pool of water and was gone.

A thin cold wind dispersed the dust and everything was silent once again.

The destroyed village was a place of revolting death. As always reality went far beyond imagination, and no director would have set his stage so clumsily. Untouched houses stood among the burnt ones. A draft animal lay dead between the poles of a farm wagon, its outstretched nose touching the face of a plague victim whose limbs had been gnawed by wild animals. There were other corpses tumbled clumsily about, and undoubtedly more of them mercifully out of sight inside the buildings. An arm hung down from behind the partially closed blinds of a window, a mute indication of what lay within. The projected scene was three dimensional, filling one entire wall of the darkened auditorium, real enough to shock. Which was its purpose. The commentator's voice was flat and emotionless, counterpoint to the horrors of the scene.

"Of course this occurred during the early founding days and our forces were spread thin. Notification was received and registered, but because of the deteriorating situation on Lloyd no teams were dispatched. Subsequent analysis proved that a single unit could have been spared without altering the Lloyd effort in any measurable manner, and this action would have altered drastically the results seen here. The death figures, as they stood at the end of the emergency, reached seventy-six point thirty-two of the planetary population…"

The communicator in Jan Dacosta's pocket hummed quietly and he placed it to his ear and actuated it.

"Doctor Dacosta, please report to Briefing Central."

He almost jumped to his feet, despite the past weeks of training. But he controled himself, stood slowly, then left the auditorium with no evidence of haste. A few people looked up to watch him go, then turned back to the training film. Jan had seen enough training films. Perhaps this call from Briefing meant that a mission was finally going out, that he could do something at last rather than look on, impotently, at more films. He was on alert standby, had been for days. This could be a mission. Once in the hallway, with no one in sight, he walked much faster. When he turned a corner he saw a familiar figure hobbling ahead of him and he hurried to catch up.

"Dr. Toledano," he called out, and the old man looked about, then stopped to wait for him.

"A mission," he said as Jan came up, speaking the language of their home world rather than the usual Inter. He smiled, his dark, wrinkled features very much like a withered plum. Jan put his hand out without thinking, and the older doctor seized it with both of his. Toledano was a tiny man, barely coming up to Jan's chest, but there was an air of surety about him that denied his size.

"I am taking this one out," he said. "Perhaps my last one. I have had enough field work. I want you as my assistant. Three other doctors, all senior to you. You won't have any freedom or command. But you will learn. Agreed?"

"I couldn't ask for more, Doctor."

"Agreed then." Dr. Toledano withdrew his hands and the smile. The air of friendliness was gone, wiped away in an instant. "It will be hard work and you will get little credit for it. But you will learn."

"That's all I want, Doctor."

The friendship was also gone, packed away in its right place until the time when it could be taken out again. They were from the same planet, they had friends in common. This had absolutely nothing to do with their professional relationship. Walking one step to the rear, Jan followed Toledano into Briefing Central where the other doctors were already waiting. They stood when the senior doctor entered.

"Take your seats, please. I believe that there is one introduction that must be made. This gentleman is Dr. Dacosta, who is a recent arrival. He is beginning his training for a permanent staff position in EPC. Since he is a qualified physician he will accompany us on this mission as my personal assistant, responsible to me and outside of the regular chain of command." Then the others were introduced, one at a time. "Dr. Dacosta, I want you to know that these are the important people. The entire mission is designed to get these specialists to the new planet safely so they can do their surveys. I begin with the lady, Dr. Bucuros, our microbiologist."

She nodded briefly, gray-haired and square-faced, her fingers tapping lightly on the tabletop. She wanted to get on with the work.

"Dr. Oglasiti, virologist. You undoubtedly know his work and must have used his text in school."

The olive-skinned man smiled quickly and warmly, a brief flash of even white teeth. The tall, blond, almost albino man sitting next to him nodded when he was introduced in turn.

"And Dr. Pidik, epidemiologist. The one we hope will have no work to do at all."

All of them, except the still grim Dr. Bucuros, smiled at this sally, though the good humor faded instantly when Toledano opened the folder of papers on the table before him. He sat at the head of the conference table, next to the transparent wall that divided the room in two.

"This is going to be a long session," Toledano said. "We have a no-contact that the techs say approaches a thousand years." He waited, frowning slightly, until the hum of excitement had passed. "This is something of a record so we are going to have to prepare for almost any contingency. I want you to hear the scout's report. We have little more than that to go on." He pressed one of the controls on the table before him.

A door opened on the far side of the dividing wall and a man walked in slowly and sat in the chair next to the barrier, just a few feet away from them. He wore the green of an MT scout, although his collar was open and white bandages could be seen inside. His right arm was in a sling. He looked very tired.

"I am Dr. Toledano in charge of the mission. These are the doctors on my team. We would like to hear your report."

"Scout Starke, Senior Grade."

They heard his words clearly, the concealed microphones and loudspeakers took care of that. This movement of electrons was the only connection between the two sides of the room — between the two separate and completely self-contained parts of the EPC Center. Starke was no longer biologically uncontaminated so he was now in quarantine in beta section, the "dirty" side of the center. The clean, the alpha side, was as biologically sterile as was possible.

"Scout Starke," Dr. Toledano said, looking at a sheaf of papers in his hand, "I want you to tell us what happened to you personally, on this planet. The instrumentation report reveals that the planet is habitable, oxygen, temperature, pollutants all within the normal range of adaptability. Can you add anything to that? I understand the transmatter was activated using the new Y-rider reversal effect?"

"Yes, sir. There have been less than a dozen transmatters activated in this way. The process is expensive and very delicate. All of the other transmatters were either on the league planets or in uninhabitable locations—"

"Pardon me," Jan interrupted, then hurried on, very aware of the sudden attention of the others. "I'm afraid I don't know anything about this Y-rider reversal effect."

"It is in your briefing manual," Dr. Toledano said, his voice emotionless. "In the fine print in the rear. You should have seen it. It is a technique by which contact can be established with a transmatter even if its controls are turned off or useless."

Jan looked at his hands, aware that the others were smiling at him and not wanting to see their faces. He had meant to read all the technical reports, but there had been so little time.

"Please continue, Scout."

"Yes, sir. The transmatter was activated and showed adequate pressure, temperature, and gravity on the other side. So I went through. First contact is always made as quickly as possible after activation. A bleak landscape, cold — my impressions are in the report — felt like winter. No one in sight. The transmatter was half buried. Looked as though it had been covered at one time. I dug down to the controls and saw that they had been blasted away."

"You are sure of that?"

"Positive. Typical explosive flanges. There are photographs. I was attaching a new control unit when I was shot with an arrow. I withdrew. I saw no one and have no idea who shot me."

Further questioning elicited no more information from the scout and he was dismissed. Toledano put a block of plastic down before them into which was sealed the unsterile arrow. They examined it with interest.

"Doesn't seem quite right," Oglasiti said. "The wrong length perhaps, too short."

"You are perfectly correct," Toledano said, tapping one of the papers on the table before him. "The historical section agrees that it was not fired from the normal flexed bow we are familiar with from sporting events, but from an ancient variant called a crossbow There are diagrams here and details of the construction and operation. This form of arrow is called a quarrel. It is well made and finished and carefully balanced. The head is made of cast iron. In their opinion, if this reflects the most advanced artifacts on the planet, the culture is early iron age."

"Retrogrades!"

"Correct. Examination of the photographs reveals that the transmatter is at least a thousand years old, one of the original planet-openers. Considering the level of the culture we can assume that this is the only transmatter on the planet and that they have been out of communication with the rest of the galaxy since soon after the settlement. They are retrogrades. Their culture has slid back to whatever level they were capable of sustaining themselves. We may never find out why the transmatter controls were destroyed, and that becomes academic at this point. Those thousand years of no-contact are our biggest concern."

"Mutation, adaptation, and variation," Dr. Bucuros said, speaking for all of them.

"That is our problem. There are people alive on this planet, which means they have adapted successfully. There will have been local diseases and infections which they have survived and have resistance to, which we might find deadly. They may have no resistance at all to diseases we find commonplace. Gentlemen — and Dr. Bucuros — at this point I will make my set speech about the history of the EPC. We are so used to the initials that we tend to forget that they stand for Emergency Plague Control. This organization was founded in an emergency and exists to prevent another emergency. The plague years came roughly two hundred years after the widespread use of matter transmission. Some attempts to control the spread of disease had always been made, but they were not adequate. Because of the basic differences in planetary metabolism and philogeny almost no diseases were found that could affect mankind. But our own viruses and bacilli mutated in the very different environments they were exposed to and this proved to be the big danger. At first there were disease pockets that quickly grew to plagues. Entire populations were wiped out. The EPC was formed to combat this danger, with all planetary governments contributing equally to its support. After the control of the plagues, and the terrible losses incurred, the EPC was continued as being essential in preventing another outbreak. There are permanent members, like myself and Dr. Dacosta, and assigned specialists, like yourselves, who serve a tour of duty with us. We are involved in prevention, and will do anything to prevent a recurrence of the plague years. I stress the word anything because I mean anything. We are plague preventers first, physicians second. We protect the galaxy, not a single individual or planet. This retrograde planet poses — potentially — the biggest threat I have known during my entire career. We must see to it that it stays just a threat, nothing more than that.

"I will now outline my arrangements for the operation."

It was an hour before dawn when the light tank erupted from the transmatter screen. The treads tore at the hard soil and its transmission whined loudly in the silence. At apparently foolhardy speed it roared across the rutted ground in absolute darkness, heading toward the nearest high piece of ground.

The driver sat calmly at the controls, his face pressed to the optical headpiece. Infrared headlights washed the terrain ahead with invisible radiation — clearly visible to him through the lenses. When he topped the rise he spun the tank in a circle, examining the area all around him, before turning off the engines.

"All clear visibly. You can put up the detector now."

His companion nodded and actuated the controls. A heat shield unfolded on top of the tank — to cancel out the radiation from the tank below — and the scanning head began to rotate. The operator watched the display on the screen before him for a moment before switching on the radio.

"Positioned on highest point two hundred meters from screen. Detector now operating. Numerous small heat sources undoubtedly local animal life. Two larger sources, estimated distance ninety-five meters, now moving away from this position. Large animals or human beings. Since they remain close together and seem to be traveling in a direct line estimate they are human. No other sources within range. End transmission."

A second tank had emerged from the screen and was stationed in front of it. It relayed the message to the waiting convoy, then moved aside as they emerged.

They made an impressive sight. Fourteen vehicles in all — scout tanks, armored troop carriers, supply trucks, trailers. Their large headlights cut burning arcs across the landscape, and as each one emerged the roar of motors and transmissions grew louder. The command car pulled up next to the scout tank and Dr. Toledano stood on a specially elevated step to survey the landscape. There was a growing band of light on one horizon, what they would now call the east.

"Anything more on the detector?" he asked Jan, who sat below operating the radio liaison.

"Negative. The first two blips have moved off the screen."

"Then we'll hold here until it gets light. Keep the detector going and keep everyone alert. When we can drive without lights we'll move out in the direction those blips took."

It was a short wait. Dawn came with surprising suddenness — they must be near the equator — and the first rays of reddish sunlight threw long shadows across the landscape.

"Move out," Toledano ordered. "Single column, guide on me. Scouts out on both flanks and point. I want some prisoners. Use gas, I don't want any casual ties."

Jan Dacosta relayed the message evenly, though he felt certain internal misgivings. He was a doctor, a physician, and the role he was playing now felt more than a little strange. The operation seemed more military than medical so far. He shrugged aside his doubts. Toledano knew what he was doing. The best thing that he could do was watch and learn.

The convoy moved out. Within a few minutes the scout tank on point reported habitation ahead and halted until the others caught up. Jan joined Toledano in the open turret when they stopped on the ridge above the valley, next to the scout tank.

"It's like something out of a history book," Jan said.

"Very rare. The cultural anthropologists and technological historians will have a field day here once we open the planet up."

Morning mist still lay in the valley below, drifting up from the river that snaked by in a slow curve. Plowed fields surrounded a village, a small town really, that huddled on the riverbank. Roofs could be seen, jammed closely together, with the thin ribbons of smoke rising up from the morning fires. The houses were pressed close together because the entire settlement was surrounded by a high stone wall, complete with towers, arrow slits, a sealed gate — and all encompassed by a water-filled moat. Not a soul was in sight and if it had not been for the streamers of smoke it could have been a city of the dead.

"Locked up and sealed," Jan said. "They must have heard us coming."

"It would have taken a deaf man not to."

The radio beeped and Jan answered it. "One of the flankers, Doctor. They have a prisoner.

"Fine. Get him here."

The tank rumbled up brief minutes later and the prisoner was handed down, strapped to an evacuation stretcher. The circle of waiting doctors looked on with unconcealed interest as the stretcher was placed on the ground before them.

The man appeared to be in his middle fifties, gray-bearded and lank-haired. He lay with his mouth open, snoring deeply, rendered instantly unconscious by the sleepgas capsules. The few teeth visible were blackened stumps. His clothing consisted of a heavy, sleeveless leather poncho, worn over roughspun woolen breeks and shirt. The thick leather, knee-high boots had wooden soles fastened to them. Neither clothing nor boots were very clean and there was ingrained dirt in the creases of his limp hands.

"Obtain your specimens before we waken him," Toledano ordered, and the technicians carried over the equipment.

The doctors were efficient and quick. Blood samples were taken, at least a half litre, as well as skin scrapings, hair and nail cuttings, sputum samples, and, after a great deal of working at the thick clothing, a spinal tap. More specimens for biopsy would be obtained later, but this would be a good beginning. Dr. Bucuros exclaimed happily as she routed out and captured some body lice.

"Excellent," Toledano said as the scientists hurried off to their laboratories. "Now wake him up and get the language technician to work. We can't do a thing until we can communicate with these people."

Burly soldiers stood by as the prisoner was awakened. Seconds after the injection his eyes fluttered and opened; he looked about in stark terror.

"Easy, easy," the language specialist said, holding out his microphone and adjusting the phone in his ear. Trailing cables led from these, and from the control box on his waist, to the computer trailer. He smiled and squatted down next to the prisoner, who was now sitting up and searching wildly in all directions for some avenue of escape.

"Talk, speak, parla, taller, mluviti, beszelni—"

"Jaungoiko!" the man shouted, starting to rise. One of the soldiers pressed him back to the stretcher. "Diabru," he moaned, covering his eyes with his hands and rocking back and forth.

"Very good," the specialist said. "I have a tentative identification already. All languages fit into different linguistic families, and every word of every language and dialect is in the computer's memory banks. It needs just a few words to identify cognates and group, then it narrows down even more by supplying key words. Here comes one now." He mouthed the sounds to himself, then spoke aloud.

"Nor?"

"Zer?" The prisoner answered, uncovering his eyes.

"Nor… zu… itz egin."

The process continued rapidly after that. The more words the prisoner spoke the more referents the computer had. Once the language group was known it had this stock of roots to draw on and then proceeded to determine the variations from the norm. Within a half an hour the specialist stood up and brushed off his knees.

"Communication established, sir. Have you used this unit before?"

"The Mark-IV," Toledano said.

"This is the sixth. There have been improvements but not any operating changes. Just press the activate button on the mike when you want a translation. The computer will speak to the prisoner in his own language. Anything he says at all will be translated for you."

Toledano put on the earphone while the soldiers hung the microphone about the prisoner's neck and positioned the loudspeaker before him.

"What is your name?" Toledano asked. A fraction of a second after he spoke, his translated question sounded from the speaker in front of the prisoner, who gaped at it in a blend of confusion and horror. Toledano repeated the question.

"Txakur," the man finally stammered.

"And the name of the town over there?"

The questioning progressed in fits and starts. Some questions the man could or would not answer, either through lack of knowledge or imperfect translation. The former was probably true since the computer perfected its knowledge of the language with every phrase the man spoke. Toledano seemed satisfied with the results in any case.

"The military move out in fifteen minutes," he told Jan. "But I want one squad to stay behind to protect the ancillary units. Would you tell the doctors I want to see them now."

They straggled up one by one, not happy about being taken away from their tests, but knowing better than to make any protests. Toledano waited until they were all assembled before he began.

"We have obtained some knowledge from the in formant. The town over there is named Uri, as is the land about here. I imagine it is a city-state, a primitive political unit. There is another city or country called Gudaegin which seems to be in control of Uri right now. I am guessing that they have been invaded and occupied. We will find out soon enough. The Gudaegin are very warlike, the informant seems very afraid of them, and they have weapons of many kinds. They know that we are here. A warning was sent out to come to the city, and our informant was on the way there when he was captured. I am going to enter the city now and talk to the leaders. I will call you to join us when they are pacified. Meanwhile continue with your work since I will want at least preliminary reports by this evening."

The small convoy moved off behind the command car. A rutted farm track snaked through the fields and they followed that to the brink of the moat. Two rows of piles reached from the shore to the heavy sealed gate in the town wall.

"Annoying," Toledano said, looking through the tank's periscope. "They have taken up the flooring of the causeway. We are going to have to find another way in."

Something hit the water before them, sending up a spout of water. An instant later there was a shattering clang on the tank's deck armor. Through a gunnery slit Jan had a quick glimpse of a black object dropping heavily to the ground.

"It looks like a large stone, sir."

"It does indeed. A powerful launcher of some kind. Zeroed in well. We shall have to take precautions. We will pull back fifty meters and spread out in line. Divide their fire. Then see what kind of a bottom this channel has."

It was mud, soft mud. The fire died as they pulled hack, then concentrated on the single troop carrier that rumbled back to the moat, over the edge, and down into it. The tank was completely watertight, although it never submerged all the way. But when it was only a third of the way across it stuck, treads churning uselessly, sinking deeper. Toledano had foresightedly had a heavy cable fixed to a cleat in the vehicle's rear, so it was dragged unceremoniously backward to solid ground. Small figures were visible on the wall above jumping and waving their hands.

"Enough experimentation," Toledano said. "All vehicles forward to the water's edge. Someone will have to get hurt now and I would prefer it not be us. Hook this circuit through to the computer."

"Couldn't we use sleepgas?" Jan asked. "Men in suits could swim over there and secure the place, open the gate."

"We could. But we would have casualties. We cannot saturate that place with enough gas to knock them all out without overdosing and killing a good number of them. They will have to surrender." He spoke into the microphone and his translated words boomed from the loudspeaker on the hull.

"I talk to the Gudaegin in the city of Uri. We do not wish to harm anyone. We wish to talk to you. We wish to be friends."

More rocks crashed down on the row of armored vehicles and a thick, two-meter long spear buried it self in the ground next to the tank.

"Their answer is clear enough. In their position I would probably do the same thing myself. Now let us see if we can change their minds." He switched on the microphone. "For your own safety I ask you not to resist our entering the city. We will destroy you if we must. I ask you to leave the turret above the gate. The high turret above the gateway. Leave it now. The turret will now be destroyed to show you the power of our weapons."

Toledano waited a few moments then issued orders to the heavy tank. "One round, high explosive. I want it taken off with the first shot. Fire."

It was massive overkill. The turret and a great bite of wall vanished in the explosion. Pieces of masonry — and bodies — wheeled high and splashed into the moat. Jan's fists were clenched, his nails digging into his palms.

"Good God, sir. Those were people. Men. You've killed them — " He choked into silence as Dr. Toledano turned and looked at him in cold anger. The translator was switched on again.

"You will now open the gate and permit us to enter. You will wave a white flag as a symbol of your agreement. If you do not the gate will be destroyed as was the turret."

The answer was a concentration of fire on the command car. Rocks slammed into it, numbing their ears and bouncing the armored car on its springs. The large metal-tipped spears clanged off its hull and a sudden thicket of their slim trunks sprang up around the car.

"Use your light cannon, gunner. I don't want the whole thing down in rubble. Just blow open the gate."

The gun fired, round after slow round. Chewing away the iron-bound planks, dropping them into wreckage and destroying the wreckage.

"There is something happening, sir—"

"Cease fire."

"There, look, on the wall! They are milling about, seem to be fighting with each other."

It was true. First one body, then another, cartwheeled down from the wall to splash into the moat. A few moments later a length of gray cloth — it might generously be considered off-white — unrolled down the wall from the parapet above.

"Battle over," Toledano said, with no satisfaction. "They will rebuild the causeway so we can drive in, protected. I want no more deaths."

His name was Jostun and the computer translated his title as either village elder or council member. He was middle-aged and fat, but the sword he held was bloody. He stood in the middle of the rubble-filled square and waved its point at the building on the other side.

"Destroy it," he shouted. "With your explosions. Bring it down. The Gudaegin will die and the fiend of all of them, Azpi-oyal will die. You are our saviours. Do it!"

"No." Dr. Toledano snapped the answer, a flat, hard statement, understandable even before the computer could translate it. He stood alone, facing Jostun, so small he only came up to the other man's chest. But his command was undeniable. "You will join the others on the far side of the square. You will do it now."

"But we fought them for you. Helped you to win the city. We attacked the invaders by surprise and killed many of them. The survivors cower there. Kill—"

"The killing is over. This is now a time of peace. Go."

Jostun raised his hands to the sky, seeking a justice there that was being denied him here. Then he saw the waiting tanks again and he slumped, the sword dropping from his fingers and ringing on the flags. He went to the others. Toledano turned up the power on the amplifier and faced the sealed building.

"You have nothing to fear from me. Or from the people of this city. You know that I can destroy you in there. Now I ask you to come out and surrender and you have my promise you will not be harmed. Come out now."

As if to punctuate his words the large tank grated in a half circle on locked tread to point the gaping muzzle of its gun at the building. There was silence then, even the people of Uri were hushed and expectant, and the front door of the building squealed and opened. A man stepped out, tall, haughty, and alone. He wore a shining breastplate and helm, a sword held loosely at his side.

"Azpi-oyal!" a woman screamed, and the crowd stirred. Someone pushed through, leveling a taut cross bow. But the soldiers were ready. Gas grenades burst about the bowman and hid him from view. The bolt from the crossbow hurtled out, badly aimed, clattering from the stones of the square and slithering across almost to Azpi-oyal's feet. He ignored it and walked forward. The crowd moved back. He came up to Toledano, a muscular, dark-skinned man with a great black beard. Under the edge of his helm his eyes were cold.

"Give me your sword," Toledano said.

"Why? What will you do with me and my men? We may still die with honor like Gudaegin."

"You have no need to. No one will be harmed. Any who wish to leave may. We have made peace here and we will keep the peace."

"This was my city. When you attacked, these animals rebelled and took it from me. Will you return it to me?"

Toledano smiled coldly, admiring the man's hard nerve.

"I will not. It was not yours in the first place. It has now been returned to the people who live here."

"Where do you come from, little man, and what are you doing here? Do you dispute the right of the Gudaegin to the three continents? If you do you will never rest until you have killed us all. This city is one thing, our land is another."

"I want nothing that you have. Your lands or your fortunes. Nothing. We are here to make the sick well. We are here to show you how to contact other places, other worlds. We are here to change things, but only to make them better. Nothing that you value will be changed in any way."

Azpi-oyal weighed his sword in his hand and thought. He was not a stupid man. "We value the strength of our arms and our people. We mean to rule on the three continents. Will you take away our conquests?"

"Your past ones, no. But you will have no future ones. We cure disease and your kind of killing can be a disease. You will have to give it up. You will soon find that you do not miss it. As a first step on that road you will give me your sword." Toledano put out his tiny, almost child-size hand.

Azpi-oyal stepped back in anger, clutching the pommel. The turret on a tank squealed as it turned to follow him. He looked with hatred at the lowered muzzles of the guns — then burst out laughing. Tossing the sword into the air he caught it by the point and extended it to Toledano.

"I don't know whether to believe you or not, small conqueror. But I think I would like to live a little longer to see what you are going to do to the three continents. A man may always die."

The worst was over. Politically at least. They would now have a period of relative peace during which the tests and examinations could be made. A thousand years of isolation was a long time.

"We must get started," Toledano said, with sudden irritation, as he waved the radio operator to him. "Enough time has been wasted. Have the other units move up. We'll set up a base in this square here."

"The line is longer if anything," Jan said, looking out of the window. "Must be a hundred or more. It looks like the word has finally gotten out that we aren't doing terrible things to the citizens here, but are actually curing some of their ills."

They had occupied a large warehouse near the main gate and a medical aid station had been set up. There had been few volunteers for their glittering and exotic instruments at first, but they had enough involuntary patients among the wounded survivors of the fighting. Most of these had already been given up for dead. The crude local knowledge of medicine did not appear to go beyond bone setting, suturing of simple wounds, and amputation. The notion of antisepsis had stayed with them through the lost centuries, and they used alcohol as an antiseptic and boiled the bandages and instruments. But they had no way of treating infections — other than by amputation — so that death was the usual result of any deep, puncturing wound. The doctors had changed all that. None of their patients died. They healed abdominal wounds, repaired shattered limbs and heads, cured gangrene and other major infections, and even sewed back on a severed arm. This last seemed more miraculous than medical and soon the townspeople were flocking for treatment with almost religious enthusiasm.

"The waste, the absolute waste," Dr. Pidik said, giving the patient before him, a frightened girl, an injection of fungicide. "War first, that's where all the talent and energy goes, with medical care lagging ages behind. They have engineers, mechanics, builders. Did you see those steam ballistae? A pressure tank and miles of pipe and those piston-actuated things that dropped rocks right down the exhaust pipes of the tanks. You might think they could spare a miniscule amount of energy for some work on the healing arts."

The tall epidemiologist bent his blond head low, carefully cutting away dead tissue and swabbing out the wounds on the girl's monstrously swollen foot. It was twice its normal size, dark, knobby, decayed. There was no pain, the local anaesthetic took care of that, yet she was still terrified at what was happening.

"I've never seen anything like that at all," Jan said. "I don't believe there is even a reference in our text books."

"This is one of the diseases of neglect; you'll find it mentioned in the older texts. You'll see many things like this in the backwaters of the galaxy. It's maduromycosis. There is first a penetrating wound, common enough, that plants fungus spores deep inside the flesh. If untreated this is the result after a course of years."

"I've seen this, though," Jan said, taking the hand of the blank-eyed man who had been led before him. He rotated the man's hand in a circle, then let go of it. The rotation of the hand continued, automatically, as though a machine had been set into motion. "Echo-praxis, meaningless repetition of motions once they are started."

Pidik looked up and snorted. "Yes, I imagine you have seen it. But you found it in the mental wards, a condition of paranoia. I'm willing to bet this is from physical causes, untreated cranial fracture or some such."

"No bets," Jan said, touching lightly the heavily depressed area in the man's skull. It was surrounded by scar tissue and obviously an old wound.

They had a little of everything. Infections, sores, diseases, chronic illnesses, carcinomas. Everything. It was nearly dusk when Pidik called a halt.

"Almost twelve standard hours at this. Enough. They can come back tomorrow. This planet has too long a period of rotation and it takes some getting used to."

Jan repeated the order through the computer and, after not too many complaints, the patients allowed themselves to be pushed out by the guards. All but the sickest stayed in their positions in line, huddling against the wall, to be treated the following day. Jan joined Pidik at the sink where he was washing up.

"I can't thank you too much, Dr. Pidik. Since you have been helping me I think we have seen ten times as many patients. There are so many things here I know nothing about. There really should be a medical school for EPC physicians."

"There is. Right here in the field. You have had good training. There is nothing here you can't treat after some experience. And Dr. Toledano will see that you get it."

"Isn't this taking you from your work?"

"This is my work. An epidemiologist is no good without an epidemic. I've looked at all the samples and seen the various kinds of wildlife these people carry in their bloodstreams. Nothing exotic so far, nothing alien.

Just a good selection of the bacilli and viruses and such that have dwelt in mankind since the beginning of time. Here in the field I may see something that we have missed in the labs." Jan shook the water from his hands and took a towel. "We've been here almost a month," he said. "If there were any exotic infections wouldn't we have turned them up by now?"

"Not necessarily. We've only been looking at one corner of an entire world. Once our in-depth study is made here we can do a more general survey of the rest of the planet. When it has been cleared for contact the politicians and the traders will come through."

"Do you believe Azpi-oyal's story that an entire army of Gudaegin is on the way?"

"Absolutely. His people seem to have conquered almost all of the other groups on this planet. They won't stand for us taking away one of their cities. But Dr. Toledano will be able to handle them—"

"Some kind of a riot developing, Doctors," a sergeant said, poking his head into the room. "And it seems to be about some kind of sickness. Could we have your help?"

"I'll come," Jan said, swinging the communicator to his shoulder.

"So will I," Pidik said. "I don't like the sound of this."

A squad of soldiers was waiting for them outside, weapons at the port The sergeant led. Before they had gone more than a few paces they could hear the distant roar of voices. As they came closer individual screams and cries rose above the continual shouting, and then the thud of exploding gas grenades. They double-timed the rest of the way.

Only the guns of the soldiers and the waiting tank kept the hysterical mob from attacking. A huddle of unconscious bodies proved that even this had not been enough. As they pushed through to the line of defenders in front of the building, Dr. Pidik waved the sergeant to him.

"The computer can't make any sense out of this noise. Grab someone who looks like a spokesman and get him over here."

There was a sudden bustle of action and the sergeant reappeared, half dragging a burly citizen of Uri who was still a little dazed by the sergeant's efficient means of argument. He was a tall man with a broad chest, sporting a scraggle of beard and a patch over one eye. The other, red and malevolent, peered from beneath a jutting brow ridge.

"What is wrong? Why are you all here?" Pidik asked the man through the computer's translation unit.

"The plague! They have the plague in there. Burn down the house and kill all in it. That's what you do with the plague. Death cures!"

"It's the final cure," Pidik said calmly. "But let us see if there aren't other not quite so drastic measures that we can use first. Come on," he said to Jan, and started up the stairs toward the house.

A moan rose up when the crowd saw what they were doing, followed by an even more intense howl of anger. Despite the guards the mob pressed forward.

"Use gas if you must," Pidik ordered. "But stop them right here."

Clouds of vapor sprung up as he hammered on the door and called through the translator for them to open it. It remained sealed and silent.

"Open this," Pidik ordered the nearest soldier.

The man eyed the tall door and noticed the bolt heads for the hinges on one side. He pressed small explosive charges over these spots, close to the frame, pushed in timers, and stepped back.

"Ten seconds, sir. They're shaped charges, punch right through, but there can be a certain amount of reverse blast."

They hugged the wall as the sharp crack of the double explosion sounded. The crowd wailed. The two doctors climbed over the ruined door and followed the sound of running feet through a dark hallway. At the end, with the last rays of sunlight filtering through a high, barred window, they found a man lying in bed. A huddle of women and children were pressed silently into the corner.

"Corporal," Pidik said to the soldier who had followed them in. "Get these people out of here. See that no one else enters the building. Call Dr. Toledano for more aid if you need it."

"We'll hold them fine, sir, not to worry."

"Very good. Give me your light then before you go."

The intense beam shot out and the man on the bed moaned, turning his head away and shielding his eyes with his arm. The inside of his forearm was swollen and red, covered with tiny pustules. Dr. Pidik took the man's hand, frowning as he felt the fever-heat of the skin, and gently pulled his arm away from his face. The man's features were also red and swollen, his eyes almost closed, and at first they did not recognize him.

"It's Jostun," Jan said. "The council leader."

"Izuri..." Jostun muttered, thrashing back and forth on the pillow.

"Plague," Pidik said. "That word is clear enough. Get an ambulance here at once and pass word that I want to use the isolation ward. And tell Dr. Toledano what is happening so he can alert the troops."

Jostun called out to them, and Pidik held out the translator microphone.

"Leave me… burn the building… I am dead. It is the plague."

"We are going to take care of you—"

"Death alone cures the plague!" Jostun shouted, half rising as he did so, then falling back heavily, moaning with the effort.

"They all seem pretty convinced of that," Jan said.

"Well I'm not. A disease is a disease — and has a cure. Now let's get him moved."

The city was in a panic. The ambulance had to drive slowly through the dark streets to avoid running over the limp bodies that were strewn on all sides. Sleepgas was being used in greater and greater quantities by the outnumbered soldiers. The encampment in the square was a besieged lager whose defenders opened a gate in the perimeter to admit the ambulance.

"What is the disease?" Toledano said, appearing as the stretcher was carried into the hospital.

"I am sure that I don't know yet, Doctor. I will inform you when I do."

"I suggest it be quick. We have seven other cases already."

Pidik turned away without another word and Toledano beckoned to Jan. "Come with me." He started at a fast walk toward his headquarters prefab with Jan hurrying after him. They reached it just as a troop carrier slid to a stop and an officer jumped down.

"Bad news, sir. One of the wall positions was attacked, both men dead. The alarm went off and we fought our way back there, but…" He hesitated. "We think they got someone over the wall. This is the man who was in charge."

A limp figure was carried out and dropped, not too gently, at their feet. Toledano looked at the slack features and grunted. "Azpi-oyal; I might have known. Bring him into my office. Jan, wake him up."

Inside, in the brilliantly lit room, the reddish flush on Azpi-oyal's skin was clearly seen, and when Jan gave him the injection the skin was hot to his touch.

"I'm afraid that he has it too, sir," Jan said.

Azpi-oyal blinked back to consciousness, straightened up and smiled. There was no trace of warmth in the smile.

"My messenger has gone," he said into the translator. "You will not be able to stop him."

"I would not want to. I see no reason why you should not contact your own people. Your army must not be more than a day's march away."

Azpi-oyal started slightly at this mention. "Since you know about the Gudaegin, fifty thousand strong, you will know that you are lost. I have sent them the message to come here, and to destroy this city and all who dwell within it. Now tell me that you would have permitted that message to be sent?"

"Of course I would." Toledano said calmly. "This will not be done. The city will stand and all will live."

"The plague sufferers — like myself — will be killed. The plague bearers, yourselves, will be destroyed."

"Not at all." Toledano sat down and put the back of his hand to his mouth while he yawned. "We did not bring the plague. But we shall destroy the plague and cure all who suffer from it. You will now be taken to a place where you can rest." He called the guards and switched off the translator. He still spoke calmly, but there was an urgency now to the meaning of his words.

"Take this man to the hospital and see that he is well treated but under constant guard. Use as many men as necessary. He is not to be left unwatched at any time nor is he to escape. This is vital. Do you understand?"

"Yes, sir."

"Might I ask what is happening?" Jan said when they had gone.

"Scouts reported this Gudaegin army a few hours ago. They must not like our taking away one of their captured cities. I hoped to use Azpi-oyal to make peace with them. I still shall, if we can find a cure for this plague."

"What was this nonsense about our bringing the plague?"

"No nonsense. It looks like the truth, though I don't see how it can be. Allowing for minor variations due to incubation period, the only people who are getting sick are the ones who had first contact with us. There is no way of escaping that fact."

Jan was shocked. "It just can't be that way, sir! The only microscopic life we carry in our systems is intestinal flora. Which is harmless. Our equipment is sterile. It is impossible that we could be involved."

"Yet we are. We must now find out how—"

Dr. Pidik burst through the door and dropped a slide on the desk. "There's your culprit," he announced. "A coccobacillary microorganism. It takes an aniline stain and is gram-negative."

"You sound like you are describing a rickettsia?" Toledano said.

"I am. Their blood is teaming with the beasts."

"Typhus?" Jan asked.

"Very much like it. A mutated strain perhaps. And I thought they were immune. We found traces of an organism like this in a number of the blood samples we took. Yet the individuals were healthy. They aren't any more."

Toledano paced back and forth the length of the small room. "It does not make sense," he said. "Typhus and all the related diseases are vectored by insects, mites, body lice. I have complaints about the EPC, but we couldn't have been involved in that way. But there still appears to be a connection. Perhaps in the country through which we drove, we might have picked up something on the way. Yet there has been no sickness among our personnel. We will have to look into this. But getting a cure comes first, top priority. Cure them first and we'll find the source later."

"I have an idea about that — " Jan said, but broke off at the sound of a distant splintering crash followed by screams and shouting. At the same moment the duty lieutenant ran in.

"We're under fire, sir. Steam ballistae, bigger than anything in the city. They must have moved them up as soon as it became dark."

"Can we knock them out without hurting anyone?"

"Negative, sir. They are out of range of gas weapons. We could—"

He never finished the sentence. A crashing roar hammered at their ears, stunning them, and all the lights went out. The floor buckled and Jan found him self hurled down. As he climbed to his feet the beam of the lieutenant's light cut a dust-filled path through the darkness, moved across the sprawled forms, and came to rest on the rough slab of stone that had crashed down upon them.

"Dr. Toledano!" someone shouted, and the light came to rest, flickering erratically as though the hand that held it were shaking.

"Nothing, no hope," Pidik said, bending over the small huddled form. "It took half his head away. Dead instantly." He stood and sighed. "I have to get back to the laboratory. I imagine this means you will be taking over, Dr. Dacosta."

He was almost to the entrance before Jan could gather his wits and call after him. "Wait, what do you mean?"

"Just that. You were his assistant. You are career EPC. The rest of us have other things to do."

"He never intended

"He never intended to die. He was my friend. Do the sort of job he would have wanted you to do." Then he was gone.

It was too much to accept all at once, but Jan forced himself to act. The chain of command could be straightened out later. Now it was an emergency.

"Have Dr. Toledano's body removed to the hospital," he ordered the lieutenant, and waited until the command had been passed on. "I recall the last thing you said was something about their being out of the range of gas, the things that are firing at us?"

"Yes, sir, they're beyond a ridge of hills."

"Can we locate them exactly?"

"We can. We have artillery spotters, infrared, camera equipped, miniature copters."

"Send one out. Get the location and range of the emplacement, look for the steam generator. If this weapon is like the ones on the walls — it should be, only bigger — there will be one generator and pipes to the ballistae. Locate this and, with one gun firing, what do you call it…?"

"Ranging in?"

"Exactly. When you have the range blow up the generator. That will stop the firing. You'll kill some people, but there are more being killed right here. Including Dr. Toledano."

The officer saluted and left. Jan was suddenly tired and he went to the washroom to put cold water on his face. A brilliant emergency light came on in the room behind him and in the glass over the sink he looked into his own eyes. Had he really issued that order to kill, just like that? He had. For the greater good of course. He looked away from the mirrored eyes and plunged his face into the water.

Dawn was only a few hours away and most of those present had the drawn looks of near exhaustion. The ceiling of the office had been patched, a new desk brought in, all signs of damage removed. Jan sat behind the desk, in what had once been Dr. Toledano's chair, and waved the others to seats as they came in.

"It looks like we are all here now," he said. "Dr. Pidik, could you give us the medical situation first?"

"Under control, I'll say that much." The tall epidemiologist rubbed at his unshaven jaw. "We haven't lost any patients yet, supportive treatment seems to be working with even the worst cases. But we can do nothing to stop the spread of the disease. It's absolutely out of control. If it continues at this rate we are going to have everyone in the city sick, we'll have to call in help to handle them. I've never seen anything like this before in my entire life."

"How does it look from the military point of view, Lieutenant?"

The man, near the end of his strength, lifted his hands and almost gave a shrug for an answer, controlling himself only at the last instant. He pulled him self erect. "We are having less trouble from the populace. All of our men are withdrawn from the streets, and either on the walls or guarding the camp here. A lot of people are sick, that takes the fight out of them, the rest seem sort of dazed. The enemy outside has been moving into attacking positions and I think we can expect a heavy attack at any time now, probably at dawn."

"What makes you say that?"

"The equipment they've brought up. More ballistae of all sizes. Steam-powered rams, bridging material, grappling towers. They are ready for a concerted effort and they have the men and equipment for the job."

"Can you stop the attack when it comes?"

"Not for long, sir. We might with the aid of the people in the city, but they are more than useless. We shall have to guard against them as well. There are just not enough of our troops to man the walls. If you will pardon my suggesting it, we are faced with two possible solutions. One, we can call for more troops. The technicians have set up a transmatter and a larger one can be brought through and assembled. Secondly, we can withdraw. Any defense here will be costly of men — on both sides — and equipment. The Gudaegin are tremendous fighters and never stop until they have won."

"If we leave — what happens to the people of the city?"

The lieutenant looked uncomfortable. "It's hard to say, but, I imagine, if they're sick—"

"They will all be killed. I don't think much of that as a solution, Lieutenant. And we can't take them back to base, there isn't room for a cityful of sick people. And there are no other quarantine stations that can handle them. The situation is beginning to look a little grim."

Their silence, their downcast expressions, echoed only agreement. There seemed no simple way out of the situation. A number of people were going to die no matter what they decided. These deaths would be a black mark on the record of the EPC. Perhaps an other training film would be made about their mistakes, warning others not to repeat them.

"We are not beaten yet," Jan told them, when no one else elected to speak. "I have some other plans that may alter the situation. Carry on as you have been doing and by dawn I will let you know. Lieutenant, if you would remain I would like to talk to you."

Jan waited until the others had filed silently out and the door was closed before he spoke. "I want a volunteer, Lieutenant, a good soldier who is a professional fighting man. I am going outside of the city and I am going to need some skilled help—"

"You can't do that, sir! You're in command."

"Since I am in command there is nothing to stop me, is there? The mission I have in mind needs a young and fairly expendable medical man, for which I qualify well. The medical teams do not need me now and you can man the defenses whether I am here or not. If I get into trouble a call to headquarters can send a more highly qualified EPC man through in a few minutes. So there really is no reason why I should not go, is there?"

The lieutenant reluctantly agreed — although he did not like it — and went out in search of a volunteer. Jan was loading equipment into a pack when there was a knock on the door.

"I was told to report to you, sir," the soldier said, saluting. Jan had seen him before, a big man with a neck like a tree trunk, who nevertheless moved quickly as a cat. He was weighted with combat gear and looked ready for anything.

"What's your name?"

"Plendir, private, EPC Guard, sir.

"Weren't you wearing a sergeant's stripes a few days ago?"

"I was, sir, and not for the first time. Field demotion. Drink and fighting. Not our own men, sir. Locals. About fifteen of them jumped me. Most still in hospital, sir."

"I hope you are as good as you say, Plendir. Ready to go with me outside of the city?"

"Yes, sir." His stony expression did not change.

"Good. But it's not as suicidal as it sounds. We're not going over the wall, but we'll exit by the transmatter we used when we first hit this planet. That should put us some miles behind the enemy troops. I want to capture one of them. Do you think it can be done?"

"Sounds like an interesting job, sir," Plendir said, almost smiling at the thought.

Jan slipped on his pack and they went to the tech section. Bright lights flooded the temporary structure and a generator whined steadily in the background, supplying the operating current for the equipment and for recharging the vehicles' high-density batteries. They stepped over cables and walked around equipment to the familiar slab shape of a personnel transmatter screen.

"Has it been checked out?" Jan asked a passing tech.

"To the last decimal place and locked on frequency, sir."

Jan made a note of the transmatter's code on the inside of his wrist, and Plendir automatically did the same. Until they had the call number memorized they did not want to risk being locked out of the city.

"If I might make a suggestion?" Plendir asked, as Jan punched the code for the other transmatter on the keyboard.

"What is it?"

"We are, so to speak, going into my area of operation now. We have no idea of who or what might be waiting on the other side. I go through first and roll left. You come after me as quickly as you can and dive right. Then we are both through and down low and looking things over."

"Just as you say, Plendir. But we are far enough from the enemy troops so I don't think we have to worry."

The soldier raised his eyebrows slightly, but otherwise did not answer. When the operation light came on he waved Jan forward — then dived headfirst at the screen. Jan jumped right after him, ready to hit the ground.

Cold air, black night, a sharp explosion, and something heavy hitting the ground next to him. Jan dropped; harder than he had planned, driving the air from his lungs. By the time he had gasped and lifted his head to look around the brief battle was over. A man lay on the ground near him, slumped and unconscious, and another was near the crouching Plendir, rolling and moaning softly. A cloud of gas, barely visible in the starlight, was drifting away from three other motionless figures. There was a crackling in the brush that lessened and died away.

"All clear, sir. They were on guard here, but I was maybe expecting them and they weren't expecting me. Not just then, if you know what I mean. That one by you may be dead, couldn't help it, me or him. But this one has a broken wing and the others are gassed. Will any of them do?"

"The wounded one will be best, let me look at him." Jan stood and swung off his pack. "Some of them got away, didn't they?"

"Yes, sir. They'll be bringing back their friends. How long will you need?"

"Fifteen minutes should do it. Think we can manage that much?"

"Probably. But I'll give you all the time I can. Need help with him before I take a look around?"

"Yes, just one second."

The prisoner winced away from the harsh light. Outside of his metal helm he did not look very soldierly, dressed in coarse cloth and half-cured furs. He tried to scrabble away when Jan touched his arm, but the sudden appearance of the point of a trench knife just in front of his eyes changed his mind. Jan was quick. He slipped an inflatable cast over the arm, set the bones through the flexible fabric, then triggered the pressure. It blew up with a quick hiss, holding the broken arm rigid and secure.

"He's not going to like what comes next, so could you tie his wrists and ankles together and roll him onto his side."

Plendir did this with quick efficiency while Jan spread out the contents of his pack. He had blunt-tipped surgical shears that he used to cut away the prisoner's clothing. The man began to howl and Jan shut him up with a piece of sticking tape over his mouth.

"I'd like to look about, sir," Plendir said, sniffing the air. "It's going to be dawn soon."

"I'm fine here."

The soldier slipped soundlessly away and Jan balanced the light on a rock while he bared the man's not-too-clean back. There was a muffled moan. From his pack Jan took the thing he put together earlier, a great square made by criss-crossing many lengths of surgical sticking tape. He held the prisoner from moving with his knee while he slapped the square across the man's back. As Jan pressed it into place the man moaned at the cold touch and tried to shiver away. Jan stood, brushing off his knees, and looked at his watch.

Dawn was lightening the east when Plendir reappeared.

"They made good time, sir," he reported. "There must be a camp near here. Anyway a whole gang of them are on the way now."

"How long do we have?"

"Two, maybe three minutes, at the very outside."

Jan looked at his watch. "I need at least three minutes. Can you arrange some kind of holding action?"

"My pleasure," Plendir said, and went. off at a trot.

They were very long minutes, with the second hand of the watch moving as though crawling through molasses. There was still a minute to go when there was the sound of distant explosions and shouts.

"Time enough," Jan said, and bent swiftly to tear off the sticking plaster. He did it with a sudden pull, but it took plenty of hair with it and the prisoner writhed in silent agony. Jan stuffed the square into his pack before permitting himself a quick flash of the light.

"Wonderful!" he shouted.

The man's back had a pattern of square red welts, one bigger than the others and so swollen that it projected like an immense boil from his skin. Plendir came pelting back at a dead run.

"They're right behind me!"

"One second, I need the evidence!"

Jan fumbled out the camera as the soldier spun about and hurled gas grenades back in the direction he had come from. The flash burst out its sudden light and Jan shouted, "Let's go!" Something hissed by his ear.

"Do it — I'm right behind you!"

Jan hit the actuator on the preset controls and jumped into the screen. He hit the floor, skidded and fell as Plendir came diving through behind him in a neat roll. The bolt from a crossbow followed them and thunked into the wall across the room. Plendir hit the controls and the connection was broken.

"The last shot of the war," Jan said, smiling, looking at the quarrel imbedded in the wall. "It should be all over now."

The doctors looked at the blown-up print of the color photograph, then at the square of sticking tape. that had been applied to the man's back.

"It seems obvious now by hindsight," Dr. Bucuros reluctantly admitted, as though she were angry she had not considered the possibility herself.

"Allergy," Dr. Pidik said. "The one thing we never considered. But did you have to be so dramatic about obtaining a subject?"

Jan smiled. "One of the city people might have been all right, but I couldn't be sure. I had to get some one from outside, who had never been in contact with us in any way. The Gudaegin soldier proved ideal as you can see. A reaction to a number of common specimens we have — and one single, massive allergic reaction right there." He tapped the photograph over the swollen red welt.

"What is the allergen?"

"Polyster. Our most common plastic. Our clothes are woven out of it, our belts, equipment parts, numberless things. It would be impossible for them not to come into contact with it. With disastrous results. You gave me the clue, Dr. Pidik, when you said that a lot of the people here seemed to have the inactive plague microorganisms in their bloodstreams. It reminded me of something. Typhus is one of the few diseases that a person can carry, yet still not be ill himself. Apparently the mutated form of typhus on this planet was very deadly. You either died — or were immune. People who came down with the disease were killed. So the present populace is descended from immune — and infected individuals. All of them."

"And our coming triggered it off," Pidik said.

"Unhappily true. There appears to be a relationship between this polyster allergy and their natural immunity. They first experience a massive allergic reaction. This breaks down their bodies' defenses and produces a synergistic reaction with the typhus, weakening their natural immunity. They get sick."

"But not any more," Pidik said, firmly.

"No, not any more. Now that we know the cause we know the cure. And the first one we are going to cure is Azpi-oyal, our ambassador of good will to his fellow Gudaegin. When he is cured he will believe in the cure. He will see the others treated and recovering. And if there are no more plague victims there is no further cause for war. We can deal with them, make peace, and get out of this tight corner we have maneuvered ourselves into."

There was the sound of distant horns and massed shouting.

"I suggest you hurry," Dr. Bucuros said, turning to leave the room. "We are going to have a hard job of convincing them of anything if we are all dead."

In silent agreement they hurried after her.