"What does the oxygen register say?"

"Oxygen register?"

He gritted his teeth against the fever which began to shake his body mercilessly until he wanted to scream to make it stop. He became angry even as the fever shook him: angry not really at the doctors; not really at any one thing. Angry because the mountains did not care if he saw them; angry that the air did not care if he breathed it. Angry because, between planets, between suns, the coldness of space merely waited, not giving a damn.

Several years ago—ten, twenty, perhaps more—some doctor had finally isolated a strain of the filterable virus of liguna fever that could be used as a vaccine: too weak to kill, but strong enough to produce immunity against its more virulent brother strains. That opened up the Sitari System for colonization and exploration and meant that the men who got there first would make fortunes.

So he went to the base at Ke, first selling his strip mine property and disposing of his tools and equipping his spaceship for the intersolar trip; and at Ke they shot him full of the disease. But his bloodstream built no antibodies. The weakened virus settled in his nervous system and there was no way of getting it out. The doctors were very sorry for him, and they assured him it was a one-in-ten-thousand phenomenon. Thereafter, he suffered recurrent paralytic attacks.

If it had not been for the advance warning—a pain at the base of his spine, a moment of violent trembling in his knees—he would have been forced to give up solitary strip mining altogether. As it was, whenever he felt the warning, he had to hurry to the nearest colony and be hospitalized for the duration of the attack. He had had four such warnings on this satellite, and three times he had gone to Pastiville on Helio and been cared for and come away with less money than he had gone with.

His bank credit, once large, had slowly dribbled away, and now he made just about enough from his mining to care for himself during illness. He could not afford to hunt for less dangerous, less isolated work. It would not pay enough, for he knew how to do very little that civilization needed done. He was finally trapped; no longer could he afford a pilot for the long flight from Helio to a newer frontier, and he could not risk the trip alone.

He lay waiting for the new spasm of fever and stared at Hertha who, this time, would care for him here and he would not need to go to a hospital. Perhaps, after a little while, he would be able to save enough to push on, through the awful indifference of space, to some new world where, with luck, there would be a sudden fortune.

Then he could go back to civilization.

He realized bitterly that he was merely telling himself he would go back. He knew there was only one direction he could go, and that direction was not back.

Hertha waited, hurt-eyed, moving her pudgy hands helplessly.

When the shaking subsided, he explained through chattering teeth about the oxygen register across the room, and she went away.

The fever vanished completely, leaving him listless. His hand, lying on the rough blanket, was abnormally white. He wiggled the fingers, but he could not feel the wool.

His mouth was dry and he wanted a drink of water.

Hertha moved out of his range of vision. He shifted his head on the damp pillow and watched her out of the corner of his eye.

He had never heard her real name, but she did not seem to object to his name for her.

He tried to sit up again, but he was very weak. He wanted to quote it to her and tell her what he had never told her: that the name of it was Hertha and that it had been written long ago by a man named Swinburne, and he wanted to explain why he had named her after a poem, because it was very funny.

The harsh light hurt his eyes and made him feel dizzy. He lay watching her as she bent toward the oxygen dial, wrinkling her face in animal concentration, trying to read it for him. Her puzzled expression was pathetic; it reminded him of the first time he had seen her.

The walls began to spin crazily, for the hut had been intended for only one person.

He remembered the first time he saw her, cowering in a filthy alleyway in the Miramus. At first he thought she had taken some food from a garbage pail and was trying to conceal it by holding it to her breast. But when the flare of a rocket leaving the field two blocks away lit the area for a moment, he saw that she was holding a tiny welikin, terribly mangled, looking as if it had just been run over by a heavy transport truck. He took it away from her and threw it into the darkness, shuddering.

"It was dead," he said.

She continued to stare at him, starting to cry silently, big, round, salt tears that she brushed at with reddened hands.

"My—my—" she stammered.

He had an eerie feeling that she was trying to say, "My baby," and he felt a little chill of pity creep up his spine.

"What do you do?" he asked kindly.

"Sweep floors. I work a little for the Commander's wife. Around her home."

"How did you get here?"

Still crying, she said, "On a rocket."

"Of course. What I meant was...." But he did not need to ask how she had gotten passed the emigration officers. Some influential man—such things could happen, especially when the destination was a relatively new frontier, such as Helio, where there was little danger of investigation—had seen to it that certain answers were falsified; and a little money and a corrupt official had conspired to produce a passport which read, "Mentally and physically fit for colonization."

The influential man had, in effect, bought and paid for a personal slave to bring with him to the stars. She would not know of her legal rights. She would be easily frightened and confused. And then something had happened, and for some reason she had been abandoned to shift for herself. Perhaps she had run away.

He looked away from her face. This was none of his affair.

"Never mind," he said. He reached into his pocket and gave her a few coins and then turned and walked rapidly away, suddenly anxious to see the bright, remembered face of the young colonist, Doris, Don's friend; a face that would chase away the memory of this pathetic creature.

After a moment, he heard the pad of her feet hopefully, fearfully following him.

She was standing beside his cot again, and he concentrated to make the walls stop spinning.

"It had a blue line."

"Yes, I know. Where?"

She showed him with her fingers. "This much."

"Halfway up?" he prompted.

Dumbly, she nodded.

He looked at the plants. "Hertha, listen. I've got to talk before the paralysis comes back. You'll have to listen very carefully and try to understand. I'll be all right in about ten days. You know that?"

She nodded again.

He took a deep breath that seemed to catch in his throat. "But you'll have to go outside before then."

Hertha whimpered and fluttered her hands nervously.

"I know you're afraid," he said. "I wouldn't ask you, but it has to be done. I can't go. You can see that, can't you? It has to be done."

"Afraid!"

"Nonsense!" he said harshly. "There's nothing to be afraid of. Put on the outside suit and nothing can hurt you."

Moaning in fear, she shook her head.

"Listen, Hertha! You've got to do it. For me!" He did not like to make the appeal personal. He would have preferred to convince her that fear of the outside was groundless. It was not possible. He had attempted, again and again, to explain that the tiny satellite with its poison air was completely harmless as long as she wore a surface suit. There was no alien life, no possible danger, outside this tiny square of insulated hut and breathable air. But it was useless. And the personal appeal was the only course remaining. It was as much for her sake as his; she also needed oxygen, but she could never understand that fact.

"For you?" she asked.

He nodded, feeling the fever rise. His face twisted in pain, and he stared pleadingly into her cow-like eyes: dumb eyes, animal eyes, brown and trusting and ... loyal. The paralysis struck. His voice would not come up out of his chest and the dizziness swamped his mind, and, in fever, he was once again in Pastiville, the nearest planet with an oxygen atmosphere.

Hertha followed him up the alley, out into the cheap glitter of Windopole Avenue, a rutted, smelly street which was the center of the port-workers' section. She followed him across Windopole, up Venus, across Nineshime. He turned into the Lexo Building, which had become shabby since he had seen it last, when it had been freshly painted. She did not follow him inside, and he breathed a sigh of relief and tried to put her out of his mind as he walked up the stairs to the room 17B.

After a moment's hesitation, his heart knocking with pleasant anticipation, he pressed the buzzer.

"Come in."

He found the knob, twisted open the door, entered.

"Why Jimmy!" the girl said in what seemed to be surprise and heavy delight. She crossed to him quickly and offered her lips to be kissed. "It's good to see you!"

He took half a step backward, trying to keep the shock out of his face.

"Oh, it's so good to see you, Jimmy! Sit down. Tell me all about it, about everything. Did you make loads and loads of money? When did you get back? How's the lig fever?"

He sat down, scarcely listening, studying the apartment, feeling vaguely ill. She was chattering, he realized, to overcome her embarrassment.

"The books you ordered came. I've got them right here. They're all there but some poetry or other. There was a letter about that, but the people just said they didn't have it in stock. I opened it to see if it required an answer. Just a sec. I'll get them for you." She left the room with quick, nervous strides.

The apartment had been redone since he had seen it. There were now expensive drapes at the windows, imported from somewhere; a genuine Earth tapestry hung above the door. Plump silken pillows scattered on the floor and a late model phono-general in the corner, with a gleaming cabinet and record spool accessory box.

She came back with the books, neatly done up in a bundle.

"I guess you still read as much as ever? Don said you always were a great reader."

Uncomfortably, he stood up.

She put the books on a low serving table, moistened her lips to make them glistening red. "Sit down, Jimmy!"

He still stood.

"Jimmy!" she said in mock anger. "Sit down! Goodness, it's good to have a fellow Earthman to talk to. I was so busy when you came by the other time, we scarcely had a minute to talk. I'd just got here, you remember.... Well, I'm settled now, so we'll just have to have a nice, long talk."

He shifted on his feet.

"I don't suppose you've heard from Don?" Her voice was strained, almost desperate. "Isn't it the oddest thing, him knowing you and me, and both of us right here?"

"He told me to write how you were getting along?"

"... Oh."

He smiled without humor and felt like an old man. He wanted to explain how he had looked forward to seeing a person from his own planet again. Now he wanted to remind her of the girl he remembered: When she had just arrived, still unpacking, eager to start as a junior secretary for the League.

"Thank you for letting me send the books here," he said. The sickness was heavy in the pit of his stomach, and suddenly he was hard and bitter. He quoted softly:

"Old poetry? I guess you really do read a—" Then understanding made her eyes wince. "That wasn't intended to be very complimentary, was it, Jimmy?"

Her name was no longer Doris; it was any of a thousand, and her perfume, heavy in his nostrils, was not her perfume or any individual's. She was there before him; she was real. But along with her were a thousand names and a thousand scents. There was the painful nostalgia of recognizing a strange room.

Awkwardly he said, "I really must go. I'd like to have a long talk, but—"

Her lips parting in sudden artificiality, she crossed to him, reached for his hand with her own.

In his mind was the heavy futility of repeating the same thing senselessly until it lost all meaning.

"I apologize about the poem," he said, because he knew that it was not his place to speak of it.

"That's all right," she said with hollow cheerfulness. Her mouth jerked and her eyes darkened. "Please don't go yet."

The palms of his hands were moist. He looked around the apartment again, and he did not want to ask, to bring it out in cruel words. It was not the sort of thing one asked.

"I really must go," he repeated levelly.

She put her hands on his shoulders. "Please...."

And then he saw that she intended to bribe him in the only way she knew how, and he said, "Don't worry, I won't tell Don."

He saw relief on her face, and then he was out of the apartment, shaken. He felt as if he had been kicked in the stomach, and he was sickened and his hand trembled. He wanted to talk to someone and try to explain it.

Hertha was waiting when he came out to the street.

The fever passed; control of his body returned.

"For you?" Hertha asked.

He half propped himself up on the cot. He waved his hand weakly. "Those dead plants. You must throw them out and bring in more."

He listened tensely, imagining that he could hear the precious oxygen hiss in from the emergency tank to freshen and revitalize the dead air. Halfway down on the dial. Not enough for ten days, even for one person, unless the air was replenished by bringing in plants.

"Hertha, we've got to purify this air. Now listen. Listen carefully, Hertha. You've seen me dig up those plants on the outside?"

"Yes, I watch when you go out. I always watch, Jimmy."

"Good. You've got to do the same thing. You've got to go out and dig up some plants. You've got to bring them in here and plant them the way I did. You know which ones they are?"

"Yes," she said.

He closed his eyes, trying to think of a way to make her see how vital a thing a tiny plant could be. The complex chemistry of it bubbled to the surface of his mind. He wanted to tell her why the plants died in the artificial human atmosphere and had to be replaced every week or so. He wanted to tell her, but he was growing weaker.

"They purify the air by releasing oxygen. You understand?"

She nodded her head dumbly.

"You must bring in a great many plants, Hertha. Remember that—a great many. Don't forget that. When you go outside, through the locks, we lose air. Air is very precious, so you must bring in a great many plants."

"Yes, Jimmy."

"And you must plant them as I did."

"Yes, Jimmy."

He began to talk faster, in a race with the growing fever.

"I've gathered most of the oxygenating plants around the hut. So you may have to go into the forest to get enough."

"The—the forest?"

"You must, Hertha! You must!"

Her mouth twisted as if she were ready to cry. "For you. Yes, for you I will go into the forest."

The fever came back. His mind wandered away.

He was walking in the open air. He walked from Nineshime to Venus, down Venus to Windopole, up Windopole to "The Grand Eagle and Barrel." He went in. Hertha came with him and sat down by his side at the bar.

The bartender looked at him oddly. "She with you, Mac?"

He turned to look at her; her dumb, brown eyes met his. He wanted to snarl: "Get the hell away! Leave me alone!" But he choked back the words. It was not Hertha he was angry with. She had done him no injury. She had merely followed him, perhaps because she knew of nothing else to do; perhaps because of temporary gratitude for the coins; perhaps in hope that he would buy her a drink. When the anger passed, he felt sorry for her again.

He said, "Want a drink?"

She shook her head without changing expression.

He looked at her and shrugged and thought that after a while she would get tired and go away. He ordered, and the bartender brought a bottle and one glass.

Hertha continued to stare at him; he tried to ignore her.

He drank. He thought it would get easier to ignore her as the level of the bottle fell. It didn't. He drank some more. It grew late.

"I gotta explain," he said, the liquor swirling in his mind.

She waited, cow-eyed.

"Ernest Dowson. Man's name. He wrote a poem—Beata Solitudo. I wanna explain this. Man lived long, long, long, long time ago. You listenin'? Okay. That's good. That's fine. He said—it's ver' importan' you should unnerstan' this—he said how you put honor and labor out of your mind when you ... you're out here. What he meant, it's ... it's ... you see.... Now I gotta make you see all this. So you listen real close while I tell it to you. There was a man named...."

He wanted to explain how the frontier does things to people. He wanted to explain how society is a tight little box that keeps everything locked up and hidden, but how society breaks down and becomes fluid in the stars, and how people explode and forget what they learned in civilization, and how everything is unstable.

"This man, his name's—" he said.

He wanted to explain how the harsh elements and brute nature and space, the God-awful emptiness and indifference and the sense of aloneness and selfishness and....

There were a thousand things he wanted to tell her. They were all the things he had thought about as he followed the frontier. If he could get it all down right, he could make her see why he had to follow the frontier as long as there was anything left inside of him.

Maybe the rest of the people out here were that way, too. Maybe he had seen it in Doris' eyes tonight. Maybe that was why society broke down in the stars and civilization came only when men and women like him were gone.

He did not want to know how the rest felt. He did not know whether it would be more terrifying to learn that he was alone, or that he was not alone.

But just for tonight, he could tell the alien creature beside him. It would be safe to tell her—if the idea had not rusted inside of him so long that there were no longer any words to fit it.

But first he had to make her see his home planet and the great cities and the landscaped valleys and the majestic mountains and the people. He had to make her see the vast sweep of the explorers who first carried the race to a million planets, who devised faster-than-light ships and metals to make the ships out of, metals to hold their forms in the crucible beyond normal space. He had to make her see the colonists who tied all the world together with spans of steel commerce and then moved on in ever-widening circles. He wanted to give her the whole picture.

Then he wanted to explain the surge, the restlessness of the men at the frontier. Different men, he thought; from the womb of civilization, but unlike their brothers. The men who pushed out and out. Searching, always searching. He was afraid to find out if their reasons were the same as his. For himself, he had seen a thousand planets and a thousand new life-forms. But it was not enough. There were the vast, blank, empty, indifferent reaches of space beyond him, and that was what drove him on.

This he wanted to say to Hertha: No matter how far you go, the thing that gets you is that there's nothing that cares; no matter how far, the thing is that nothing cares; the thing is that nothing cares. It gets you. And you have to go on because some day, somewhere, there may be—something.

But he lost the trend of his thoughts completely, and he had another drink.

"Decent people come out here...."

What was he going to say about decent people?

"Stupid!" he cried, slapping her in the face.

She rubbed her cheek. "Stupid?"

He wanted to cry, for he had not known that he was brutal. "Can't you see?" he screamed, and it was necessary to explain it to her; and then it was not necessary. "You're like the awful, indifferent, mindless blackness of space, unreasoning!"

"Unreasoning," she repeated carefully.

"You're Hertha!"

"I'm Hertha," she said.

The period of calmness that returned after the fever was crystal and lucid, preceding, he knew, a severe, prolonged seizure.

"I'm afraid," she told him, shivering, "but I will go."

He watched her get into the light surface suit, clamp down the helmet with trembling hands. He was shaking with nervousness as she hesitated at the lock. Then she pulled it open. It clicked behind her. He heard the brief hiss of the oxygen replacing the air that had whooshed out.

And he felt sorry for her, alone, terrified, on the scaly, hard surface of the tiny satellite. He closed his eyes, pictured her walking past his strip mine, past the gleaming heap of minerals ready for the transport.

He felt tears in his eyes and yet he could not entirely explain his feelings toward her—half fear, sometimes half affection. But more important than that: Why was she with him? What were her feelings? Had some sense of gratitude made her come? Affection?

He could not understand her. At times she seemed beyond all understanding. Her responses were mindless, almost mechanical, and that frightened him.

He remembered her dumb, apologetic caresses and her pathetically clumsy tenderness—or reflex; he could never be sure—and her eager yet reluctant hands and the always slightly hurt, slightly accusing look in her eyes, as if at every instant she was ready for a stinging blow, and her great sighs, muted as if fearing to be heard and....

He was drunk, screaming meaninglessly, and the bartender threw him out. The pavement cut his face. When he awoke, it was morning and he was in a strange room and she was in bed beside him.

She said, "I am Hertha. I brought you home. I will go with you."

The paralysis set in. He could not move. The tears froze on his cheeks, and he lay inert, thinking of her almost mindlessly fighting for his life in the alien outside.

Then she was back in the hut. So soon?

She looked at him, smiled through the transparent helmet at him. He could hear the precious oxygen hiss in to compensate for the air that had been lost when she entered.

He could see her eyes. They were proud. Relieved, too, as if she had been afraid he would be gone when she returned. He felt she had hurried back to be sure that he was still there.

She knelt by the flower bed and, without removing her suit, she held up the plant proudly. He could see the hard-packed dirt in the roots. Fascinated, he watched her scrape a planting hole. He watched her set the plant delicately and pat the soil with care.

Then she stood up.

He tried to move, to cry out. He could not.

He watched her until she went out of the range of his fixed eyes. She was going to the airlock again.

After a moment he heard the familiar hiss of oxygen.

She was going to get a great number of plants.

But one at a time.