"You can't go in there!" Heidi shrieked as the office door was suddenly thrown wide.

Mark Greenberg, deep in the tangled convolutions of a legal brief, looked up, startled at the interruption. His secretary came through the doorway, propelled by the two men who held her arms. Mark dropped the thick sheaf of papers, picked up the phone, and dialed the police.

"I want three minutes of your time," one of the men said, stepping forward. "Your girl would not let us in. It is important. I will pay. One hundred dollars a minute. Here is the money."

The bank notes were placed on the blotter, and the man stepped back. Mark finished dialing. The money was real enough. They released Heidi, who pushed their hands away. Beyond her was the empty outer office; there were no witnesses to the sudden intruders. The phone rang in his ears; then a deep voice spoke

"Police Department, Sergeant Vega."

Mark hung up the phone.

"Things have been very quiet around here. You have three minutes. There will also be a hundred-dollar fee for molesting my secretary."

If he had meant it as a joke, it was not taken that way. The man who had paid the money took another bill from the pocket of his dark suit and handed it to a startled Heidi, then waited in silence until she took it and left. They were a strange pair, Mark realized. The paymaster was draped in a rusty black suit, had a black patch over his right eye, and wore black gloves as well. A victim of some accident or other, for his face and neck were scarred, and one ear was missing. When he turned back, Mark realized that his hair was really a badly fitting wig. The remaining eye, lashless and browless, glared at him redly from its deepset socket, Mark glanced away from the burning stare to look at the other man, who seemed commonplace in every way. His akin had a shiny, waxy look; other than that and his unusual rigidity, he seemed normal enough.

"My name is Arinix, your name is Mark Greenberg," The scarred man bent over the card in his hand, reading quickly in a hoarse, emotionless voice. "You served in the United States Army as a captain in the adjutant general's office and as a military police officer. Is that correct?"

"Yes, but-"

The voice ground on, ignoring his interruption. "You were born in the state of Alabama and grew up in the city of Oneida, New York. You speak the language of the Iroquois, but you are not an Indian. Is that true?"

"It's pretty obvious. Is there any point to this questioning?"

"Yes. I paid for it. How is it that you speak this language?" He peered closely at the card as though looking for an answer that was not there.

"Simple enough. My father's store was right next to the Oneida reservation. Most of his customers were Indians, and I went to school with them. We were the only Jewish family in town, and they didn't seem to mind this, the way our Polish Catholic neighbors did. So we were friends; in minorities there is strength, you might say-"

"That is enough."

Arinix drew some crumpled bills from his side pocket, looked at them, and shoved them back. "Money," he said, turning to his silent companion. This man had a curious lizardlike quality for only his arm moved; the rest of his body was still, and his face fixed and-expressionless, as he took a thick bundle of bills from his side pocket and handed it over.

Arinix looked at it, top and bottom, then dropped it onto the desk.

"There is ten thousand dollars here. This is a fee for three days' work. I wish you to aid me. You will have to speak the Iroquois language. I can tell you no more."

"I'm afraid you will have to, Mr. Arinix. Or don't bother, it is the same to me. I am involved in a number of cases at the moment, and it would be difficult to take off the time. The offer is interesting, but I might lose that much in missed fees, Since your three minutes are up, I suggest you leave."

"Money," Arinix said again, receiving more and more bundies from his assistant, dropping them on Mark's desk. "Fifty thousand dollars. Good pay for three days. Now, come with us."

It was the man's calm arrogance that angered Mark, the complete lack of emotion, or even interest, in the large sums he was passing over.

"That's enough. Do you think money can buy everything?"

"Yes."

The answer was so sudden and humorless that Mark had to smile. "Well, you probably are right. If you keep raising the ante long enough, I suppose you will eventually reach a point where you can get anyone to listen. Would you pay me more than this?"

"Yes. How much?"

"You have enough here. Maybe Fm afraid to find out how high you will go. For a figure like this, I can take off three days. But you will have to tell me what is going to happen." Mark was intrigued, as much by the strange pair as by the money they offered.

"That is impossible. But I can tell you that within two hours you will know what you are to do. At that time you may refuse, and you will still keep the money. Is it agreed?"

A lawyer who is a bachelor tends to take on more cases than do his married associates-who like to see their families once in a while. Mark had a lot of work and a lot of money, far more than he had time to spend. It was the novelty of this encounter, not the unusual fee, that attracted him. And the memory of a solid two years of work without a single vacation. The combination proved irresistible.

"Agreed- Heidi," he called out, then handed her the money when she came into the office. "Deposit this in the number-two special account and then go home. A paid holiday. I'll see you on Monday."

She looked down at the thick bundle of bills, then up at the strangers as they waited while Mark took his overcoat from the closet. The three of them left together, and the door closed. That was the last time that she or anyone else ever saw Mark Greenberg.

It was a sunny January day, but an arctic wind that cut to the bone was blowing up from the direction of the Battery. As they walked west, it caught them at every cross street, wailing around the building corners. Although they wore only suit jackets, neither of the strange men seemed to notice it. Nor were they much on conversation. In cold and silent discomfort they walked west, a few blocks short of the river, where they entered an old warehouse building. The street door was unlocked, but Arinix now secured it behind them with a heavy bolt, then turned to the inner door at the end of the hall. It appeared to be made of thick steel plates riveted together like a ship's hull, and had a lock in each corner. Arinix took an unusual key from his pocket. It was made of dull, ridged metal, as thick as his finger and as long as a pencil. He inserted this in each of the four locks, giving it a sharp twist each time before removing it. When he was done, he stepped away, and his companion put his shoulder against the door and pushed hard. After a moment it slowly gave way and reluctantly swung open. Arinix waved Mark on, and he followed them into the room beyond.

It was completely commonplace. Walls, ceilings, and floor were painted the same drab tone of brown. Lighting came from a translucent strip in the ceiling; a metal bench was fixed to the far wall next to another door.

"Wait here," Arinix said, theo went out through the door.

The other man was a silent, unmoving presence. Mark looked at the bench, wondering if he should sit down, wondering too if he had been wise to get involved in this, when the door opened and Arinix returned.

"Here is what you must do" he said. "You will go out of here and will note this address, and then walk about the city. Return here at the end of an hour."

"No special place to go, nothing to do? Just walk around?"

"That is correct."

He pulled the heavy outer door open as he spoke, then led the way through it, down the three steps, and back along the hall. Mark followed him, then wheeled about and pointed back.

"These steps! They weren't there when we came in-no steps, I'll swear to it."

"One hour, no more, I will hold your topcoat here until you return."

Warm air rushed in, bright sunlight burned on the stained sidewalk outside. The wind still blew, though not as strongly, but now it was as hot as from an oven door. Mark hesitated on the doorstep, sweat already on his face, taking off the heavy coat.

"I don't understand. You must tell me what-"

Arinix took the coat, then pushed him suddenly in the back. He stumbled forward, gained his balance instantly, and turned just as the door slammed shut and the bolt ground into place. He pushed, but it did not move. He knew that calling out would be a waste of time. Instead, he turned, eyes slitted against the glare, and stared out at the suddenly changed world.

The street was empty, no cars passed, no pedestrians were on the sidewalk. When he stepped out of the shadowed doorway, the sun smote him like a golden fist. He took his jacket off and hung it over his arm, and then his necktie, but he still ran with sweat. The office buildings stared blank-eyed from their tiered windows; the gray factories were silent, Mark looked about numbly, trying to understand what had happened, trying to make sense of the unbelievable situation. Five minutes ago it had been midwinter, with the icy streets filled with hurrying people. Now it was… what?

In the distance the humming, rising drone of an engine could be heard, getting louder, going along a nearby street. He hurried to the corner and reached it just in time to see the car roar across the intersection a block away. It was just that, a car, and it had been going too fast for him to see who was in it. He jumped back at a sudden shrill scream, almost at his feet, and a large seagull hurled itself into the air and flapped away. It had been tearing at a man's body that lay crumpled in the gutter. Mark had seen enough corpses in Korea to recognize another one, to remember the never-forgotten smell of corrupted flesh. How was it possible for the corpse to remain here so long, days at least? What had happened to the city?

There was a growing knot of unreasoned panic rising within him, urging him to run, scream, escape. He fought it down and turned deliberately and started back toward the room where Arinix was waiting. He would spend the'rest of the hour waiting for that door to open, hoping he would have the control to prevent himself from beating upon it. Something had happened, to him or the world, he did not know which, but he did know that the only hope of salvation from the incredible events of the morning lay beyond that door. Screaming unreason wanted him to run; he walked slowly, noticing for the first time that the street he was walking down ended in the water. The buildings on each side sank into it as well, and there, at the" foot of the street, was the roof of a drowned wharf. All this seemed no more incredible than anything that had happened before, and he tried to ignore it. He fought so hard to close his mind and his thoughts that he did not hear the rumble of the truck motor or the squeal of brakes behind him.

"That man! What are you doing here?"

Mark spun about. A dusty, open-bodied truck had stopped at the curb, and a thin blond soldier was swinging down from the cab. He wore a khaki uniform without identifying marks and kept his hand near the large pistol in a polished leather holster that swung from his belt. The driver was watching him, as were three more uniformed men in the back of the truck, who were pointing heavy rifles in his direction. The driver and the soldiers were all black. The blond officer had drawn his pistol and was pointing it at Mark as well.

"Are you with the westenders? You know what happens to them, don't you?"

Sudden loud firing boomed in the street, and thinking he was being shot at, Mark dropped back against the wall. But no shots were aimed, in his direction. Even as they were turning, the soldiers in the truck dropped, felled by the bullets. Then the truck itself leaped and burst into flames as a grenade exploded. The officer had wheeled about and dropped to one knee and was firing his pistol at Arinix, who was sheltered in a doorway across the street, changing clips on the submachine gun he carried.

Running footsteps sounded, and the officer wheeled to face Arinix's companion, who was running rapidly toward him, empty-handed and cold-faced.

"Watch out!" Mark called as the officer fired.

The bullet caught the running man in the chest, spinning him about. He tottered but did not fall, then came on again. The second shot was to his head, but before the officer could fire again, Mark had jumped forward and chopped him across the wrist with the edge of his hand, so that the gun jumped from his fingers.

"Varken hand!" the man cried, and swung his good fist toward Mark.

Before it could connect, the runner was upon him, hurling him to the ground, kicking him in the head, again and again, with a heavy boot. Mark pulled at the attacker's arm, so that he lost balance and had to stagger back, turning about. The bullet had caught him full in the forehead, leaving a neat, dark hole. There was no blood. He looked stolidly at Mark, his features expressionless, his skin smooth and shiny.

"We must return quickly," Arinix said as he came up. He lowered the muzzle of the machine gun and would have shot the unconscious officer if Mark hadn't pushed the barrel aside.

"You can't kill him, not like that."

"I can. He is dead already."

"Explain that." He held firmly to the barrel. 'That and a lot more."

They struggled in silence for a second, until they were aware of an engine in the distance getting louder and closer. Arinix turned away from the man on the sidewalk and started back down the street. "He called for help on the radio. We must be gone before they arrive."

Gratefully Mark hurried after the other two, happy to run now, run to the door to escape this madness.

"A drink of water," Arinix said. Mark dropped onto the metal bench in the brown room and nodded, too exhausted to talk. Arinix had a tray with glasses of water, and he passed one to Mark, who drained it and took a second one. The air was cool here, feeling frigid after the street outside, and with the water, he was soon feeling better. More relaxed, at ease, almost ready to fall asleep. As his chin touched his chest, he jerked awake and jumped to his feet.

"You drugged the water," he said.

"Not a strong drug. Just something to relax you, to remove the tension. You will be better in a moment. You have been through an ordeal."

"I have… and you are going to explain it!"

"In a moment."

"No, now!"

Mark wanted to jump to his feet, to take this strange man by the -throat, to shake the truth from him. But he did nothing. The desire was there, but only in an abstract way. It did not seem important enough to pursue such an energetic chain of events. For the first time he noticed that Arinix had lost his hairpiece during the recent engagement. He was as hairless as an egg, and the same scars that crisscrossed his face also extended over his bare skull. Even this did not seem important enough to comment upon. Awareness struck through,

"Your drug seems to be working."

"The effect is almost instantaneous."

"Where are we?"

"In New York City."

"Yes, I know, but so changed. The water in the streets, those soldiers, and the heat. It can't be January-have we traveled in time?"

"No, it is still January, the same day, month, year it has always been. That cannot be changed, that is immutable."

"But something isn't; something has changed. What is it?"

"You have a very quick mind, you make correct conclusions. You must therefore free this quick mind of all theories of the nature of reality and of existence. There is no heaven, there is no hell, the past is gone forever, the unstoppable future sweeps toward us endlessly. We are fixed forever in the now, the inescapable present of our world line-"

"What is a world line?"

"See… the drug relaxes, but your brain is still lawyer-sharp. You live in a particular present because of what happened in the past. Columbus discovered America, the armies of the North won the Civil War, Einstein stated that E = MC²"

He stopped abruptly, and Mark waited for him to go on, but he did not. Why? Because he was waiting for Mark to finish for him. Mark nodded.

"What you are waiting for is for me to ask if there is a world line where Columbus died in infancy, where the South won, and so forth. Is that what you mean?"

"I do. Now, carry the analogy forward."

"If two or three world lines exist, why, more, any number, an infinity of world lines can exist. Infinitely different, eternally separate." Then he was on his feet, shaking despite the drug. "But they are not separate. We are in a different one right now. There is a different world line beyond that door, down those steps-because the ground here is at a different height. Is that true?"

"Yes."

"But why, how… I mean, what is going on out there, what terrible thing is happening?"

"The sun is in the early stages of a change. It is getting warmer, giving out more radiation, and the polar ice caps are beginning to melt. The sea level has risen, drowning the lowest parts of the city This is midwinter, and you saw how warm it is out there. You can imagine what the tropics are like. There has been a breakdown in government as people fled the drowning shorelines. Others have taken advantage of it. The Union of South Africa has capitalized on the deteriorating conditions, and using mercenary troops, has invaded the North American continent. They met little resistance."

"I don't understand-or rather, I do understand what is happening out there, and I believe you, because I saw it for myself. But what can I do about it? Why did you bring me here?"

"You can do nothing about it. I brought you here because we have discovered by experience that the quickest way that someone can be convinced of the multiplicity of worldliness is by bringing them physically to a different world line."

"It is also the best-and quickest-way to discover if they can accept this fact and not break down before this new awareness."

"You have divined the truth. We are, unfortunately, short of time, so wish to determine as soon as possible if recruits will be able to work with us."

"Who is we?"

"In a moment I will tell you. First, do you accept the idea of the multiplicity of world lines?"

"I'm afraid I must. Outside is an inescapable fact. That is not a stage constructed to confuse me. Those dead men are dead forever. How many world lines are there?"

"An infinite number; it is impossible to know. Some differ greatly, some so slightly that it is impossible to mark the difference. Imagine them, if you will, as close together as cards in a pack. If two-dimensional creatures, cluba and hearts, lived on each card, they would be unaware of the other cards and just as unable to reach them. Continue the analogy, drive a nail through all of the cards. Now the other cards can be reached. My people, the 'we' you asked about, are the ones who can do that. We have reached many world lines. Some we cannot reach-some we dare not reach."

"Why?"

"You ask why-after what you saw out there?" For the first time since they had met, Arinix lost his cold detachment. His single eye blazed with fury, and his fists were clenched as he paced the floor. "You saw the filthy things that happen, the death that comes before the absolute death. You see me, and I am typical of my people, maimed, killed, and scarred by a swollen sun that produces more and more hard radiation every year. We escaped our world line, seeking salvation in other world lines, only to discover the awful and ultimate secret. The rot is beginning, going faster and faster all the time. You saw what the world is like beyond that door. Do you understand what I am saying, do the words make any sense to you?

"The sun is going nova. It is the end."

"Water," Arinix called out hoarsely, slumping onto the metal bench, his single eye closed now. The inner door opened, and his companion appeared with a pitcher and refilled the glasses. He moved as smoothly as before and seemed ignorant of the black hole in his forehead.

"He is a Sixim," Arinix said, seeing the direction of Mark's gaze. He drank the water so greedily that it ran down his chin. "They are our helpers; we could not do without them. Not our invention. We borrow what we need. They are machines, fabrications of plastic and metal, though there is artificial flesh of some kind involved in their construction. I do not know the details. Their controlling apparatus is somewhere in the armored chest cavity; they are quite invulnerable."

Mark had to ask the question.

"The sun is going nova, you said. Everywhere, in every time line-in my time line?"

Arinix shook his head a weary no. "Not in every line; that is our only salvation. But in too many of them-and the pace is accelerating steadily. Your line-no, not as far as we know. The solar spectrum does not show the characteristic changes. Your line has enough problems as it is, and is one we use for much-needed supplies. There are few of us, always too few, and so much to be done. We must save whom we can and what we can, do it without telling why or how we operate. It is a great work that does not end, and is a most tiring one. But my people are driven, driven insane with hatred, at times, of that bloated, evil thing in the sky. We have survived for centuries in spite of it, maimed and mutated by the radiation it pours out. It was due to a successful mutation that we escaped even as we have, a man of genius who discovered the door between the world lines. But the unsuccessful outnumber a million to one the successful in mutations, and I will not attempt to describe the suffering in my world. You may think me maimed, but I am one of the lucky ones. We have escaped our world line but found the enemy waiting everywhere. We have tried to fight back. We started less than two hundred years ago, and our enemy started millions of years before us. From it we have learned to be ruthless in the war, and we will go on fighting it until we have done everything possible."

"You want me to do something in that world outside the door?"

"No, not there; they are dead. The destruction is too advanced. We can only watch. Closer to the end, we will save what art we can. Things have been noted. We know a culture by its art, don't we? We know a world that way as well. So many gone without record, so much to do."

He drank greedily at the water, slobbering. Perhaps he was mad, Mark thought, partly mad, at least. Hating the sun,trying to fight it, fighting an endlessly losing battle. But… wasn't it worth it? If lives, people, could be saved, wasn't that worth any price, any sacrifice? In his world line, men worked to save endangered species. Arinix and his people worked to save another species-their own.

"What can I do to help?" Mark asked.

"You must find out what happened to our field agent in one of our biggest operations. He is from your world line, the one we call Einstein because it is one of the very few where atomic energy has been released. He is now on Iroquois, which will begin going nova within the century. It is a strange line, with little technology and retarded by monolithic religions. Europe still lives in the dark ages. The Indians rule in North America, and the Six Nations are the most powerful of all. They are a brave and resourceful people, and we had hoped to use them to settle a desert world-we know of many of those. Imagine, if you can, the Earth where life never began, where the seas are empty, the land a desert of sand and rock. We have seeded many of them, and that is wonder to behold, with animal and plant life. Simple enough to introduce seeds of all kinds, and later, when they have been established, to transfer animals there. Mankind is not as easy to transfer. We had great hopes with the Iroquois, but our agent has been reported missing. I have taken time from my own projects to correct the matter. We used War Department records to find you."

"Who was your agent?"

"A man named Joseph Wing, a Mohawk, a steel worker here in the city in your own line."

"There has always been bad feeling between the Mohawk and other tribes of the nations."

"We know nothing about that, I will try to find his reports,, if any, if that will be of any assistance. The important thing is-will you help us? If you wish more money, you can have all you need. We have an endless supply. There is little geologic difference between many worlds. So we simply record where important minerals are on one world, things such as diamonds and gold, and see that it is mined on another. It is very easy."

Mark was beginning to have some idea of the immensity of the operation these people were engaged in. "Yes, I'll help, I'll do what I can."

"Good. We leave at once. Stay where you are. We go now to a world line that is called Home by some, Hatred by others."

"Your own?"

"Yes. You will perhaps understand a bit more what drives us. All of our geographical transportation is done on Hatred, for all of the original transit stations were set up there. Also, that is all it is really good for." He spat the words from his mouth as though they tasted bad.

Again there was no sensation, no awareness of change, Arinix left the room, returned a few seconds later.

"You wouldn't like to show me how you did that?" Mark asked.

"I would not. It is forbidden, unthinkable. It would be death for you to go through that door. The means of transit between the world lines is one we must keep secret from all other than ourselves. We may be partially or completely insane, but our hatred is of that thing that hangs in the sky above us. We favor no group, no race, no people, no species above the others. But think what would happen if one of your nationalistic or religious groups gained control of the means to move between world lines, think of the destruction that might follow."

"I grasp your meaning but do not agree completely."

"I do not ask you to. All else is open to you; we have no secrets. Only that room is forbidden. Come."

He opened the outer door, and Mark followed him through.

They were inside a cavernous building of some kind. Harsh lights high above sent long shadows from great stacks of containers and boxes. They stepped aside as a rolling platform approached laden with shining cylinders. It was driven by a Sixim, who was identical, other than the hole in the forehead, to the one with them. The door they had just closed behind them opened, and two more Sixim came out and began to carry the cylinders back into the room.

"This way," Arinix said, and led the way through the high stacks to a room where bales of clothing lay heaped on tables. "Go on to repair," he ordered the damaged Sixim that still followed them, then pointed at the gray clothing.

"These are radiation-resistant. We will change."

As bereft of shame as of any other emotion, Arinix stripped off his clothing and pulled on one of the coverall-type outfits. Mark did the same. It was soft but thick and sealed up high on the neck with what appeared to be a magnetic closure. There were heavy boots in an assortment of sizes, and he soon found a pair that fitted. While he did this, Arinix was making a call on a very ordinary-looking phone that was prominently stamped "Western Electric"-they would be surprised if they knew where their apparatus was being used- speaking a language rich in guttural sounds. They left the room by a different exit, into a wide corridor, where transportation was waiting for them. It was a vehicle the size of a large truck, a teardrop shape riding on six large, heavily tired wheels. It was made of metal the same color as their clothing, and appeared to have no windows. However, when they went inside, Mark saw that the solid nose was either transparent or composed of a large viewsereen of some kind. A single driver's seat faced the controls, and a curved, padded bench was fixed to the other three walls. They sat down, Arinix at the controls, and the machine started. There was no vibration or sound of any exhaust; it just surged forward silently at his touch.

"Electric power?" Mark asked.

"I have no idea. The cars run when needed."

Mark admired his singleness of purpose but did not envy him. There was only one thing in the man's life-to run from the solar fire and save what possibly could be saved from the flame. Were all of his'people like this?

Strong headlights glared on as they left the corridor and entered what appeared to be a tunnel mouth. The walls were rough and unfinished; only the roadway beneath was smooth, dropping away at a steep angle,

"Where are we going?" Mark asked.

"Under the river, so we can drive on the surface. The island above us-what is the name Einstein-?"

"Manhattan."

"Yes, Manhattan. It is covered by the sea now, which rises almost to the top of the cliffs across the river from it The polar caps melted many years ago here. Life is very harsh, you will see."

The tunnel ahead curved to the right and began to rise sharply. Arinix slowed the vehicle and stopped when a brilliant disk of light became visible ahead. He worked a control, and the scene darkened as though a filter had been slipped into place. Then, with the headlights switched off, he moved forward until the light could be seen as the glaring tunnel mouth, growing larger and brighter, until they were through it and back on the surface once more.

Mark could not look at the sun, or even in its direction, despite the protective filter. It burned like the open mouth of a celestial furnace, spewing out light and heat and radiation onto the world below. Here the plants grew, the only living creatures that could bear the torrent of fire from the sky, that welcomed it. Green on all sides, a jungle of growing, thriving, rising, reaching plants and trees, burgeoning under the caress of the exploding star. The road was the only visible manmade artifact, cutting a wide, straight slash through the wilderness of plant life, straining life that leaned over, grew to its very edge, and sent tendrils and runners across its barren surface. Arinix threw more switches, then rose from the driver's seat.

"It is on automatic control now. We may rest."

He grabbed for support as the car slowed suddenly; ahead, a great tree had crashed across the road, almost blocking it completely. There was a rattle of machinery from the front of the car, and a glow sprang out that rivaled the glare of the sun above. Then they moved again, slowly, and greasy smoke billowed up and was blown away.

'The machine will follow the road and clear it when it must," Arinix said. "A device, a heat generator of some sort, will burn away obstructions. I am told it is a variant of the machine that melted the soil and rock to form this road, a principle discovered while observing the repulsive sun that has caused this all, making heat in the same manner the sun makes heat. We will turn its own strengths back upon it."

He went to the seat in the rear, stretched out on it with his face to the cushions, and appeared to fall instantly asleep, Mark sat in the driver's chair, careful to touch nothing, both fascinated and repelled by the world outside. The car continued unerringly down the center of the road at a high speed, slowing only when it had to burn away obstructions. It must have utilized radar or other sensing devices, for a_ sudden heavy rainstorm did not reduce its speed in the slightest. Visibility was only a few feet in the intense tropical downpour, yet the car moved on, speed unabated. It did slow, but only to burn away obstructions, and smoke and steam obscured all vision. Then the storm stopped, as quickly as it began. Mark watched until he began to yawn, so then, like Arinix, he tried to rest. At first he thought he could not possibly sleep, then realized he had. Darkness had fallen outside, and the car still hurried silently through the night.

It was just before dawn when they reached their destination.

The building was as big as a fortress, which it resembled in more ways than one. Its walls- were high and dark, featureless, streaked with rain. Harsh lights on all sides lit the ground, which was nothing more than sodden ash. Apparently all plant life was burned before it could reach the building and undermine it. The road led directly to a high door that slid open automatically as they approached. Arinix stopped the vehicle a few hundred yards short of the entrance and rose from the controls.

"Come with me. This machine will enter by itself, but we shall walk. There is no solar radiation now, so you may, see my world and know what is in store for all the others."

They stepped out into the damp airlessness of the night. The car pulled away from them, and they were alone. Rivulets of wet ash streaked the road, disappearing in runnels at either side where the waiting plant life leaned close. The air was hot, muggy, hard to breathe, seemingly giving no substance to the lungs. Mark gasped and breathed deeply over and over again,

"Remember," Arinix said, turning away and starting for the entrance, "this is night, midwinter, before dawn, the coolest it will ever be here. Do not come in the summer."

Mark went after him, aware that he was already soaked with sweat, feeling the strength of the enemy in the sky above, which was already touching fire to the eastern horizon. Though he panted with the effort, he ran and staggered into the building and watched as the door ground shut behind him.

"Your work now begins;" Arinix said, leading the way into a now familiar brown room. Mark got his breath back and wiped his streaming face while they made their swift journey to the world line named Iroquois,

"I will leave you here and will return in twenty-four hours-for your report on the situation. We will then decide what must he -done." Arinix opened the outer door and pointed.

"Just a minute-I don't know anything that is happening here. You will have to brief me."

"I know nothing of this operation, other than what I have told you. The Sixim there should have complete records and will tell you what you need to know. Now, leave. I have my own work to do."

There was no point in arguing, Arinix gestured again impatiently, and Mark went through the door, which closed with a ponderous thud behind him. He was in darkness, cold darkness, and he shivered uncontrollably after the heat of the world he had just left.

"Sixim, are you there? Can you turn on some lights?"

There was the sudden flare of a match in answer, and in its light he could see an Indian lighting an ordinary kerosene lamp. He wore thong-wrapped fur leggings and a fringed deerskin jacket. Though his skin was dark, his features were Indo-European; once the lamp was lit, he stood by it, un-moving,

"You are the Sixim," Mark said.

"I am."

"What are you doing here?"

"Awaiting instructions."

These creatures were as literal-minded as computers- which is probably what their brains were. Mark realized he had to be more specific with his questions, but his teeth were chattering with cold, and he was shivering hard, which made it difficult to think.

"How long have you-been waiting?"

"Twelve days, fourteen hours, and-"

"That's precise enough. You have just been sitting here in the dark without heat all that time! Do you have a way of heating this place?"

"Yes."

"Then do it, and quickly… and let me have something to wrap around me before I freeze."

The buffalo-skin robe made a big difference, and while the Sixim lit a fire in a large stone fireplace, Mark looked around at the large room. The walls were of logs, with the bark still on, and the floor bare wide boards. Crates were piled at one end of the room, and a small mound of skins was at the other. Around the fire, it was more domestic, with a table and chairs, cooking pots, and cabinets. Mark pulled a wooden chair close and raised his hands to the crackling blaze. Once the fire was started, the Sixim waited stolidly again for more orders.

By patient questioning Mark extracted all that the machine man seemed to know about the situation. The agent, Joseph Wing, had been staying here and going out to talk to the Oneida. The work he did was unknown to the, Sixim." Wing had gone out and not returned. At the end of forty-eight hours, as instructed, the Sixim had reported him missing. How he had reported, he would not say; obviously there were questions it would not answer.

"You've been a help-but not very much," Mark said, "I'll just have to find out for myself what is going on out there. Did Joseph Wing leave any kind of papers, a diary, notes?"

"No."

"Thanks. Are there any weapons here?"

"In that box Do you wish me to unlock it?"

"I do."

The weapons consisted of about twenty well-worn, obviously surplus M-1 rifles, along with some boxes of ammunition. Mark tried the bolt on one-it worked smoothly- then put the rifle back in the box.

"Lock it up. I'm not looking for trouble, and if I find it, a single gun won't make that much difference. But a peace offering might be in order, particularly food in the middle of winter."

He carried the lantern over to the boxes and quickly found exactly what he needed. A case of large smoked hams. Picking one out, he held the label to the light, "Smithfield Ham," it read, "packed in New Chicago, weight 6.78 kilos." Not from his world line, obviously, but that didn't matter in the slightest.

And he would need warmer clothes, clothes that would be more acceptable here than gray coveralls. There were leggings and jackets-obviously used, from their smell-that would do nicely. He changed quickly in front of the fire, then, knowing it would be harder the longer he waited, tucked the ham under his arm and went to the door and pulled back on the large wooden bolt.

"Lock this behind me, and unlock it only for me."

"Yes."

The door opened onto an unmarked field of snow with a stand of green pines and taller bare-limbed oak trees beyond. Above, in the blue arch of the sky, a small and reasonable winter sun shed more light than heat. There was a path through the trees, and beyond them a thin trickle of smoke was dark against the sky. Mark went in that direction. When he reached the edge of the grove, a tall Indian stepped silently from behind a tree and blocked the path before him. He made no threatening moves, but the stone-headed club hung easily and ready from his hand. Mark stopped and looked at him, saying nothing, hoping he could remember Iroquois after all these years. It was the Indian who broke the silence and spoke first,

"I am called Great Hawk."

"I am called… Little-one-talks." He hadn't spoken that name in years; it was what the old men on the reservation called him when he first spoke their own language. Great Hawk seemed to be easier when he heard the words, for his club sank lower.

"I come in peace," Mark said, and held out the ham.

"Welcome in peace," Great Hawk said, tucking the club into his waist and taking the ham. He sniffed at it appreciatively.

"Have you seen the one named Joseph Wing?" Mark asked.

The ham dropped, half-burying itself silently in the snow; the club was clutched at the ready.

"Are you a friend of his?" Great Hawk asked.

"I have never met him. But I was told I would see him here."

Great Hawk considered this in silence for a long time, looked up as a blue jay flapped by overhead, calling out hoarsely, then examined with apparent great attention the tracks of a rabbit in the snow-through all of this not taking his eyes from Mark for more than a second,. Finally he spoke.

"Joseph Wing came here during the hunter's moon, before the first snow fell. Many said-he had much orenda, for there were strange lights and sounds here during a night, and no one would leave the long house, and in the morning his long house stands as you see it now. There is great orenda here. Then he came and spoke to us and told us many things. He said he would show the warriors a place where there was good hunting. Hunting is bad here, for the people of the Six Nations are many, and some go hungry. He said all these things, and what he showed us made us believe him. Some of us said we would go with him, even though some thought they would never return. Some said that he was Tehoron-hiawakhon, and he did not say it was not the truth. He said to my sister, Deer-runs, that he was indeed Tehoronhiawak-hon. He told her to come with him to his long house. She did not want to go with him. By force he took her to his long house."

Great Hawk stopped talking abruptly and looked attentively at Mark through half-closed eyes-. He did not finish, but the meaning was clear enough. The Oneida would have thought Joseph Wing possessed of much orenda after his sudden appearance, the principle of magic power that was inherent in every body or thing. Some had it more than others. A man who could build a building in a night must have great orenda. So much so that some would consider him to be Te-horonhiawakhon, the hero who watched over them, born of the gods, who lived as a man and who might return as a man. But no hero would take a maiden by force; the Indians were very practical on this point. Anyone who would do that would be killed by the girl's family; that was obvious. Her brother waited for Mark's answer.

"One who does that must die," Mark said. Defending the undoubtedly dead Joseph Wing would accomplish nothing; Mark was learning pragmatism from Arinix.

"He died. Come to the long house."

Great Hawk picked up the ham, turned his back, and led the way through the deep snow.

The Oneida warriors sat cross-legged around the fire while the women served them the thin gruel. Hunting must have been bad if this was all they had, for it was more water than anything else, with some pounded acorns and a few scraps of venison. After eating, they smoked, a rank leaf of some kind that was certainly not tobacco. Not until the ceremony was out of the way did they finally touch the topic that concerned them all.

"We have eaten elk," Great Hawk said, puffing at the pipe until his eyes grew red, "This is an elkskin robe I am wearing. They are large, and there is much meat upon them." He passed the pipe to Mark, then reached behind him under a tumbled hide and drew forth a bone, "This is the bone of the leg of an elk, brought to us by someone. We would eat well in winter with elk such as this to hunt."

Mark took it and looked at it as closely as he could in the dim light. It was a bone like any other, as far as he could tell, distinguished only by its great length-at least five feet from end to end. Comparing it with the length of his own femur, he could see that it came from a massive beast. Surely an elk or a cow would be smaller than this. What had this to do with the dead Joseph Wing? He must have brought it. But why, and where did he get it? If only there were some record of what he was supposed to be doing. Hunting, of course-that had to be it; food for these people who appeared too many for the limited hunting grounds. He held up the bone and spoke.

"Was it told to you that you would be able to hunt elk like this?"

There were nods and grunts in answer.

"What was told you?" After a silence, Great Hawk answered.

"Someone said that a hunting party could go to this land that was close by but far away. If hunting was good, a long house would be built for the others to follow. That was what was said."

It was simple enough. A hunting party taken to one of the seeded desert worlds, now stocked with game. If the trip was successful, the rest of the tribe would follow.

"I can also take you hunting in that land," Mark said,

"When will this be?"

"Come to me in the morning, and I will tell you,"

He left before they could ask any more questions. The sun was low on the horizon, sending long purple shadows across the white snow. Backtracking was easy, and the solid log walls of the building a welcome sight. When he was identified, the Sixim let him in. The fire was built even higher now, the large room was almost warmed up. Mark sat by the fire and stretched his hands to it gratefully; the Sixim was statuesque in the shadows,

"Joseph Wing was to take the Indians to another world line. Did you know that?"

"Yes."

"Why didn't you tell me?"

"You did not ask."

"I would appreciate it if you would volunteer more information in the future."

"Which information do you wish me to volunteer?"

The Sixim took a lot of getting used to. Mark took the lantern and rummaged through the variety of goods in the boxes and on the loaded shelves. There were ranked bottles of unfamiliar shape and labeling that contained some thing called Kunbula Atashan from someplace that appeared to be named Carthagio-it was hard to read the letters, so he could not be sure, but when he opened one of them, it had a definite odor of strong alcoholic beverage. The flavor was unusual but fortifying, and he poured a mugful before he returned to the fire.

"Do you know whom I must contact to make arrangements for the transfer to the other world line?"

"Yes."

"Who?"

"Me."

It was just that simple. The Sixim would give no details of the operation, but he would operate the mechanism to take them to the correct world and return.

"In the morning, first thing, we'll go have a look."

They left soon after dawn. Mark took one of the rifles and some extra clips of ammunition; that had been a big elk, and he might be lucky enough to bag another. Once more the sensationless transfer was made and the heavy outer door pushed open. For the first time there was no other room or hallway beyond it, just a field of yellowed grass. Mark was astonished.

"But… is it winter? Where is the snow?" Because it was phrased as a question, the Sixim answered him.

"It is winter. But here in Sandstone the climate is warmer, due to the ocean-current differences."

Holding the rifle ready, Mark stepped through the door, which the Sixim closed behind him. Without being ordered, the Sixim locked the door with the long key. For the first time Mark saw the means of world-line transportation not concealed by an outer building. It was a large box, nothing more, constructed of riveted and rusty steel plates. Whatever apparatus powered it was inside, for it was completely featureless. He turned from it to look at the world named Sandstone.

The tall grass was everywhere; it must have been seeded first to stabilize the soil. It had done this, but it would take centuries to soften the bare rock contours of what had once been a worldwide desert. Harsh-edged crags pushed up in the distance where there should have been rounded hills; mounds of tumbled morain rose above the grass. Groves and patches of woods lay scattered about, while on one side a thick forest began and stretched away to the horizon. All of this had a very constructed air to it-and it obviously was. Mark recognized some of the trees; others were strange to him. This planet had been seeded in a hurry, and undoubtedly with a great variety of vegetation. As unusual as it looked now, this made ecological good sense, since complex ecological relationships increased the chance the ecosystem had of surviving. There would certainly be a variety of animal life as well- the large elk the Oneida knew about, and surely others as well. When he moved around the rusty building, he saw just what some of that life might be-and stopped still on the spot. No more than a few hundred yards away, there was a herd of elephants tearing at the leaves on the low trees. Large elephants with elegant swept-back tusks, thickly covered with hair.

"Hairy mammoth!" he said aloud, just as the nearest bull saw him appear and raised his trunk and screamed warning.

"That is correct," the Sixim said.

"Get your key, and let's get out of here," Mark said, backing quickly around the corner. "I don't think a thirty-caliber will make a dent in that thing."

With unhurried, steady motions the Sixim unlocked the door, one lock after another, while the thunder of pounding feet grew louder and closer. Then they were through the door and pushing it shut.

"I think the Oneida will enjoy the hunting," Mark said, grinning wryly, leaning against the thick wall with relief, "Let's go back and get them."

When he opened the outer wooden door in Iroquois, he saw Great Hawk and five other warriors standing patiently in the snow outside. They were dressed warmly, had what must be provision bags slung at their waists, and were armed with long bows and arrows as well as stone clubs and stone skinning knives. They were prepared for a hunting expedition, they knew not where, but they were prepared. When Mark waved them forward, they came at once. The only sign of the tension they must be feeling was in their manner of walking, more like stalking a chase than entering a building. They showed little interest in the outer room-they must have been here before-but were eyeing the heavy metal door with more than casual interest. The deceased Joseph Wing must have told them something about it, but Mark had already decided to ignore this and tell the truth as clearly as they could understand it.

"Through that door is a long house that will bear us to the place where we will hunt. How it will take us there I do not know, for it is beyond my comprehension. But it will take us there as safely as a mother carries a papoose on her back, as safely as a bark canoe carries us over the waters. Are you ready to go?"

"Will you take the noise stick that kills?" Great Hawk asked, pointing with his thumb at the rifle Mark still carried.

"Yes."

"It was one time said that the Oneida would be given noise sticks and taught the manner of their use."

Why not, Mark thought, there were no rules to all this, anything went that would save these people. "Yes, you may have them now if you wish, but I think until you can use them well, your bows will be better weapons."

"That is true. We will have them when we return."

The Sixim pulled the heavy door open, and without being urged, the Indians filed into the brightly lit room beyond. They remained silent but held their weapons ready as the door was closed and the Sixim went through the door to the operating room, only to emerge a moment later.

"The journey is over," Mark said. "Now we hunt."

Only when the outer door was opened onto the grassy sunlit plain did they believe him. They grunted with surprise as they left, calling out in wonder at the strange sights and the warm temperature. Mark looked around nervously, but the herd of mammoth was gone. There were more than enough other things to capture the Indians' attention. They saw animals where he saw only grass and trees and called attention to them with pleased shouts. Yet they were silent instantly when Great Hawk raised his hand for silence, then pointed.

"There, under those trees. It looks like a large pig."

Mark could see nothing in the shadows, but the other

Indians were apparently in agreement, for they were nocking arrows to their bows. When the dark, scuffling shape emerged into the sunlight, they were ready for it, A European boar, far larger than they had ever seen. The boar had never seen men before either; it was not afraid; The arrows whistled; more than one struck home, the boar wheeled about, squealing with pain, and crashed back into the undergrowth. Whooping with pleasure, the Oneida were instantly on its trail.

"Stay inside until we get back," Mark told the Sixim. "I want to be sure we can get back."

He ran swiftly after the others, who had already vanished under the trees. The trail was obvious, marked with the blood of the fleeing animal, well trampled by its pursuers. From ahead there came even louder squealing and shouts that ended in sudden silence. When Mark came up, it was all over; the boar was on its side, dead, its skull crushed in, while the victorious Indians prodded its flanks and hams happily.

The explosion shook the ground at that moment, a long, deep rumbling sound that hammered at their ears. It staggered them, it was so close and loud, frightening them because they did not know what it was. Mark did. He had heard this kind of noise before. He wheeled about and watched the large cloud of greasy black smoke roiling and spreading as it climbed up the sky. It rose from behind the trees in the direction of the building. Then he was running, slamming a cartridge in the chamber of the rifle at the same time, thumbing off the safety.

The scene was a disaster. He stumbled and almost fell as he emerged from beneath the trees.

Where the squat steel building had stood was now only a smoking, flame-licked ruin of torn and twisting plates. On the grass nearby, one leg ripped away and as torn himself, lay the Sixim.

The doorway between the worlds was closed.

Mark just stood there, motionless, even after the Indians came up and ranked themselves beside him, calling out in wonder at the devastation. They did not realize yet that they were exiled from their tribe and their own world. The Sixim raised its head and called out hoarsely; Mark ran to it. Much of its imitation flesh was gone, and metal shone through the gaps. Its face had suffered badly as well, but it could still talk.

"What happened?" Mark asked.

"There were strangers in the room, men with guns. This is not allowed. There are orders. I actuated the destruct mechanism and attempted to use the escape device."

Mark looked at the ruin and flames. "There is no way this room can be used again?" -

"No."

"Are there other rooms on this world?"

"One that I know of, perhaps more____________________ "

"One is enough! Where is it?"

"What is the name of your world line?"

"What difference does that make?… All right, it's called Einstein."

"The room is located on an island that is named Manhattan." '

"Of course! The original one I came through. But that must be at least two hundred miles away from here as the crow flies."

But what was two hundred miles as compared to the gap between the worlds? His boots were sound, he was a couple of pounds overweight, but otherwise in good condition. He had companions who were at home in the wilds and knew how to live off the land. If they would come with him… They had little other choice. If he could explain to them what had happened and what they must do…

It was not easy, but the existence of this world led them to believe anything he told them-if not believe it, at least not to doubt it too strongly. In the end they were almost eager to see what this new land had to offer, what other strange animals there were to hunt. While the others butchered and smoked the fresh-killed meat, Mark labored to explain to Great Hawk that they were physically at the same place in the world as the one they had left. The Indian worked hard to understand this but could not, since this was obviously a different place. Mark finally forced him to accept the fact on faith, to operate as if it were true even though he knew it wasn't.

When it came to finding the island of Manhattan, Great Hawk called a conference of all the Indians. They strolled over slowly, grease-smeared and happy, stomachs bulging with fresh meat. Mark could only listen as they explored the geography of New York State, as they knew it and as they had heard of it from others. In the end they agreed on the location of the island, at the mouth of the great river at the ocean nearby the long island. But they knew they could not get there from this place, then went back to their butchery. They fell asleep in the middle of this; it was late afternoon, so he gave up any hope of starting this day. He resigned himself to the delay and was eating some of the roasted meat himself when the Sixim appeared out of the forest. It had shaped a rough crutch from a branch, which it held under its arm as it walked. Arinix had said the creatures were almost indestructible, and it appeared he was right.

Mark questioned the Sixim, but it did not know how to get to Manhattan, nor did it have any knowledge of the geography of this world. When the sun set, Mark stretched out by the fire with the others and slept just as soundly as they did. He was up at first light, and as the sun rose in the east, he squinted at it and realized what he had to do. He would have to lead them out of here. He shook Great Hawk awake,

"We walk east toward the sun," he said, "When we reach the great river, we turn and follow it downstream to the south. Can we do that?" If there were a Hudson River on this world… and if the Indians would follow him,,, Great Hawk looked at him solemnly for a long moment, then sat,up.

"We leave now." He whistled shrilly, and the others stirred.

The Indians enjoyed the outing very much, chattering about the sights along the way and looking with amusement at what was obviously a happy hunting ground. Game was everywhere-creatures they knew and others that were completely strange. There was a herd of great oxlike creatures that resembled the beasts of the cave paintings in Altamira, aurochs perhaps, and they had a glimpse of a great cat stalking them that appeared to have immensely long tusks. A sabertooth tiger? All things were possible on this newly ripening desert world. They walked for five days through this strange landscape before they reached what could only be the Hudson River.

Except that, like the Colorado River, this river had cut an immense gorge through what had formerly been a barren landscape. They crept close to the high cliffs and peered over. There was no possible way to descend.

"South," Mark said, and turned along the edge, and the others followed him.

A day later they reached a spot where a tributary joined the Hudson and where the banks were lower and more graded. In addition, many seeds had been Sown or carried here, and strands of trees lined the shore. It took the Indians less than a day to assemble branches, trunks, and driftwood to make a sizable raft. Using strips of rawhide, they bound this firmly together, loaded their food aboard, then climbed aboard themselves. As the Indians poled and paddled, the clumsy craft left shore, was carried quickly out into the main current, and hurried south. Manhattan would be at the river's mouth.

This part of the trip was the easiest, and far swifter than Mark had realized. The landscape was so different from what he -knew of the valley, with alternate patches of vegetation and desert, that he found it hard to tell where they were. A number of fair-sized streams entered the river from the east, and there was no guarantee that the East River, which cut Manhattan off from the mainland, existed on this world. If it were there he thought it another tributary, for he never saw it. There were other high cliffs, so the Palisades were not that noticeable.

"This water is no good," Great Hawk said. He had scooped up a handful from the river, and he now spat it out. Mark dipped some himself. It was brackish, salty.

"The ocean, tidewater-we're near the mouth of the river! Pull to shore, quickly."

What he had thought was a promontory ahead showed nothing but wide water beyond it, the expanse of New York Harbor. They landed on- what would be the site of Battery Park on the southernmost tip of the island. The Indians worked in silence, unloading the raft, and when Mark started to speak, Great Hawk held his finger to his lips for silence, then leaned close to whisper in his ear.

"Men over this hill, very close. Smell them, smell the fire, they are cooking meat."

"Show me," Mark whispered in return.

He could not move as silently as the Oneida did; they vanished like smoke among the trees. Mark followed as quietly as he could, and a minute later Great Hawk was back to lead him. They crawled the last few yards on their stomachs under the bushes, hearing the sound of mumbled voices. The Indian moved a branch slowly aside, and Mark looked into the clearing.

Three khaki-clad soldiers were gathered around a fire over which a smoking carcass roasted. They had heavy rifles slung across their shoulders. A fourth, a sergeant with upside-down stripes, was stretched out asleep with his wide-brimmed hat over his face.

They spoke quietly in order not to waken him, a strangely familiar language deep in their throats.

It was Dutch-not Dutch, Afrikaans. But what were they doing here?

Mark crawled back to the others, and by the time he had reached them, the answer was clear-too clear, and frightening. But it was the only possibility. He must tell them.

"Those men are soldiers. I know them. Warriors with noise sticks. I think they are the ones who took over the room and destroyed it. They are here, which must mean they have taken over the room here. Without it we cannot return."

"What must we do?" Great Hawk asked. The answer was obvious, but Mark hesitated to say it. He was a lawyer, or had been a lawyer-a man of the law. But what was the law here?

"If we are to return, we will have to kill them, without any noise, then kill or capture the others at the room. If we don't do that, we will be trapped here, cut off from the tribe forever,"

The Indians, who lived by hunting, and were no strangers • to tribal warfare, were far less worried about the killing than was Mark. They conferred briefly, and Great Hawk and three others vanished silently back among the trees. Mark sat, staring.sightlessly at the ground, trying to equate this with his civilized conscience. For a moment he envied the battered Sixim, who stood by his side, unbothered by emotions or worries. An owl called and the remaining Indians stood and called Mark after them.

The clearing was the same, the meat still smoked on the spit, the sergeant's hat was still over his eyes. But an arrow stood out starkly from his side below his arm. The huddled forms of the other soldiers revealed the instant, silent death that had spoken from the forest. With no show of emotion, the Indians cut the valuable arrows free of the corpses, commenting only on the pallid skin of the men, then looted their weapons and supplies. The guns might be useful; the arrows certainly were. Great Hawk was scouting the clearing and found a-to him-clearly marked trail. The sun was behind the trees when they started down it.

The building was not far away. They looked at it from hiding, the now familiar rusted and riveted plates of its walls, the heavy sealed door. Only, this door was gaping open, and the building itself was surrounded by a palisade of thin trees and shrubs. A guard stood at the only gate, and the enclosure wds filled with troops. Mark could see heavy weapons and mortars there.

"It will be hard to kill all of these without being killed ourselves," Great Hawk said…"So we shall not try."

The Indians could not be convinced even to consider action. They lay about in the gathering darkness, chewing on the tough slabs of meat, ignoring all of-Mark's arguments. They were as realistic as any animal, and not interested in suicide. A mountain lion attacks a deer, a deer runs from a lion-it never happens the other way around. They would wait here until morning and watch the camp, then decide what to do. But it was obvious that the options did not include an attack. Would it end this way, defeat without battle… and a barren lifetime on a savage planet stretching ahead of them? More barren to Mark, who had a civilized man's imagination and despair. The Indians had no such complications in their lives. They chewed the meat, the matter dismissed and forgotten, and in low whispers discussed the hunting and the animals while darkness fell. Mark sat, silent with despair; the Sixim loomed silent as a tree beside him. The Sixim would follow orders, but the two of them were not going to capture this armed camp. Something might happen-he must make the Indians stay and watch and help him. He doubted if they would.

Something did happen, and far sooner than he had thought. Great Hawk, who had slipped away to watch the building, came back suddenly and waved the others to follow him. They went to the fringe of the trees once more and looked at the activity in the camp with astonishment.

The gate was standing open, and there was no guard upon it.

All of the soldiers had drawn up in a semicircle facing the open door of the building. Fires had been lit near it. All of the heavy weapons had been trained on the opening.

"Don't you see what has happened!" Mark said excitedly. "They may control this building and others like it in other lines, but they cannot possibly control them all. They must be expecting a counterattack. They can do nothing until the attackers appear except wait and be ready. Do you understand-this is our chance! They are not expecting trouble from this flank. Get close in the darkness. Wait. Wait until the attack. Then we take out the machine guns-they are the real danger-sow confusion. Taken from the front and rear at the same time, they cannot win. Sixim, can you fire a rifle? One of these we captured?"

"I can. I have examined their mechanism."

"How is your aim?" It was a foolish question to ask.

"I hit what I aim at, every time."

"Then let us get close and get into positions. This may be our only chance. If we don't do it this time, there will probably be no second chance. Once they know we are out here, the guns will face both ways. Come, we have to get close now."

He moved out toward the enclosure, the Sixim, rifle slung, limping at his side. The Indians stayed where they were. He turned back to them, but they were as solid and unmoving as rock in their silence. Nothing more could be done. This left only the two of them, man and machine man, to do their best.

They were almost too late, While they were still twenty yards' from the palisade, sudden fire erupted from inside the building; the South Africans guns roared in return. Mark ran, drawing ahead of the Sixim, running through the open gate, to fall prone in the darkness near the wall and to control his breathing. To squeeze off his shots carefully.

One gunner fell, then another. Tie Sixim was beside him, firing at target after target with machine regularity. Someone had seen the muzzle blast of their guns, because weapons were turned on them, bullets tearing into the earth beside them, soldiers running toward them. Mark's gun clicked out of battery, empty of cartridges. He tore the empty clip away, struggled to jam in a full one; the soldier was above him.

Falling to one side with an arrow in his chest. Darker shadows moved, just as a solid wave of Sixim erupted through the open doorway.

That was the beginning of the end. As soon as they were among the soldiers, the slaughter began, no mercy, no quarter. Mark called the Indians to him, to the protection of their own battered Sixim, before they were also cut down. The carnage was brief and complete, and when it was over, a familiar one-eyed figure emerged from the building,

"Arinix," Mark called out, and the man turned and came over, "How did all this happen?"

"They were suspicious; they had been watching us for a long time. That officer we did not kill led them to this building." He said it without malice or regret, a statement of fact. Mark had no answer.

"Is this the last of them? Is the way open now?"

"There are more, but they will be eliminated. You see what happens when others attempt to control the way between the worlds?" He started away, then turned back. "Have you solved the problem with the Indians? Will they settle this world?"

"I think so. I would like to stay with them longer, give them what help I can."

"You do not wish to return to Einstein?"

That was a hard one to answer. Back to New York and the pollution and the life as a lawyer. It suddenly seemed a good deal emptier than it had. "I don't know. Perhaps, perhaps not. Let me finish here first."

Arinix turned away instantly and was gone. Mark went to Great Hawk, who sat cross-legged on' the ground and watched the operation with a great deal of interest. '

"Why did you and the others come to help?" Mark asked.

"It seemed too good a fight to miss. Besides, you said you would show us how to use the noise sticks. You could not do that if you were dead."

The smoke from the dying fires rose up in thin veils against the bright stars in the sky above. In his nostrils the air was cold and clean, its purity emphasized by the smell of wood smoke. Somewhere, not too far away, a wolf howled long and mournfully. This world, so recently empty of life, now had it in abundance, and would soon have human settlers as well, Indians of the Six Nations who would be escaping the fire that would destroy their own world. What sort of world would they make of it?

He had the sudden desire to see what would happen here, even to help in the shaping of it. The cramped life of a lawyer in a crowded world was without appeal. He had friends that he would miss, but he knew that new friends waited for him in the multiplicity of worlds he would soon visit. Really, there was no choice.

Arinix was by the open door issuing orders to the attentive Sixim. Mark called out to him.

The decision had really been an easy one.