The year was 750 AA (Ante Atomic) or 1200 AD (Anno Domini), approximately. Hanville Svetz stepped out of the extension cage and looked about him.

To Svetz the atomic bomb was eleven hundred years old and the horse was a thousand years dead. It was his first trip into the past. His training didn't count; it had not included actual time-travel, which cost several million commercials a shot. Svetz was groggy from the peculiar gravitational side-effects of time-travel. He was high on pre-industrial-age air, and drunk on his own sense of destiny; while at the same time he was not really convinced that he had gone anywhere. Or anywhen. Trade joke.

He was not carrying the anesthetic rifle. He had come to get a horse; he had not expected to meet one at the door. How big was a horse? Where were horses found? Consider what the institute had had to go on: a few pictures in a salvaged children's book, and an old legend, not to be trusted, that the horse had once been used as a kind of animated vehicle!

In an empty land beneath an overcast sky, Svetz braced himself with one hand on the curved flank of the extension cage. His head was spinning. It took him several seconds to realize that he was looking at a horse.

It stood fifteen yards away, regarding Svetz with large intelligent brown eyes. It was much larger than he had expected. Further, the horse in the picture book had had a glossy brown pelt with a short mane, while the beast now facing Svetz was pure white, with a mane that flowed like a woman's long hair. There were other differences... but no matter, the beast matched the book too well to be anything but a horse.

To Svetz it seemed that the horse watched him, waited for him to realize what was happening. Then, while Svetz wasted more time wondering why he wasn't holding a rifle, the horse laughed, turned and departed. It disappeared with astonishing speed.

Svetz began to shiver. Nobody had warned him that the horse might have been sentient! Yet the beast's mocking laugh had sounded far too human.

Now he knew. He was deep, deep in the past.

Not even the horse was as convincing as the emptiness the horse had left behind. No reaching apartment towers clawed the horizon. No contrails scratched the sky. The world was trees and flowers and rolling grassland, innocent of men.

The silence - It was as if Svetz had gone deaf. He had heard no sound since the laughter of the horse. In the year 1100, Post Atomic, such silence could have been found nowhere on Earth. Listening, Svetz knew at last that he had reached the British Isles before the coming of civilization. He had traveled in time.

The extension cage was the part of the time machine that did the traveling. It had its own air supply, and needed it while being pushed through time. But not here. Not before civilization's dawn; not when the air had never been polluted by fission wastes and the combustion of coal, hydrocarbons, tobaccos, wood, et al.

Now, retreating in panic from that world of the past to the world of the extension cage, Svetz nonetheless left the door open behind him.

He felt better inside the cage. Outside was an unexplored planet, made dangerous by ignorance. Inside the cage it was no different from a training mission. Svetz had spent hundreds of hours in a detailed mock-up of this cage, with a computer running the dials. There had even been artificial gravity to simulate the peculiar side-effects of motion in time.

By now the horse would have escaped. But he now knew its size, and he knew there were horses in the area. To business, then.

Svetz took the anesthetic rifle from where it was clamped to the wall. He loaded it with what he guessed was the right size of soluble crystalline anesthetic needle. The box held several different sizes, the smallest of which would knock a shrew harmlessly unconscious, the largest of which would do the same for an elephant. He slung the rifle and stood up.

The world turned grey. Svetz caught a wall clamp to stop himself from falling.

The cage had stopped moving twenty minutes ago. He shouldn't still be dizzy! - But it had been a long trip. Never before had the Institute for Temporal Research pushed a cage beyond zero PA. A long trip and a strange one, with gravity pulling Svetz's mass uniformly toward Svetz's navel.

When his head cleared, he turned to where other equipment was clamped to a wall.

The flight stick was a lift-field generator and power source built into five feet of pole, with a control ring at one end, a brush discharge at the other, and a bucket seat and seat belt in the middle. Compact even for Svetz's age, the flight stick was a spin-off from the spaceflight industries.

But it still weighed thirty pounds with the motor off. Getting it out of the clamps took all his strength. Svetz felt queasy, very queasy.

He bent to pick up the flight stick, and abruptly realized that he was about to faint.

He hit the door button and fainted.







"We don't know where on Earth you'll wind up", Ra Chen had told him. Ra Chen was the Director of the Institute for Temporal Research, a large round man with gross, exaggerated features and a permanent air of disapproval. "That's because we can't focus on a particular time of day - or on a particular year, for that matter. You won't appear underground or inside anything because of energy considerations. If you come out a thousand feet in the air, the cage won't fall; it'll settle slowly, using up energy with a profligate disregard for our budget..."

And Svetz had dreamed that night, vividly. Over and over his extension cage appeared inside solid rock, exploded with a roar and a blinding flash.

"Officially, the horse is for the Bureau of History", Ra Chen had said. "In practice it's for the Secretary-General, for his twenty-eighth birthday. Mentally he's about six years old, you know. The royal family's getting a bit inbred these days. We managed to send him a picture book we picked up in 130 PA, and now the lad wants a horse..."

Svetz had seen himself being shot for treason, for the crime of listening to such talk.

"... Otherwise we'd never have gotten the appropriation for this trip. It's in a good cause. We'll do some cloning from the horse before we send the original to the UN. Then - well, genes are a code, and codes can be broken. Get us a male, and we'll make all the horses anyone could want."

But why would anyone want even one horse? Svetz had studied a computer duplicate of the child's picture book that an agent had pulled from a ruined house a thousand years ago. The horse did not impress him.

Ra Chen, however, terrified him.

"We've never sent anyone this far back", Ra Chen had told him the night before the mission, when it was too late to back out with honor. "Keep that in mind. If something goes wrong, don't count on the rule book. Don't count on your instruments. Use your head. Your head, Svetz. God knows it's little enough to depend on..."

Svetz had not slept in the hours before departure.

"You're scared stiff", Ra Chen commented just before Svetz entered the extension cage. "And you can hide it, Svetz. I think I'm the only one who's noticed. That's why I picked you, because you can be terrified and go ahead anyway. Don't come back without a horse..."

The director's voice grew louder. "Not without a horse, Svetz. Your head, Svetz, your HEAD..."

Svetz sat up convulsively. The air! Slow death if he didn't close the door! But the door was closed, and Svetz was sitting on the floor holding his head, which hurt.

The air system had been transplanted, complete with dials, intact from a Martian sandboat. The dials read normally, of course, since the cage was sealed.

Svetz nerved himself to open the door. As the sweet, rich air of twelfth-century Britain rushed in, Svetz held his breath and watched the dials change. Presently he closed the door and waited, sweating, while the air system replaced the heady poison with its own safe, breathable mixture.







When next he left the extension cage, carrying the flight stick, Svetz was wearing another spin-off from the interstellar-exploration industries. It was a balloon, and he wore it over his head. It was also a selectively permeable membrane, intended to pass certain gasses in and others out, to make a breathing-air mixture inside.

It was nearly invisible except at the rim. There, where light was refracted most severely, the balloon showed as a narrow golden circle enclosing Svetz's head. The effect was not unlike a halo as shown in medieval paintings. But Svetz didn't know about medieval paintings.

He wore also a simple white robe, undecorated, constricted at the waist, otherwise falling in loose folds. The institute thought that such a garment was least likely to violate taboos of sex or custom. The trade kit dangled loose from his sash: a heat-and-pressure gadget, a pouch of corundum, small phials of additives for color.

Lastly he wore a hurt and baffled look. How was it that he could not breath the clean air of his own past?

The air of the cage was the air of Svetz's own time, and was nearly four percent carbon dioxide. The air of 750 Ante Atomic held barely a tenth of that. Man was a rare animal here and now. He had breathed little air, he had destroyed few forests, he had burnt scant fuel since the dawn of time.

But industrial civilization meant combustion. Combustion meant carbon dioxide thickening in the atmosphere many times faster than the green plants could turn it back to oxygen. Svetz was at the far end of two thousand years of adaptation to air rich in CO2.

It takes a concentration of carbon dioxide to trigger the autonomic nerves in the lymph glands in a man's left armpit. Svetz had fainted because he wasn't breathing.

So now he wore a balloon, and felt rejected.

He straddled the flight stick and twisted the control knob on the fore end. The stick lifted under him, and he wriggled into place on the bucket seat. He twisted the knob further.

He drifted upward like a toy balloon.

He floated over a lovely land, green and untenanted, beneath a pearl-grey sky empty of contrails. Presently he found a crumbling wall. He turned to follow it.

He would follow the wall until he found a settlement. If the old legend was true - and, Svetz reflected, the horse had certainly been big enough to drag a vehicle - then he would find horses wherever he found men.

Presently it became obvious that a road ran along the wall. There the dirt was flat and bare and consistently wide enough for a walking man; whereas elsewhere the land rose and dipped and tilted. Hard dirt did not a freeway make; but Svetz got the point.

He followed the road, floating at a height of ten meters. There was a man in worn brown garments. Hooded and barefoot, he walked the road with patient exhaustion, propping himself with a staff. His back was to Svetz.

Svetz thought to dip toward him to ask concerning horses. He refrained. With no way to know where the cage would alight, he had learned no ancient languages at all.

He thought of the trade kit he carried, intended not for communication, but instead of communication. It had never been field-tested. In any case it was not for casual encounters. The pouch of corundum was too small.

Svetz heard a yell from below. He looked down in time to see the man in brown running like the wind, his staff forgotten, his fatigue likewise.

"Something scared him," Svetz decided. But he could see nothing fearful. Something small but deadly, then.

The institute estimated that man had exterminated more than a thousand species of mammal and bird and insect - some casually, some with malice - between now and the distant present. In this time and place there was no telling what might be a threat. Svetz shuddered. The brown man with the hairy face might well have run from a stinging thing destined to kill Hanville Svetz.

Impatiently Svetz upped the speed of his flight stick. The mission was taking far too long. Who would have guessed that centers of population would have been so far apart?







Half an hour later, shielded from the wind by a paraboloid force-field, Svetz was streaking down the road at sixty miles per hour.

His luck had been incredibly bad. Wherever he had chanced across a human being, that person had been just leaving the vicinity. And he had found no centers of population.

Once he had noticed an unnatural stone outcropping high on a hill. No law of geology known to Svetz could have produced such an angular, flat-sided monstrosity. Curious, he had circled above it - and had abruptly realized that the thing was hollow, riddled with rectangular holes.

A dwelling for men? He didn't want to believe it. Living within the hollows of such a thing would be like living underground. But men tend to build at right angles, and this thing was all right angles.

Below the hollowed stone structure were rounded, hairy-looking hummocks of dried grass, each with a man-sized door. Obviously they must be nests for very large insects. Svetz had left that place quickly.

The road rounded a swelling green hill ahead of him. Svetz followed, slowing.

A hilltop spring sent a stream bubbling down the hill to break the road. Something large was drinking at the stream.

Svetz jerked to a stop in midair. Open water: deadly poison. He would have been hard put to say which had startled him more: the horse, or the fact that it had just committed suicide.

The horse looked up and saw him.

It was the same horse. White as milk, with a flowing abundance of snowy mane and tail, it almost had to be the horse that had laughed at Svetz and run. Svetz recognized the malignance in its eyes, in the moment before it turned its back.

But how could it have arrived so fast?

Svetz was reaching for the gun when the situation turned upside down.

The girl was young, surely no more than sixteen. Her hair was long and dark and plaited in complex fashion. Her dress, of strangely stiff blue fabric, reached from her neck to her ankles. She was seated in the shadow of a tree, on dark cloth spread over the dark earth. Svetz had not noticed her, might never have noticed her.

But the horse walked up to her, folded its legs in alternate pairs, and laid its ferocious head in her lap.

The girl had not yet seen Svetz.

"Xenophilia!" Svetz snarled the worst word he could think of. Svetz hated aliens.

The horse obviously belonged to the girl. He could not simply shoot it and take it. It would have to be purchased... somehow.

He needed time to think! And there was no time, for the girl might look up at any moment. Baleful brown eyes watched him as he dithered.

He dared waste no more time searching the countryside for a wild horse. There was an uncertainty, a Finagle factor in the math of time-travel. It manifested itself as an uncertainty in the energy of a returning extension cage, and it increased with time. Let Svetz linger too long, and he could be roasted alive in the returning cage.

Moreover, the horse had drunk open water. It would die, and soon, unless Svetz could return it to 1100 Post Atomic. Thus the beast's removal from this time could not change the history of Svetz's own world. It was a good choice... if he could conquer his fear of the beast.

The horse was tame. Young and slight as she was, the girl had no trouble controlling it. What was there to fear?

But there was its natural weaponry... of which Ra Chen's treacherous picture book had shown no sign. Svetz surmised that later generations routinely removed it before the animals were old enough to be dangerous. He should have come a few centuries later.

And there was the look in its eye. The horse hated Svetz, and it knew Svetz was afraid.

Could he shoot it from ambush?

No. The girl would worry if her pet collapsed without reason. She would be unable to concentrate on what Svetz was trying to tell her.

He would have to work with the animal watching him. If the girl couldn't control it - or if he lost her trust - Svetz had little doubt that the horse would kill him.







The horse looked up as Svetz approached, but made no other move. The girl watched too, her eyes round with wonder. She called something that must have been a question.

Svetz smiled back and continued his approach. He was a foot above the ground, and gliding at dead slow. Riding the world's only flying machine, he looked impressive as all hell, and knew it.

The girl did not smile back. She watched warily. Svetz was within yards of her when she scrambled to her feet.

He stopped the flight stick at once and let it settle. Smiling placatorially, he removed the heat-and-pressure device from his sash. He moved with care. The girl was on the verge of running.

The trade kit was a pouch of corundum, A1203, several phials of additives, and the heat-and-pressure gadget. Svetz poured corundum into the chamber, added a dash of chromic oxide, and used the plunger. The cylinder grew warm. Presently Svetz dropped a pigeon's-blood star ruby into his hand, rolled it in his fingers, held it to the sun. It was red as dark blood, with a blazing white six-pointed star.

It was almost too hot to hold.

Stupid! Svetz held his smile rigid. Ra Chen should have warned him! What would she think when she felt the gem's unnatural heat? What trickery would she suspect?

But he had to chance it. The trade kit was all he had.

He bent and rolled the gem to her across the damp ground. She stooped to pick it up. One hand remained on the horse's neck, calming it. Svetz noticed the rings of yellow metal around her wrist, and he also noticed the dirt.

She held the gem high, looked into its deep red fire.

"Ooooh", she breathed. She smiled at Svetz in wonder and delight. Svetz smiled back, moved two steps nearer, and rolled her a yellow sapphire.







How had he twice chanced on the same horse? Svetz never knew. But he soon knew how it had arrived before him.

He had given the girl three gems. He held three more in his hand while he beckoned her onto the flight stick. She shook her head; she would not go. Instead she mounted the animal.

She and the horse, they watched Svetz for his next move.

Svetz capitulated. He had expected the horse to follow the girl while the girl rode behind him on the flight stick. But if they both followed Svetz, it would be the same.

The horse stayed to one side and a little behind Svetz's flight stick. It did not seem inconvenienced by the girl's weight. Why should it be? It must have been bred for the task. Svetz notched his speed higher, to find how fast he could conveniently move.

Faster he flew, and faster. The horse must have a limit.

He was up to eight before he quit. The girl lay flat along the animal's back, hugging its neck to protect her face from the wind. But the horse ran on, daring Svetz with its eyes.

How to describe such motion? Svetz had never seen ballet. He knew how machinery moved, and this wasn't it. All he could think of was a man and a woman making love. Slippery-smooth rhythmic motion, absolute single-minded purpose, motion for the pleasure of motion. It was terrible in its beauty, the flight of the horse.

The word for such running must have died with the horse itself.

The horse would never have tired, but the girl did. She tugged on the animal's mane, and it stopped. Svetz gave her the jewels he held, made four more and gave her one.

She was crying from the wind, crying and smiling as she took the jewels. Was she smiling for the jewels, or for the joy of the ride? Exhausted, panting, she lay with her back against the warm, pulsing flank of the resting animal. Only her hand moved, as she ran her fingers repeatedly through its silver mane. The horse watched Svetz with malevolent brown eyes.

The girl was homely. It wasn't just the jarring lack of makeup. There was evidence of vitamin starvation. She was short, less than five feet in height, and thin. There were marks of childhood disease. But happiness glowed behind her homely face, and it make her almost passable, as she clutched the corundum stones.

When she seemed rested, Svetz remounted. They went on.

He was almost out of corundum when they reached the extension cage. There it was that he ran into trouble.

The girl had been awed by Svetz's jewels, and by Svetz himself, possibly because of his height or his ability to fly. But the extension cage scared her. Svetz couldn't blame her. The side with the door in it was no trouble: just a seamless spherical mirror. But the other side blurred away in a direction men could not visualize. It had scared Svetz spitless the first time he saw the time machine in action.

He could buy the horse from her, shoot it here and pull it inside, using the flight stick to float it. But it would be so much easier if...

It was worth a try. Svetz used the rest of his corundum. Then he walked into the extension cage, leaving a trail of colored corundum beads behind him.

He had worried because the heat-and-pressure device would not produce facets. The stones all came out shaped like miniature hen's eggs. But he was able to vary the color, using chromic oxide for red and ferric oxide for yellow and titanium for blue; and he could vary the pressure planes, to produce cat's eyes or star gems at will. He left a trail of small stones, red and yellow and blue. .

And the girl followed, frightened, but unable to resist the bait. By now she had nearly filled a handkerchief with the stones. The horse followed her into the extension cage.

Inside, she looked at the four stones in Svetz's hand: one of each color, red and yellow and light blue and black, the largest he could make. He pointed to the horse, then to the stones.

The girl agonized. Svetz perspired. She didn't want to give up the horse... and Svetz was out of corundum.

She nodded, one swift jerk of her chin. Quickly, before she could change her mind, Svetz poured the stones into her hand. She clutched the hoard to her bosom and ran out of the cage, sobbing.

The horse stood up to follow.

Svetz swung the rifle and shot it. A bead of blood appeared on the animal's neck. It shied back, then sighted on Svetz along its natural bayonet.

Poor kid, Svetz thought as he turned to the door. But she'd have lost the horse anyway. It had sucked polluted water from an open stream. Now he need only load the flight stick aboard.

Motion caught his eye.

A false assumption can be deadly. Svetz had not waited for the horse to fall. It was with something of a shock that he realized the truth. The beast wasn't about to fall. It was about to spear him like a cocktail shrimp.

He hit the door button and dodged.

Exquisitely graceful, exquisitely sharp, the spiral horn slammed into the closing door. The animal turned like white lightning in the confines of the cage, and again Svetz leapt for his life.

The point missed him by half an inch. It plunged past him and into the control board, through the plastic panel and into the wiring beneath.

Something sparkled and something sputtered.

The horse was taking careful aim, sighting along the spear in its forehead. Svetz did the only thing he could think of. He pulled the home-again lever.

The horse screamed as it went into free fall. The horn, intended for Svetz's navel, ripped past his ear and tore his breathing-balloon wide open.

Then gravity returned; but it was the peculiar gravity of an extension cage moving forward through time. Svetz and the horse were pulled against the padded walls. Svetz sighed in relief.

He sniffed again in disbelief. The smell was strong and strange, like nothing Svetz had ever smelled before. The animal's terrible horn must have damaged the air plant. Very likely he was breathing poison. If the cage didn't return in time...

But would it return at all? It might be going anywhere, any-when, the way that ivory horn had smashed through anonymous wiring. They might come out at the end of time, when even the black infrasuns gave not enough heat to sustain life.

There might not even be a future to return to. He had left the flight stick. How would it be used? What would they make of it, with its control handle at one end and the brush-style static discharge at the other and the saddle in the middle? Perhaps the girl would try to use it. He could visualize her against the night sky, in the light of a full moon... and how would that change history?

The horse seemed on the verge of apoplexy. Its sides heaved, its eyes rolled wildly. Probably it was the cabin air, thick with carbon dioxide. Again, it might be the poison the horse had sucked from an open stream.

Gravity died. Svetz and the horse tumbled in free fall, and the horse queasily tried to gore him.

Gravity returned, and Svetz, who was ready for it, landed on top. Someone was already opening the door.

Svetz took the distance in one bound. The horse followed, screaming with rage, intent on murder. Two men went flying as it charged out into the institute control center.

"It doesn't take anesthetics!" Svetz shouted over his shoulder. The animal's agility was hampered here among the desks and lighted screens, and it was probably drunk on hyperventilation. It kept stumbling into desks and men. Svetz easily stayed ahead of the slashing horn.

A full panic was developing.







"We couldn't have done it without Zeera", Ra Chen told him much later. "Your idiot tanj horse had the whole center terrorized. All of a sudden it went completely tame, walked up to that frigid bitch Zeera and let her lead it away."

"Did you get it to the hospital in time?"

Ra Chen nodded gloomily. Gloom was his favorite expression and was no indication of his true feelings. "We found over fifty unknown varieties of bacteria in the beast's bloodstream. Yet it hardly looked sick! It looked healthy as a, healthy as a... it must have tremendous stamina. We managed to save not only the horse, but most of the bacteria too, for the Zoo."

Svetz was sitting up in a hospital bed, with his arm up to the elbow in a diagnostician. There was always the chance that he too had located some long-extinct bacterium. He shifted uncomfortably, being careful not to move the wrong arm, and asked, "Did you ever find an anesthetic that worked?".

"Nope. Sorry about that, Svetz. We still don't know why your needles didn't work. The tanj horse is simply immune to tranks of any kind. Incidentally, there was nothing wrong with your air plant. You were smelling the horse."

"I wish I'd known that. I thought I was dying."

"It's driving the internes crazy, that smell. And we can't seem to get it out of the center." Ra Chen sat down on the edge of the bed. "What bothers me is the horn on its forehead. The horse in the picture book had no horns."

"No, sir."

"Then it must be a different species. It's not really a horse, Svetz. We'll have to send you back. It'll break our budget, Svetz."

"I disagree, sir-"

"Don't be so tanj polite."

"Then don't be so tanj stupid, sir." Svetz was not going back for another horse. "People who kept tame horses must have developed the habit of cutting off the horn when the animal was a pup. Why not? We all saw how dangerous that horn is. Much too dangerous for a domestic animal."

"Then why does our horse have a horn?"

"That's why I thought it was wild, the first time I saw it. I suppose they didn't start cutting off horns until later in history."

Ra Chen nodded in gloomy satisfaction. "I thought so too. Our problem is that the Secretary-General is just barely bright enough to notice that his horse has a horn, and the picture book horse doesn't. He's bound to blame me."

"Mmm." Svetz wasn't sure what was expected of him.

"I'll have to have the horn amputated."

"Somebody's bound to notice the scar", said Svetz.

"Tanj it, you're right. I've got enemies at court. They'd be only too happy to claim I'd mutilated the Secretary-General's pet." Ra Chen glared at Svetz. "All right, let's hear your idea."

Svetz was busy regretting. Why had he spoken? His vicious, beautiful horse, tamely docked of its killer horn... he had found the thought repulsive. His impulse had betrayed him. What could they do but remove the horn?

He had it. "Change the picture book, not the horse. A computer could duplicate the book in detail, but with a horn on every horse. Use the center computer, then wipe the tape afterward."

Morosely thoughtful, Ra Chen said, "That might work. I know someone who could switch the books." He looked up from under bushy black brows. "Of course, you'd have to keep quiet."

"Yes, sir."

"Don't forget." Ra Chen got up. "When you get out of the diagnostician, you start a four weeks vacation."







"I'm sending you back for one of these," Ra Chen told him four weeks later. He opened the bestiary. "We picked up the book in a public park around ten Post Atomic; left the kid who was holding it playing with a carborundum egg."

Svetz examined the picture. "That's ugly. That's really ugly. You're trying to balance the horse, right? The horse was so beautiful, you've got to have one of these or the universe goes off balance."

Ra Chen closed his eyes in pain. "Just go get us the Gila monster, Svetz. The Secretary-General wants a Gila monster."

"How big is it?"

They both looked at the illustration. There was no way to tell.

"From the looks of it, we'd better use the big extension cage."







Svetz barely made it back that time. He was suffering from total exhaustion and extensive second-degree burns. The thing he brought back was thirty feet long, had vestigial bat-like wings, breathed fire, and didn't look very much like the illustration; but it was as close as anything he'd found.

The Secretary-General loved it.












In my archives, I have a PDF copy of the book "The Flight of the Horse" by Larry Niven, which contains the story of the same name along with various others.

Details from the PDF:
- A Del Rey Book, Published by Ballantine Books, Copyright (c) 1973 by Larry Niven
- Parts of this book were previously published:
-- The Flight of the Horse, Fantasy and Science Fiction, (c) 1969 by Mercury Press, Inc.

I have treated the text in the PDF as my authoritative copy, although I have made some corrections / adjustments to the text where it seemed appropriate.