The physics teacher, Howard Dax, dismissed the class. He picked up a felt-covered block and erased the diagrams he had drawn on the blackboard. He noticed with annoyance that the lines were shaky, and in one place was an irregular star where the chalk had broken because of his exasperation at his pupils—or more exactly, one particular pupil.

When the blackboard was clean to the corners—Howard Dax was a very precise man—he turned around and saw that the particular pupil was still sitting at his desk. He was a thin boy of fifteen, called Mallison, whose dark, wavy hair was too long. It rose in a kind of breaker over his forehead, and he had sideburns cut to a point. His expression was neither sullen nor impertinent, but Dax had always had the feeling that Mallison was concealing intense boredom and only listened to him perforce. He was sure that the narrow, rather handsome face was on the verge of sneering. But there had never been quite anything that he could put his finger on. The boy was definitely not good at physics, yet he wasn't at the bottom of the class. The thing was that he gave the impression of being above average intelligence. He obviously could do very much better if he wanted to. Dax was convinced that he despised physics, and school in general.

"Yes?" Dax said. "What is it?" He tried to make his voice sound natural and casual.

Mallison stared at him impassively for a moment. Then he said, "You don't like me, Mr. Dax, do you?"

"My dear boy, I neither like you nor dislike you," Dax said. He could feel his hands beginning again to tremble slightly. Damn adrenalin! "I am merely trying to teach you elementary physics. Why do you ask?"

"Why do you give me such low grades?" Mallison said, but with no sense of urgent curiosity.

Howard Dax thought that the boy's manner was altogether too adult. He didn't expect deference from a modern teenager, but neither did he like to be spoken to in such a man-to-man way. No; come to think of it, man-to-man wasn't quite the phrase. It was off-hand. And yet it was artificial: Mallison never spoke in this way to his contemporaries. He usually talked like a ... what was it? Hipster?

"I give students the grades that in my opinion they deserve," Dax said. "In your case they are low because I don't think you're trying."

"I am trying," Mallison said, then added, "sir."

"You are," Dax said. "Very." He thought the remark was rather neat, but the boy looked at him without any change of expression. Why was he here? What did he want to say? "I must confess," Dax went on, "that I am surprised at your interest in grades. I should have thought that rock-and-roll was more your style. That and ... er ... racing around at night in a fast car!" He felt that he was sneering, and made his face blank.

"I'm too young for a driver's license," Mallison said.

"But old enough to pull yourself together and do some real work. You could do much better in class. You're not stupid."

The boy said nothing and continued to stare at him without expression.

"When I see signs of an improved attitude," Dax said, "and a little more work, I shall mark you accordingly. One gets the impression usually that your mind is on other things. Things like jazz records."

"Didn't you listen to jazz when you were young, Mr. Dax?"

Howard Dax at thirty-nine hardly thought of himself as old. The boy was not being exactly fresh, but he had a sort of polite tactlessness. It was absurd, but he felt that Mallison had the upper hand, somehow.

Dax had an older brother who had been a lieutenant in World War II, and he had described to him an occasion on which he had interviewed an elderly staff sergeant. The staff sergeant in civilian life had been his brother's boss. Although his manner was scrupulously correct, there remained an atmosphere of his peacetime ascendancy. Howard Dax sympathized with his brother. There was nothing actually wrong with Mallison's manner, but the pupil had the master on the defensive.

He decided to ignore Mallison's question. He had no idea how the young nowadays felt about the subject of early Benny Goodman or the emergence of Barrel House. Why was he even bothering?

"The point at issue," he said with asperity, "is not whether I used to listen to jazz twenty-five years ago, but whether you are going to pay attention in class now. I admit you manage to scrape through in the tests, but this morning, for example, you acted as if you were half asleep!"

"I'm sorry. I was very tired." Mallison did look pale.

"I suppose you were up half the night—cutting a rug."

Mallison winced at the outdated jargon but he merely shook his head. There were firm steps in the corridor, and the school principal marched in.

Mallison stood up; Dax was still standing. The principal had a small piece of folded paper in his hand, and did not immediately notice the boy, whose desk was near the back row and next the open windows. He went straight to the platform and put the folded paper on Dax's desk. He nodded curtly and glanced towards the windows, and saw Mallison sitting there for the first time.

"I thought you were alone," he said, turning to Dax.

"You may go," Dax said to the boy. "That will be all. Remember what I said." He looked at the folded paper and then at the principal questioningly. "Yes, Mr. Lightstone?"

The principal was a short white-haired man with a dogged expression. He turned again to make sure the boy had left and said. "I want you to look at this, Dax." He tapped the folded paper, which had been made into a sort of envelope, with its ends tucked in. Dax bent to examine it.

"Pick it up, man! Open it," the principal said, and came around and sat in the teacher's chair. "Be careful not to spill it!"

Dax picked up the little packet and opened it. Inside was a teaspoonful of white powder. "What is it?" he asked.

"That," said the principal, "is something for our friends upstairs in the chemistry department to determine. I found it myself, in the flowerbed right outside these windows!"

Howard Dax looked puzzled. "I don't think I understand—"

"If I don't miss my bet," said the principal, "that's heroin!" He jerked his head towards the windows. "And somebody threw it out of this classroom!"

"Oh, I don't think it's heroin, Mr. Lightstone," Dax said. "Heroin has a distinct glitter, and this seems—"

"I had the impression you were a physicist, not a chemist," the principal said. "Besides, the police told us last week that they believe a gang of narcotics pushers—I think they called them—are operating in the neighborhood! What else could it be? I've been on the lookout for something of this sort."

There was a silence. Dax didn't know what to say.

He himself was very tired, he had been working late every evening. He had three different tasks that occupied every minute of his waking hours: his job as teacher being the least important although the most essential. The other two were perhaps visionary, but they might lead to something more exciting than retiring on a pension.

"Well?" Mr. Lightstone was impatient—his usual condition. "Have you any ideas? It has been my experience that drug-taking and juvenile delinquency go together." This was not strictly true as Mr. Lightstone had never knowingly seen a drug-taker, but he did read the papers.

"I suppose there is a certain amount of delinquency here," Howard Dax said uncertainly, "but narcotics...."

"Wake up, man!" the principal said. "You look half asleep! This is a serious matter. I found the stuff right outside these windows! You must have some idea of who might be involved. Which are the unruly ones? Who sits next the windows?"

Dax glanced at the desk recently left by Mallison. Mallison? One couldn't exactly call him unruly.... Yet he had the earmarks of a type he detested and instinctively mistrusted. He even feared him a little, though not perhaps for reasons of which he was quite aware.

"Who was that boy that just left?" The principal had noticed the direction of Dax's glance. "Mallison, wasn't it?"

"Yes, but the packet might just as well have been thrown from one of the paths outside."

"There's no path near here. You know that perfectly well," said the principal. "There's a wide stretch of grass beyond the flower bed and no one's allowed to walk on it! I've had my eye on that boy...."

Howard Dax thought this over. Come to think of it, he wouldn't put such a thing past the young smart-alec. Hoodlumism doesn't necessarily advertise itself in the classroom.

He looked at the principal. The man had a nerve to accuse him of seeming half asleep! Working in his private lab after dinner and then at his desk until all hours, struggling to learn Middle English—or rather, transitional Anglo-Saxon. He had done well at English lit at college, even though majoring in science, and Chaucer had come fairly easy to him. But Twelfth Century speech—and that was what he had to learn—was something else again. Chaucer himself couldn't have understood it. He wondered what young Mallison and his hipster friends would think if they knew his secret occupations. He could just imagine the sneering.

"Well, you could be right, I suppose," he said. "He's not my—shall I say?—favorite pupil."

"I'm glad you think I could be right," Mr. Lightstone said. "I intend to hold an investigation. At the first possible opportunity. This very evening, in fact. At my office, and I shall have young Mallison brought before us. I shall expect you." He got up and strutted out of the class room.

After a few moments Howard Dax followed him. Outside, on his way to the gate, he passed Mallison, who was standing talking to another boy who had a similar haircut, but was unfamiliar to the physics teacher. He thought he was not a pupil of this school. They both became silent as he drew near them, looking at him without any expression. Dax wondered if narcotics could be responsible for Mallison's pallor.

After dinner Dax went into his little lab, which was actually the kitchenette he never used. On the table and sink was some chemical apparatus. The principal's remark had been ill-chosen since Dax at college had started with chemistry as his major and had only switched to physics in his senior year. He had also become interested in genetics, and it was this all-around interest in the sciences that had perhaps militated against him. Nowadays one ought to specialize.

Well, he was specializing now.

In an evaporating dish in the sink were some dark brown crystals that his landlady would have taken for Damerara sugar, but which had a considerably more complex formula. They would have lent a rather odd flavor to Indian pudding. The logic which had given rise to this formula was not merely complex but revolutionary. It involved the concept of reversibility of entropy—the application of which was itself unprecedented.

There were, Howard Dax was aware, certain aspects of germ chemistry that defied description in terms of classical and mechanistic theory; details that seemed to require the inversion of Time's arrow. To say that a physical process was "non-reversible" usually implied the presence of the probability factor. But that didn't seem to be the case here. There was the suggestion of prophecy. Or else that time was flowing backwards. Or ... was it that something flowed backward through time?

Then there was the fact that the germ plasm was immortal. Not indestructible, for the overwhelming majority of zygotes and gametes died; but if one disregarded the soma, all living germ cells had been alive since the beginning of life. After terrific work, none of which would have seemed quite orthodox to his colleagues, Dax had arrived at the end of theory and the beginning of practical application—at the taking-off point—the countdown.

Lying on the drainboard near the evaporating dish was a hypodermic syringe.

If he were to dissolve the dark brown crystals and inject the solution into his veins, Dax believed that whatever it was that impeded this time-reversal would be neutralized. His consciousness—not his body, his somatic cells—would travel back along the unbroken line of his identity as a germinal continuity. Back to the extent that the effect of the chemical would allow.

He would then be in the body of one of his ancestors. Not spread among them all, but following the line of greatest genetic valence to one individual: living in the Twelfth Century A. D. Probably, but not certainly, somewhere in England, since most of his ancestors came from there.

Of course the time might be wrong. He had no way of making a precise determination. He had experimented with a rabbit, but after the soft little beast's eyes glazed over in unconsciousness it had immediately come to. The time taken during its visit to the purlieus of its remote and unknown forebears was of no duration in the present. And it had at once attacked him and bitten him savagely.

It seemed curious that an ancestral rabbit at a period not so very far back from a biological point of view should have a spirit so foreign to the rabbits of today. Perhaps the drug had overshot its mark....

What if that were to happen in his case? Wouldn't it perhaps take him to some earlier, non-human form and then, as it were, rebound to the precise moment in history that the strength of the drug indicated? A man is not a rabbit. But suppose he found himself not in the body of a Twelfth Century Englishman—a risky enough situation—but hanging by his tail from a tree in Java? How long before the hypothetical rebound to the time of the Plantagenets?

Howard Dax was too tired to concentrate on the problem: it was probably moonshine. The rabbit had been frightened, not atavistic.

The cumulative effect of overwork and irritation at the boy Mallison and the principal's manner had made him reckless and impatient. He made a sudden decision to stop worrying about precautions and take the plunge ... now.

He had plenty of time before the meeting. The trip to the past would have no duration in the present. He measured out an amount of distilled water and stirred the brown crystals into it with a glass rod. Then he filled the hypodermic and went into his bed-sittingroom.

He went to his desk and took a last look at a list of early English irregular verbs and lay down on his sofa, rolling up his sleeve.

He hardly felt the prick of the needle but he realized that the rather painful bump on his forehead had distracted his attention from it.

He looked at the thing he had bumped against. It was wooden and round in section, about as thick as his neck, and rose at a slight deviation from the vertical to a circular platform that was supported at other places by two more wooden uprights. Beyond and above was an immensely lofty roof of dark timbers. Far to the sides were stone walls.

He looked down to discover that the cold floor under him was also of stone, covered here and there with dry yellowish reeds. Then he saw that he was on all fours.

Instead of hands he had black, furry paws.

II

Trice, the jester, was getting old. So, he feared, were his jokes.

His joints were stiff and he could no longer do the amusing contortions that used so to entertain the Earl and his little court. In fact, the Earl was getting on, too. He looked as though he was falling asleep in his chair. Next to him the Lady Godwina was mumbling and giggling—not at poor Trice's feeble quips, but as a result of too much blackberry wine mixed with mead. She hiccoughed loudly and the Earl opened his eyes.

He glanced at the Lady Godwina with bored distaste, and then at Trice the jester. Would that the fellow would cease his tedious clowning and go to the kitchens! Yet he hesitated to get rid of him altogether. Having a jester at all in these days was a mark of prestige, and he didn't know where he'd get a replacement.

Now that King Henry was dead he had fortified his castle like the other barons. Since feudal pomp had become the fashion he hung onto its trappings—poor old Trice was one of them. But, ye gods, what stale jokes! Well, at least they seemed to please the younger serving men, who must be too young to remember them.

Trice was unhappily aware that his humor was missing the mark. He fell back on the one thing that never failed to make them laugh. He swung his bauble and hit himself on the nose. He staggered back with comic terror. "Hold on!" he cried to an imaginary assailant. "Not so hard!" He struck himself again, harder. "Stop! Or I shall appeal to my noble lord for protection!"

The Earl smiled faintly; he didn't want to disappoint the old man. Besides, his nose was bleeding. It really was rather funny. Curious about these people: they had almost no sense of pain. Trice, seeing the smile, hit himself again and again, and feeling the blood, he smeared it over his face in fantastic curlicues. The Earl closed his eyes again, and Trice caught the eye of the clerk, a young man who had come from Normandy. He was sneering. The Lady Godwina was singing a little tune to herself, and paid no attention.

The old jester shrugged, and turned towards the archway to the kitchens and offices. Better have supper and go to bed—his head ached and his nose hurt badly, although the bleeding had stopped. Next to a wooden stool he caught sight of his cat, Tybalt, staring at him fixedly. Tybalt. His only friend! he thought to himself. But as he passed him, the cat, instead of following him out with tail erect to share the jester's wretched supper, backed cringing under the stool and turned his head as he went by, keeping his staring eyes on him. Most unusual. Very un-catlike.

"Here! Tybalt!" Trice said, but the cat backed further away.

Just before he realized what had happened to him, Dax recognized that the big wooden thing that loomed over him was a stool.

Maybe it was this realization—and the sight of his own paws—that gave him an idea of his size, and on looking back at the rest of himself he knew that he was a cat. Something had gone wrong. The flashback and subsequent rebound must have taken him far into the dim mammalian past, but for what duration he could not tell. The transition had been unconscious. At least he did not remember it. But to judge by the style of the round stone arches of the hall he was now in—and the stonework looked brand new—the ultimate effect had been according to plan, and this was the early Middle Ages.

A movement caught his eye and he saw it was the cavorting of an enormous man, dressed in gigantic tattered motley.

No. He wasn't enormous; it was just the unfamiliar scale of things. The man was saying something in a booming voice, and Dax began to recognize it as a form of transitional early English—but with an admixture of Norman French and some pure Anglo-Saxon phrases. And what an accent! If this man was typical, how wrong modern research and learned speculation were! He would have some interesting things to tell the experts—particularly his tutor—when he got back.

When he got back.... That was supposed to be in three days approximately, when the inhibiting effect of the chemical would wear off. Then he would, he hoped, be swept back to his own time and his own body. But he was a cat. This was disastrous! How could he speak to people? He could understand them fairly well, but a cat's bucal cavity and vocal apparatus were not designed for the sounds of human speech.

He decided to try his voice, just on the chance, but stopped, horrified at the muffled yowl that resulted.

Two rangy hounds, six times his size, roused themselves from the rush-covered floor and glared growling at the sound with raised hackles. "Down, Colle! Stop it, Bayard!" a gruff voice commanded, and they reluctantly sank back again, keeping their fierce eyes on him. Was this a sample of what he must expect from dogs? He hoped it was merely his abortive attempt at human speech. Any further communication must be tried silently.

He looked around the hall. There were other humans too. Several men-at-arms standing by the walls and a few serving men. At the big trestle-board were seated five people—one of them clearly the lord of the castle—it must be a castle—and the one woman sitting next to him in soiled finery would be his lady. The place reeked with the stale odor of humans and dogs, and less obnoxiously the smell of wood smoke and cooked meat. Dax realized that he now had a feline nose, and made allowances. After all, the well-to-do bathed themselves, in the still existing classic tradition, and would until the Black Death.

The ridiculous giant in motley stopped his capering and came across the stone flags towards him. As he passed with ponderous footsteps he looked down and said, "Here, Tybalt!"

Dax backed under the stool, terrified at the deep, hoarse voice. The man was probably trying to be gentle. He must keep in mind that he had a cat's hearing now, and all sounds would seem lower and louder.

How were cats treated in Medieval England? He did not know, and he was not prepared for this contingency. But at least cats as a species had survived. He hoped he was one of the lucky ones. He must at all costs manage to keep alive for three days, because if he were killed before the drug wore off he would not return.

What would they think at the school? Nothing, of course. He would never have been there. That would be changing the future ... but you changed the future every time you exerted your free will, anyhow.

One of his experimental rats had not come back: it had merely disappeared with a loud pop. Perhaps an early Colonial terrier had got it. It might be the best thing to do to take to the woods, and wait out the time safe from the unknown dangers of men and dogs—but what of the dangers of the woods? It was winter, to judge by the fire in the hall, on a raised stone platform in the middle of the floor, from which the smoke found its way out through a louver in the high roof. And the icy drafts that came across the floor. Although he was a cat, he had little confidence of being able to hunt like one, or find refuge from the cold and snow.

He decided to follow the court jester. At least the man had spoken to him kindly. And he had a name: Tybalt. He must remember to answer to it.

He got up and began to walk towards the arched doorway through which the jester had disappeared.

Walking on all fours felt perfectly natural—rather as if he were following himself. There was no trouble about keeping in step, or, rather, just out of it. His mouth was dry and he ran his tongue over his muzzle ... he could lick his eye! Then he did something that also felt natural, though pleasantly novel: he waved his tail. Then he stuck out his claws. They clicked against the flagstones and he sheathed them again.

He had never in his life felt so supple and physically complete. He felt like running up the tapestry that hung by the doorway.

At the other end of the vaulted corridor that he found himself in he could see the jester as he went into another chamber that was lit with a smoky reddish glow. There was an increased smell of cookery, and he guessed it was the kitchen.

When he got to the door he could see the jester was being given something in a bowl that steamed, and a large hunk of dark bread. The man turned and came out again and saw him.

"Come along, Tybalt," he said. "Supper for you and me. Come along, old fellow!"

Dax followed him across the corridor to a narrow stone stairway in the thickness of the wall. The winding steps seemed absurdly high. He would far rather have done the whole thing in two or three long leaps, but he took the steps one by one. Feline coordination would come to him in time.

After an almost totally unlit passage they came to a minute room, scarcely more than a cell. The jester struck a light with flint and steel to a tallow candle, and sat down on a low straw-covered bed. The floor was freezing. Dax jumped up onto a small table, but was instantly pushed off it. His instinctive jump up and then down happened so quickly that he only realized in retrospect what a feat it was from a man's point of view. Yet he had landed clumsily. He was not yet quite a cat.

The jester cut off a piece of dubious-looking meat and threw it onto the floor. "Wait till it cools, Tybalt," he said, and scratched Dax behind the ears. Dax was ravenous, which seemed odd considering he'd had dinner half an hour ago. No, of course not. That was eight centuries in the future; God knew when Tybalt had last eaten. Disregarding the admonition he went at once to the meat, which was pork, and burned his mouth. It smelled glorious. And yet he suspected that in human form he would have revolted from it.

He looked up at his master. He had a conviction that he belonged to the jester.

He studied the gaunt, blood-smeared face. It looked as if someone had hit him on the nose. The cap-and-bells, with its attached wimple-shaped neck piece, had been laid aside. The gray bobbed hair and bony head looked anything but merry. There was, however, a shrewd reflective expression in the eyes, and Dax felt that he might well be in an advantageous position. Being a jester probably involved a certain amount of tact and discretion, not to mention ingenuity, so he resolved to try to communicate with him.

But first he must eat. Would the damned pork never cool?

The jester was already eating his, in great gulps, alternating it with bits of the evil-looking bread. There was a stoneware pot that smelled strongly of musty ale from which he drank every now and then. The stench of alcohol in it was like spoiled garbage to Dax. How had he ever been able to drink whisky? The thought of it was disgusting. The meat was cool enough now—in fact stone cold—and he tore it to pieces with his pointed teeth and bolted it unchewed. It was marvelous.

"Well, Tybalt?" the jester said, putting aside his bowl. "No mice today? We are not very lucky, we two, are we?" He made a snapping with his fingers and Dax jumped up onto the pallet beside him. The old man stroked his back gently, but he had a very strong smell. Dax supposed he would get used to his new keen senses in time. He hoped it would be soon. It was very cold in the jester's cell and he intended to creep close at bed time. In the meanwhile how was he going to make known his true identity? Obviously speech was impossible; and Morse-code tapping with his paw was out of the question.

You wouldn't get very far with mere facial expressions, either. Anyway, to most human eyes a cat has but two: contentment and fear. He looked around wondering if there were any small movable objects that he could arrange into the form of the letters of the alphabet—even a piece of string might do. But he feared that the man couldn't read. Anyway there was no string to be seen.

Then on the table, which was scarcely more than a high bench, he saw a rosary with wooden beads.

He got up and stretched—never in his life had he been able to stretch like this—and jumped delicately over onto the table. The jester reached out and swept him off it. Not roughly, but it was obvious he wasn't allowed there. This time his landing was more skillful. He sat on the cold floor and tried to think how he could get hold of the beads. If he had them on the floor he could push them into an arresting shape. A triangle perhaps, or a figure eight, that would catch the jester's eye. He looked up at a movement and saw that the man had picked up a small vellum book and was holding it close to his face. What luck! he could read after all! But how was he going to make letters? Near the sill of the door were some pieces of straw. He went over and examined them. He realized that a cat's vision is rather poor compared to a man's: quick to notice and interpret motion, but in other respects the over-large pupils, meant for nocturnal hunting, gave an inferior and uncertain image.

The straw was dirty and smelled of horses, but it ought to do. The trouble was that when his face was close enough to pick it up with his teeth he could scarcely make it out. He couldn't tell at first whether he had one or many in his mouth. He felt that his whiskers should tell him, but he was unaccustomed to their use. He padded over to the jester's feet and dropped the straws. He backed off and looked at them, then with his paw he ineptly pushed them into an A.

He looked up. The jester was lost in his reading.

Dax waited patiently, but the reading went on, and he patted the man's foot with carefully sheathed claws. The jester glanced at him, though not at the crude, straw A, and smiled.

"What now, Tybalt? More supper? That you will have to catch for yourself. See—it's all gone! Share-and-share alike, old friend. I weigh eight stone. You're but a scant four pound, so correspondingly...." He returned to his reading.

Dax went and picked out some more straw which he brought back and attempted to arrange in a B, but gave it up and made an E instead. Then he made two crosses and a triangle.

AEXXΔ.

It looked like a fraternity. Then he mewed.

The man looked down again with a faint frown. He didn't seem to notice the straw shapes; judging from the way he held the book he was quite short-sighted. "Out?" he asked. "Out for a rat, poor Tybalt? Or to lie by the embers in the hall?" He shook his head and got up, and went to the door to open it. Dax jumped onto the bed and mewed again. The man paused with his hand on the latch, looking puzzled. Dax jumped down and dabbed with his paw next each letter successively.

"Why, what is this?" the old man said, smiling again. "Playfulness? The kitten is back!" He went to the table and picking up the bauble, made a feint with the stuffed bladder over Dax's head. Dax dodged it irritably and mewed again; three times in quick succession.

This caught the attention of the jester, who laid down the bauble. "Ah! A Tritheist! Will it get you a mouse, Tybalt? Will it keep off evil spirits? It's said the imps love cats—so beware of moonlight and mistletoe!" He picked Dax up and stroked him.

It was infuriating.

Dax was aware that the Medieval mind was very different from the modern, but there must be some meeting point. Too bad this wasn't Friar Roger Bacon—he'd have got his attention in no time. But he was a hundred years too early. His immediate problem was to seek out some person who had enough imagination and curiosity to take notice of a cat who behaved not as a cat. If he had only known this was going to happen!

He tried mewing again, but the jester only smiled, so he mewed once, then twice and then three times. The jester shook his head admiringly. Like most of his contemporaries the world for him was filled with wonders. It was an age of faith, not of speculation.

A pale moon showed through a narrow slit in the wall, which was unglazed, and he became aware that the light from the tallow dip was yellow, and the jester's costume red and green.

So it was all nonsense about cats having no color vision—anyway, hadn't some woman in California disproved that? Against the moon he could see the black outline of full-grown leaves on the nearby trees and knew it was not yet winter but autumn. When winter came in earnest, everyone from scullion to the lord of the manor would bed down in the Great Hall where the fire was. But the stonework of the castle was cold, and he felt himself getting drowsy.

The old jester put down his book, crossed himself and blew out the light. Dax could hear him burrowing into the straw of his bed, and nestled beside him.

III

When he woke it was not quite dark, and a faint gray dawn came into the cell.

The jester was snoring. Somewhere Dax thought he heard a rat. His muscles tensed, and he found himself on his feet by instinct—the idea of a rat was surprisingly attractive and he was hungry again. The noise stopped. He remembered that he had been having a dream—a strange nightmare of chasing after Mallison and catching him, and tearing him ... with his claws and teeth.

A rusty bell started ringing somewhere in the castle.

The jester snorted, sat up and looked out of the narrow window. Then he lit the candle and said his prayers, kneeling on his bed. Dax stretched, and the old man cleaned his teeth with a splinter and took a draught from the ale pot. It had a sour stench, but Dax found that he no longer minded—there were so many conflicting smells around, the most interesting of which had been the rat. A new, more immediately hopeful one, was of cooking that drifted up from below. It seemed that these people ate meat for their breakfast. And they liked it early.

"Come along, Tybalt," the jester said, putting on his headdress, and went to the door. Dax slipped through quickly so as not to get his tail caught as the jester closed it. They went down the winding stairs again.

At the bottom they came upon another cat—a big red tom—who on catching sight of Dax fluffed his tail and laid back his ears, spitting. Dax had a momentary impulse to see if communication was possible with him, but the big cat yowled and fled down the hallway.

"Ah, Tybalt," the old man said. "Jesters and cats! Even their own kind spits at them!" As they got to the kitchen Dax saw the two hounds that had growled at him the night before. He was glad that they were now leashed and in the charge of a boy in a short woolen surcoat.

But when they saw Dax the boy was unable to hold them back, and they jerked their leashes from his hand and came running and barking. Dax was terrified. He bolted ahead of them along the vaulted corridor and into the Great Hall, but came face to face with another brace of hounds whose ears pricked up at the sound. Dax without any conscious thought dodged sideways and ran up the tapestry on the wall.

His sharp claws had good foothold on the tough canvas backing. But at the top he almost lost his grip, and scarcely managed to get over onto the musicians' gallery from which the tapestry hung. He crouched there, trembling, while the din below increased. He could hear men shouting at the dogs, and the jester's voice calling him. He mewed loudly for help.

After a while he heard the old man's footsteps on the wooden ladder. He was picked up and comforted, but he was so dizzy with fear that he could hardly see. The jester seemed to think he was calm, and put him on his shoulder and went down the ladder again. The hounds had been taken away. But Dax stayed where he was with his eyes shut, holding on tight.

"Well, Trice!" Dax opened his eyes and saw the lord of the manor glowering at the jester, and then at him. So Trice was the jester's name. An odd one. The Earl stood with his hands on his hips and seemed irritated rather than angry. "What's this I hear? The cat runs at my hounds and tries to scratch!"

"Oh, no, sir," Trice said. "It was the other way! They ran at him! Tybalt has never scratched!"

"Scratched or no, I wish you'd give him to one of the villagers," the Earl said. "I don't want the hounds upset, and Lady Godwina doesn't like cats. Besides, he'll ruin the tapestry."

"But, my lord, he catches the rats! And he's my ... friend."

"The dogs catch the rats," the Earl said shortly. "Give him away."

"Well, my lord, the mice...."

"The red tom gets them."

The old man put up a hand to Dax protectively. "But, noble lord, what would I do without my pet?" Dax glanced at the tired face next his and saw tears in the eyes, but he had a determined look. "If he cannot stay, I ... I must go, too!"

The Earl opened his eyes at this, but he smiled. "I see you are loyal, old Trice," he said. "I hope you are as loyal to me!"

The Earl turned away. Trice put Dax on the floor and started back towards the kitchens.

"Come, Tybalt," he said. "Or there'll be none left for us."

Dax wished he were still on the shoulder, and stayed close to the jester's feet. Things were not going well at all. It had become as much a problem of survival as of research and communication, but when they got to the kitchen and the hounds were nowhere about, he decided that perhaps the two problems were inter-related. After a meal of scraps he felt more secure. Not seeing his master he went to look for him in the Great Hall.

When he got there he saw that the Earl and his wife and retainers were eating boiled meat. He remembered that his tutor in Middle English had said the main meal in Medieval times was eaten in the morning. The four hounds were squabbling over bones that were thrown to them on the rush-covered flagstones under the trestle-board, and didn't notice him. Trice was not to be seen. After a while the boy in the woolen surcoat was told to take them out. He fastened leashes to their collars and led them through a large doorway in the far wall. Dax looked at the Earl: he had a fairly intelligent face, and he had shown forbearance towards Trice, so he thought he would make another try.

The Lady Godwina got up unsteadily from her chair and left the hall—on the way to the lady's solar, Dax guessed; and he padded across to the Earl. When he got to the foot of the high-backed chair—it looked like a detached choir-stall from a gothic church—he patted the Earl's foot.

The Earl looked down at him and frowned.

Dax patted the foot again; three times. Then he mewed three times, and repeated the patting. The Earl blinked and got up, backing away. Dax mewed three times again, and the Earl crossed himself.

"Saints preserve my soul! What have we here?"

Dax turned around three times, getting his hind legs crossed and nearly falling down. "Send for Trice at once!" the Earl shouted. "His cat Tybalt has a fit! Careful!" he said to a serving man who had come forward with outstretched hands. "Take care you are not bitten! He is unclean!"

Dax backed away and ran to the open door, and out.

There was a brilliant sun and he could see nothing at first—and when he did it was blurred, owing to the vertical shape of his contracted pupils. It was much warmer than the night before, and the leaves were brown on the trees. There was no courtyard and gateway, with drawbridge and moat beyond, as he had rather expected. Instead he was on cobblestones, surrounded at intervals by small houses, with trees between them. The village was built against the castle, somewhat in the French manner, but the houses were wretched affairs of mud-daubed reeds on wooden framing: hardly better than hovels. Only a few had more than one story. Smoke was coming up from every chimney, and the men were evidently on their way to work in the fields. They carried crude-looking farm implements and were dressed in coarse homespun with their legs padded and cross-gartered. They were a sorry lot: blank-faced and half starved.

Dax heard footsteps behind him and turned.

A young man with blond short hair and a Norman nose had come out of the doorway. He looked at Dax with amused curiosity, and squatted down, putting out a hand. At this proximity his eyes showed bloodshot and there was a beery smell. He said something that Dax could not understand—it sounded vaguely like a kind of French, but Dax had not studied medieval Norman. Still, it had a kindly sound. Dax rubbed against the hand. This man, at least, did not share the Earl's diagnosis. What was his position in the Earl's household? Not his son—he looked too unlike him. Would he be his clerk? He had a clerkly look—what is it in a face that makes it seem scholarly? And his hands were more fit for holding a pen than a mattock or a sword.

Well, give it another try.

Dax wished he could make an ingratiating sound, and found he was purring. He looked around for something he could use as a signal; mewing and tapping seemed to be misunderstood. A few yards away the cobblestones gave place to dirt, and he started towards it. It might do for a blackboard. He looked back, but the clerk had not moved.

Dax wondered how a cat might beckon, lacking a forefinger. He waited until he caught the young man's eye, and tried to beckon with his head but it had no results. He continued on to the patch of dirt and scratched a triangle, and to his relief the clerk got up and came to him. When he was standing over him, Dax scratched two words in Latin: homo sum, and looked up.

The clerk was staring with his mouth open.

Good, thought Dax: Latin was the lingua Franca of medieval Europe, and went on with his scratching. Humani nihil a me alienum—

There was a gasp and he looked up again. The young man had closed his eyes and had the back of his hand against his forehead. He turned and walked to the castle door, holding his head. Dax sat down in disgust. A Twelfth Century hangover, indeed! A shadow fell across him and he turned.

Three villagers: two men, and a woman in a hood were behind him. They had an expectant air, and, realizing that they were doubtless illiterate, he drew a large five-pointed star.

The effect on them was volcanic.

The woman screeched and threw her skirt over her head. The men crossed themselves and one of them turned and ran. The other slashed at Dax with a bill-hook and then, shouting, "Bewitched! Bewitched!" he, too, ran. The bill-hook missed Dax, thanks to his instinctive leap to one side, but the woman continued her noise and more people came out of the cottages, armed with farming implements and sticks. Everyone was shouting and offering advice. The main thread of their discourse was: Possessed! Possessed! Kill it! The Devil Incarnate!

Dax was hemmed in on three sides. He started back for the castle, but the big doorway was filled with onlookers, one of whom stepped forward, aiming a crossbow. There was a clank followed by a hissing in the air, and the bolt thumped into the ground next to him. The bowman cursed and began to wind up his bow with a crannikin. Dax's fur stood out all over him and he made a mad dash towards a group of women who had nothing in their hands but besoms of birch twigs. It was a fortunate choice.

Two or three women made abortive swats at him and the others backed away, leaving a clear path. In front of him was an open space and a tall tree.

Almost before he knew it he was near its top and the whole village was milling around near its base, looking up with red angry faces.

"Fire the tree!" someone shouted.

"T'won't burn. It's an elm!"

"Well, I shan't climb it!"

"I won't have my tree burn!" an indignant voice yelled, but was drowned out. Small children were jumping up and down in excitement, and some teen-age boys threw stones but none of them reached him. Dax spat furiously. Teen-agers were the same through the ages!

"Cut it down, then!"

"T'will fall on my house!" (A woman's voice.)

The shouting died down, and Dax hung on till his claws ached. There seemed to be a conference going on. The castle appeared to have lost interest, which relieved him; if there was to be any more crossbow shooting he stood little chance. After a short while the subject of the conference became apparent as men began arriving with bundles of dry sticks and faggots. To Dax's horror these were piled about the trunk and set alight. Then, as the flames began to rise, green boughs were added and a thick cloud of suffocating smoke came up.

Desperately he tried to find escape. One of the elm's long branches reached out almost over the roof of one of the houses, but it meant climbing down into the heart of the choking cloud. Beyond the house he suddenly caught sight of his master, Trice, who waved to him beseechingly. It gave him courage. Holding his breath, he began to back down the trunk until he felt the branch under him. Then he twisted round and ran along it with his heart pounding. A cat has small lungs for its size and holding his breath was a torment—but at last he was free of the smoke, and he took a breath of clean air.

The roof seemed to be within reach, and the crowd had temporarily lost sight of him in the smoke.

He could hear the jester's voice, but for some reason he couldn't understand him—it sounded like gibberish. He crept out until the thinning branch began to bend and, just as shouts went up from the more observant villagers, he leapt.

He landed on the thatch—and almost lost his hold, but he was just able to scramble to the rooftree, and ran along the ridge. There was more shouting. Either these ones spoke a dialect or the excitement had put Middle English out of his head: he could barely understand them. Something about Widow Aelthreda's cottage—something about a witch....

He slithered down the far side of the thatching and landed on a window box of late purple daisies. The parchment-covered window next him was open and he slipped inside just as the crowd turned the corner.

He found himself in a small, bare upstairs room, insufficiently lit by the single window, but he could easily see into the most profound shadows. Under a chest in the corner was a mouse, frozen with terror. Dax was still out of breath, but he crept toward it, and as it ran out along the baseboard he intercepted it. He ate it—all.

As he washed his face he wondered with diminishing nervousness what all the shouting and noise outside meant.

In a little while he heard footsteps and a woman came into the room. When she saw him she made some noises with her mouth, and Dax ran to her. She picked him up and began to stroke him very pleasantly. Then there were more noises from below and presently there were a lot of people in the room. The woman dropped him for some reason.

He ran under a big, low wooden thing, but a big iron thing was pushed at him. It had a sharp point, and he had to come out. This time the man with the bill-hook did not miss, but the pain lasted only for an instant.

And ... and ... he was more conscious of the sound made by the hypodermic as it fell on the floor and broke.

He looked at it with annoyance, and felt the slight prick on his arm. He got up and went to his bathroom, where he dabbed it with antiseptic. He saw that he'd better shave before going to the meeting. Well, the drug hadn't worked. What a waste of time. What a pity.

Perhaps a larger dose? He must experiment some more.

He started shaving.

IV

When he got to the principal's office—a little late, which was not entirely by accident—he found that Mallison and a few of his fellow-students were sitting opposite the desk in hard chairs.

The principal behind it gave Dax a reprimanding look, and then one at his watch. On one side of him were a group of teachers and a member of the school board who Dax remembered was Mr. Lightstone's especial crony. On the other were Mrs. Lightstone—a dour but subservient partner to her husband—and an empty chair.

The principal pointed to the chair and said, "We have been waiting for your arrival to begin, Mr. Dax." He turned to Mallison as Dax sat down, and said, "You are, I believe, what is known as a 'hep-cat'?" He waited but Mallison said nothing. His face was very white and he looked sullen. "Well, answer me, sir!" the principal said loudly.

"You didn't ask me anything," the boy said in a low voice. "You told me."

The principal pushed his lips out and breathed deeply. He took something from his pocket and held it up. Dax saw it was the packet of alleged heroin.

"Did you throw this out of the window of Mr. Dax's class room?"

The boy looked at it incomprehendingly and shook his head.

"Do you know what it is? Have you seen this packet before?"

"No, Mr. Lightstone...."

"You sound uncertain. Think carefully, Mallison." The principal put the packet on his desk and unfolded it. Everyone bent forward and looked at it—including Mallison, who shook his head again.

Dax leaned across Mrs. Lightstone and whispered to her husband, "Did you have it analyzed?"

The principal shook his head impatiently. "Not yet! There was no one in the Chemistry Department!" He cleared his throat importantly. "Well? What have you to say?"

Mallison apparently had nothing to say. He swallowed and looked at one of the boys next him. Mr. Lightstone leaned back in his chair and turned to address the group on his right—the school board man in particular. "This," he said, tapping the packet, "was thrown out of a window of the physics class room today. These are the boys that sit next those windows. I have every reason to suspect Mallison."

The group nodded. Dax realized that they had been briefed in advance. The boy Mallison had certainly a sulky and uncooperative air. He seemed the epitome of juvenile delinquency on the defensive, and yet....

"You," the principal said to the boys, "are a little band of trouble-makers. You cut classes, you stay up late and go to what I believe you call juke-joints. I have heard reports of your riding in hot-rods!" He paused significantly.

"None of us here's got a car," Mallison said in a flat voice. He was definitely sneering now. "I've never even seen a real drag-race!"

Mr. Lightstone blinked. The word was unfamiliar to him, but it had a disreputable ring to it. "And I suppose you've never taken narcotics?"

There was a dead silence. Mallison clamped his mouth shut, and his face became wooden.

Mr. Lightstone addressed the boy next him. "Have you ever seen any of the boys use this?" He tapped the packet again. "Did you see Mallison throw it out of the window? You sit behind him!"

The boy looked blank and glanced at Mallison. "No, sir," he said.

"But you couldn't have missed seeing him!"

"Excuse me a minute," Dax said. "These boys aren't a band exactly. They just happen to sit next the windows."

Mr. Lightstone looked offended but resourceful. "They picked those seats themselves. That's what a clique does. It—"

"I assign all the pupils to their desks," Dax said, and felt he was turning pink.

The principal took this in his stride by ignoring it. "And you," he said to the boy on Mallison's other side. "What have you to say?"

The boy frowned and stuttered.

Dax was beginning to feel annoyed although he didn't know exactly why. For one thing, he had let himself seem to be defending Mallison. It was his craze for accuracy, of course. "I don't understand why the parents of these boys aren't here," he was surprised to hear himself say. "It seems to me they ought to have some kind of defense counsel if there is going to be a trial."

The principal looked at him steadily. "Would you care to act in that capacity?"

Dax felt that he was getting redder than ever. "Have you had a doctor examine Mallison for ... for the effects of narcotics?" he said. "Where are these policemen you said you spoke to? Shouldn't they be informed of your suspicions, instead of holding a kind of star chamber inquisition? It's ... it's medieval!"

Mr. Lightstone glared at him in astonishment.

Dax had a sudden thought. "The chemistry lab is right over my class room," he said. "Why couldn't the packet have fallen from there?"

"What would they be doing with heroin?"

"But we don't know yet that—"

The principal interrupted him and swept his arm in a gesture of all-inclusive condemnation. "We will in good time! But if you have never seen guilt before, you see it now!" He looked at the startled young faces with abhorrence. "Look at them!"

Dax had a curious and violent revulsion, although he hadn't followed the line of reasoning in Lightstone's last remark. In fact, he realized that he hadn't really heard the words. But the principal's angry face made his hackles rise.

The principal had a menacing look. He was the most dangerous looking thing he had ever seen. A convulsive shudder went through all of Dax's muscles, and he leapt—straight across Mrs. Lightstone's lap, who fell over backwards, screaming. Everyone was making loud, garbled noises, and he was on top of Lightstone, scratching and biting.

He heard himself give a loud, warlike and triumphant yowl.