There was the usual, entirely normal crowd on the expressway: the standees on the lower level and those with seat privileges above. A continuous trickle of humanity filtered off the expressway, across the decelerating strips to localways or into the stationaries that led under arches or over bridges into the endless mazes of the City Sections. Another trickle, just as continuous, worked inward from the other side, across the accelerating strips and onto the expressway.

There were the infinite lights: the luminous walls and ceilings that seemed to drip cool, even phosphorescence; the flashing advertisements screaming for attention; the harsh, steady gleam of the "lightworms" that directed,

THIS WAY TO JERSEY SECTIONS, FOLLOW ARROWS TO EAST RIVER SHUTTLE, UPPER LEVEL FOR ALL WAYS TO LONG ISLAND SECTIONS

Most of all there was the noise that was inseparable from life: the sound of millions talking, laughing, coughing, calling, humming, breathing.

No directions anywhere to Spacetown, thought Baley.

He stepped from strip to strip with the ease of a lifetime's practice. Children learned to "hop the strips" as soon as they learned to walk. Baley scarcely felt the jerk of acceleration as his velocity increased with each step. He was not even aware that he leaned forward against the force. In thirty seconds he had reached the final sixty-mile-an-hour strip and could step aboard the railed and glassed-in moving platform that was the expressway.

No directions to Spacetown, he thought.

No need for directions. If you've business there, you know the way. If you don't know the way, you've no business there. When Spacetown was first established some twenty-five years earlier, there was a strong tendency to make a showplace out of it. The hordes of the City herded in that direction.

The Spacers put a stop to that. Politely (they were always polite), but without any compromise with tact, they put up a force barrier between themselves and the City. They established a combination Immigration Service and Customs Inspection. If you had business, you identified yourself, allowed yourself to be searched, and submitted to a medical examination and a routine disinfection.

It gave rise to dissatisfaction. Naturally. More dissatisfaction than it deserved. Enough dissatisfaction to put a serious spoke in the program of modernization. Baley remembered the Barrier Riots. He had been part of the mob that had suspended itself from the rails of the expressways, crowded onto the seats in disregard of rating privileges, run recklessly along and across the strips at the risk of a broken body, and remained just outside the Spacetown barrier for two days, shouting slogans and destroying City property out of sheer frustration.

Baley could still sing the chants of the time if he put his mind to it. There was "Man Was Born on Mother Earth, Do You Hear?" to an old folk tune with the gibberish refrain, "Hinky-dinky-parley-voo."

"Man was born on Mother Earth, do you hear?

Earth's the world that gave him birth, do you hear?

Spacer, get you off the face

Of Mother Earth and into space.

Dirty Spacer, do you hear?"

There were hundreds of verses. A few were witty, most were stupid, many were obscene. Every one, however, ended with "Dirty Spacer, do you hear?" Dirty, dirty. It was the futile throwing back in the face of the Spacers their most keenly felt insult: their insistence on considering the natives of Earth as disgustingly diseased.

The Spacers didn't leave, of course. It wasn't even necessary for them to bring any of their offensive weapons into play. Earth's outmoded fleet had long since learned that it was suicide to venture near any Outer World ship. Earth planes that had ventured over the Spacetown area in the very early days of its establishment had simply disappeared. At the most, a shredded wing tip might tumble down to Earth.

And no mob could be so maddened as to forget the effect of the subetheric hand disruptors used on Earthmen in the wars of a century ago.

So the Spacers sat behind their barrier, which itself was the product of their own advanced science, and that no method existed on Earth of breaking. They just waited stolidly on the other side of the barrier until the City quieted the mob with somno vapor and retch gas. The below-level penitentiaries rattled afterward with ringleaders, malcontents, and people who had been picked up simply because they were nearest at hand. After a while they were all set free.

After a proper interval, the Spacers eased their restrictions. The barrier was removed and the City Police entrusted with the protection of Spacetown's isolation. Most important of all, the medical examination was more unobtrusive.

Now, thought Baley, things might take a reverse trend. If the Spacers seriously thought that an Earthman had entered Spacetown and committed murder, the barrier might go up again. It would be bad. He lifted himself onto the expressway platform, made his way through the standees to the tight spiral ramp that led to the upper level, and there sat down. He didn't put his rating ticket in his hatband till they passed the last of the Hudson Sections. A C-5 had no seat rights east of the Hudson and west of Long Island, and although there was ample seating available at the moment, one of the way guards would have automatically ousted him. People were increasingly petty about rating privileges and, in all honesty, Baley lumped himself in with "people."

The air made the characteristic whistling noise as it frictioned off the curved windshields set up above the back of every seat. It made talking a chore, but it was no bar to thinking when you were used to it.

Most Earthmen were Medievalists in one way or another. It was an easy thing to be when it meant looking back to a time when Earth was the world and not just one of fifty. The misfit one of fifty at that. Baley's head snapped to the right at the sound of a female shriek. A woman had dropped her handbag; he saw it for an instant, a pastel pink blob against the dull gray of the strips. A passenger hurrying from the expressway must inadvertently have kicked it in the direction of deceleration and now the owner was whirling away from her property.

A corner of Baley's mouth quirked. She might catch up with it, if she were clever enough to hurry to a strip that moved slower still and if other feet did not kick it this way or that. He would never know whether she would or not. The scene was half a mile to the rear, already.

Chances were she wouldn't. It had been calculated that, on the average, something was dropped on the strips every three minutes somewhere in the City and not recovered. The Lost and Found Department was a huge proposition. It was just one more complication of modern life.

Baley thought: It was simpler once. Everything was simpler. That's what makes Medievalists.

Medievalism took different forms. To the unimaginative Julius Enderby, it meant the adoption of archaisms. Spectacles! Windows!

To Baley, it was a study of history. Particularly the history of folkways.

The City now! New York City in which he lived and had his being. Larger than any City but Los Angeles. More populous than any but Shanghai. It was only three centuries old.

To be sure, something had existed in the same geographic area before then that had been called New York City. That primitive gathering of population had existed for three thousand years, not three hundred, but it hadn't been a City.

There were no Cities then. There were just huddles of dwelling places large and small, open to the air. They were something like the Spacer's Domes, only much different, of course. These huddles (the largest barely reached ten million in population and most never reached one million) were scattered all over Earth by the thousands. By modern standards, they had been completely inefficient, economically. Efficiency had been forced on Earth with increasing population. Two billion people, three billion, even five billion could be supported by the planet by progressive lowering of the standard of living. When the population reaches eight billion, however, semi-starvation becomes too much like the real thing. A radical change had to take place in man's culture, particularly when it turned out that the Outer Worlds (which had merely been Earth's colonies a thousand years before) were tremendously serious in their immigration restrictions.

The radical change had been the gradual formation of the Cities over a thousand years of Earth's history. Efficiency implied bigness. Even in Medieval times that had been realized, perhaps unconsciously. Home industry gave way to factories and factories to continental industries.

Think of the inefficiency of a hundred thousand houses for a hundred thousand families as compared with a hundred-thousand-unit Section; a book-film collection in each house as compared with a Section film concentrate; independent video for each family as compared with video-piping systems.

For that matter, take the simple folly of endless duplication of kitchens and bathrooms as compared with the thoroughly efficient diners and shower rooms made possible by City culture.

More and more the villages, towns, and "cities" of Earth died and were swallowed by the Cities. Even the early prospects of atomic war only slowed the trend. With the invention of the force shield, the trend became a headlong race.

City culture meant optimum distribution of food, increasing utilization of yeasts and hydroponics. New York City spread over two thousand square miles and at the last census its population was well over twenty million. There were some eight hundred Cities on Earth, average population, ten million.

Each City became a semiautonomous unit, economically all but self-sufficient. It could roof itself in, gird itself about, burrow itself under. It became a steel cave, a tremendous, self-contained cave of steel and concrete.

It could lay itself out scientifically. At the center was the enormous complex of administrative offices. In careful orientation to one another and to the whole were the large residential Sections connected and interlaced by the expressway and the localways. Toward the outskirts were the factories, the hydroponic plants, the yeast-culture vats, the power plants. Through all the melee were the water pipes and sewage ducts, schools, prisons and shops, power lines and communication beams.

There was no doubt about it: the City was the culmination of man's mastery over the environment. Not space travel, not the fifty colonized worlds that were now so haughtily independent, but the City.

Practically none of Earth's population lived outside the Cities. Outside was the wilderness, the open sky that few men could face with anything like equanimity. To be sure, the open space was necessary. It held the water that men must have, the coal and the wood that were the ultimate raw materials for plastics and for the eternally growing yeast. (Petroleum had long since gone, but oil-rich strains of yeast were an adequate substitute.) The land between the Cities still held the mines, and was still used to a larger extent than most men realized for growing food and grazing stock. It was inefficient, but beef, pork, and grain always found a luxury market and could be used for export purposes.

But few humans were required to run the mines and ranches, to exploit the farms and pipe the water, and these supervised at long distance. Robots did the work better and required less.

Robots! That was the one huge irony. It was on Earth that the positronic brain was invented and on Earth that robots had first been put to productive use.

Not on the Outer Worlds. Of course, the Outer Worlds always acted as though robots had been born of their culture.

In a way, of course, the culmination of robot economy had taken place on the Outer Worlds. Here on Earth, robots had always been restricted to the mines and farmlands. Only in the last quarter century, under the urgings of the Spacers, had robots filtered their slow way into the Cities.

The Cities were good. Everyone but the Medievalists knew that there was no substitute, no reasonable substitute. The only trouble was that they wouldn't stay good. Earth's population was still rising. Some day, with all that the Cities could do, the available calories per person would simply fall below basic subsistence level.

It was all the worse because of the existence of the Spacers, the descendants of the early emigrants from Earth, living in luxury on their under-populated robot-ridden worlds out in space. They were coolly determined to keep the comfort that grew out of the emptiness of their worlds and for that purpose they kept their birth rate down and immigrants from teeming Earth out. And this -

Spacetown coming up!

A nudge at Baley's unconscious warned him that he was approaching the Newark Section. If he stayed where he was much longer, he'd find himself speeding southwestward to the Trenton Section turning of the way, through the heart of the warm and musty-odored yeast country.

It was a matter of timing. It took so long to shinny down the ramp, so long to squirm through the grunting standees, so long to slip along the railing and out an opening, so long to hop across the decelerating strips.

When he was done, he was precisely at the off-shooting of the proper stationary. At no time did he time his steps consciously. If he had, he would probably have missed.

Baley found himself in unusual semi-isolation. Only a policeman was with him inside the stationary and, except for the whirring of the expressway, there was an almost uncomfortable silence.

The policeman approached, and Baley flashed his badge impatiently. The policeman lifted his hand in permission to pass on.

The passage narrowed and curved sharply three or four times. That was obviously purposeful. Mobs of Earthmen couldn't gather in it with any degree of comfort and direct charges were impossible.

Baley was thankful that the arrangements were for him to meet his partner this side of Spacetown. He didn't like the thought of a medical examination any better for its reputed politeness.

A Spacer was standing at the point where a series of doors marked the openings to the open air and the domes of Spacetown. He was dressed in the Earth fashion, trousers tight at the waist, loose at the ankle, and color-striped down the seam of each leg. He wore an ordinary Textron shirt, open collar, seam-zipped, and ruffled at the wrist, but he was a Spacer. There was something about the way he stood, the way he held his head, the calm and unemotional lines of his broad, high-cheekboned face, the careful set of his short, bronze hair lying flatly backward and without a part, that marked him off from the native Earthman.

Baley approached woodenly and said in a monotone, "I am Plain-clothes Man Elijah Baley, Police Department, City of New York, Rating C-5."

He showed his credentials and went on, "I have been instructed to meet R. Daneel Olivaw at Spacetown Approachway." He looked at his watch. "I am a little early. May I request the announcement of my presence?"

He felt more than a little cold inside. He was used, after a fashion, to the Earth-model robots. The Spacer models would be different. He had never met one, but there was nothing more common on Earth than the horrid whispered stories about the tremendous and formidable robots that worked in superhuman fashion on the far-off, glittering Outer Worlds. He found himself gritting his teeth.

The Spacer, who had listened politely, said, "It will not be necessary. I have been waiting for you."

Baley's hand went up automatically, then dropped. So did his long chin, looking longer in the process. He didn't quite manage to say anything. The words froze.

The Spacer said, "I shall introduce myself. I am R. Daneel Olivaw."

"Yes? Am I making a mistake? I thought the first initial - "

"Quite so. I am a robot. Were you not told?"

"I was told." Baley put a damp hand to his hair and smoothed it back unnecessarily. Then he held it out. "I'm sorry, Mr. Olivaw. I don't know what I was thinking of. Good day. I am Elijah Baley, your partner."

"Good." The robot's hand closed on his with a smoothly increasing pressure that reached a comfortably friendly peak, then declined. "Yet I seem to detect disturbance. May I ask that you be frank with me? It is best to have as many relevant facts as possible in a relationship such as ours. And it is customary on my world for partners to call one another by the familiar name. I trust that that is not counter to your own customs."

"It's just, you see, that you don't look like a robot," said Baley, desperately.

"And that disturbs you?"

"It shouldn't, I suppose, Da - Daneel. Are they all like you on your world?"

"There are individual differences, Elijah, as with men."

"Our own robots... Well, you can tell they're robots, you understand. You look like a Spacer."

"Oh, I see. You expected a rather crude model and were surprised. Yet it is only logical that our people use a robot of pronounced humanoid characteristics in this case if we expected to avoid unpleasantness. Is that not so?"

It was certainly so. An obvious robot roaming the City would be in quick trouble.

Baley said, "Yes."

"Then let us leave now, Elijah."

They made their way back to the expressway. R. Daneel caught the purpose of the accelerating strips and maneuvered along them with a quick proficiency. Baley, who had begun by moderating his speed, ended by hastening it in annoyance.

The robot kept pace. He showed no awareness of any difficulty. Baley wondered if R. Daneel were not deliberately moving slower than he might. He reached the endless cars of expressway and scrambled aboard with what amounted to outright recklessness. The robot followed easily.

Baley was red. He swallowed twice and said, "I'll stay down here with you."

"Down here?" The robot, apparently oblivious to both the noise and the rhythmic swaying of the platform said, "Is my information wrong? I was told that a rating of C-5 entitled one to a seat on the upper level under certain conditions."

"You're right. I can go up there, but you can't."

"Why can I not go up with you?"

"It takes a C-5, Daneel."

"I am aware of that."

"You're not a C-5." Talking was difficult. The hiss of frictioning air was louder on the less shielded lower level and Baley was understandably anxious to keep his voice low.

R. Daneel said, "Why should I not be a C-5? I am your partner and, consequently, of equal rank. I was given this."

From an inner shirt pocket he produced a rectangular credential card, quite genuine. The name given was Daneel Olivaw, without the all-important initial. The rating was C-5.

"Come on up," said Baley, woodenly.

Baley looked straight ahead, once seated, angry with himself, very conscious of the robot sitting next to him. He had been caught twice. First he had not recognized R. Daneel as a robot; secondly, he had not guessed the logic that demanded R. Daneel be given C-5 rating.

The trouble was, of course, that he was not the plain-clothes man of popular myth. He was not incapable of surprise, imperturbable of appearance, infinite of adaptability, and lightning of mental grasp. He had never supposed he was, but he had never regretted the lack before.

What made him regret it was that, to all appearances, R. Daneel Olivaw was that very myth, embodied.

He had to be. He was a robot.

Baley began to find excuses for himself. He was accustomed to the robots like R. Sammy at the office. He had expected a creature with a skin of a hard and glossy plastic, nearly dead white in color. He had expected an expression fixed at an unreal level of inane good humor. He had expected jerky, faintly uncertain motions.

R. Daneel was none of it.

Baley risked a quick side glance at the robot. R. Daneel turned simultaneously to meet his eye and nod gravely. His lips had moved naturally when he had spoken and did not simply remain parted as those of Earth robots did. There had been glimpses of an articulating tongue.

Baley thought: Why does he have to sit there so calmly? This must be something completely new to him. Noise, lights, crowds!

Baley got up, brushed past R. Daneel, and said, "Follow me!"

Off the expressway, down the decelerating strips.

Baley thought: Good Lord, what do I tell Jessie, anyway?

The coming of the robot had rattled that thought out of his head, but it was coming back with sickening urgency now that they were heading down the localway that led into the very jaws of the Lower Bronx Section.

He said, "This is all one building, you know, Daneel; everything you see, the whole City. Twenty million people live in it. The expressways go continuously, night and day, at sixty miles an hour. There are two hundred and fifty miles of it altogether and hundreds of miles of localways."

Any minute now, Baley thought, I'll be figuring out how many tons of yeast product New York eats per day and how many cubic feet of water we drink and how many megawatts of power the atomic piles deliver per hour.

Daneel said, "I was informed of this and other similar data in my briefing."

Baley thought: Well, that covers the food, drink, and power situation, too, I suppose. Why try to impress a robot?

They were at East 182nd Street and in not more than two hundred yards they would be at the elevator banks that fed those steel and concrete layers of apartments that included his own.

He was on the point of saying, "This way," when he was stopped by a knot of people gathering outside the brilliantly lighted force door of one of the many retail departments that lined the ground levels solidly in this Section.

He asked of the nearest person in an automatic tone of authority, "What's going on?"

The man he addressed, who was standing on tiptoe, said, "Damned if I know. I just got here."

Someone else said, excitedly, "They got those lousy R's in there. I think maybe they'll throw them out here. Boy, I'd like to take them apart."

Baley looked nervously at Daneel, but, if the latter caught the significance of the words or even heard them, he did not show it by any outward sign.

Baley plunged into the crowd. "Let me through. Let me through. Police!"

They made way. Baley caught words behind him.

"... take them apart. Nut by nut. Split them down the seams slowlike..." And someone else laughed.

Baley turned a little cold. The City was the acme of efficiency, but it made demands of its inhabitants. It asked them to live in a tight routine and order their lives under a strict and scientific control. Occasionally, built-up inhibitions exploded.

He remembered the Barrier Riots.

Reasons for anti-robot rioting certainly existed. Men who found themselves faced with the prospect of the desperate minimum involved in declassification, after half a lifetime of effort, could not decide cold-bloodedly that individual robots were not to blame. Individual robots could at least be struck at.

One could not strike at something called "governmental policy" or at a slogan like "Higher production with robot labor."

The government called it growing pains. It shook its collective head sorrowfully and assured everyone that after a necessary period of adjustment, a new and better life would exist for all.

But the Medievalist movement expanded along with the declassification process. Men grew desperate and the border between bitter frustration and wild destruction is sometimes easily crossed.

At this moment, minutes could be separating the pent-up hostility of the crowd from a flashing orgy of blood and smash.

Baley writhed his way desperately to the force door.