Baley replaced his blaster, but kept his hand unobtrusively upon its butt.

He said, "Walk ahead of us, Clousarr, to Seventeenth Street Exit B."

Clousarr said, "I haven't eaten."

"Tough," said Baley, impatiently. "There's your meal on the floor where you dumped it."

"I have a right to eat."

"You'll eat in detention, or you'll miss a meal. You won't starve. Get going."

All three were silent as they threaded the maze of New York Yeast, Clousarr moving stonily in advance, Baley right behind him, and R. Daneel in the rear.

It was after Baley and R. Daneel had checked out at the receptionist's desk, after Clousarr had drawn a leave of absence and requested that a man be sent in to clean up the balance room, after they were out in the open just to one side of the parked squad car, that Clousarr said, "Just a minute."

He hung back, turned toward R. Daneel, and, before Baley could make a move to stop him, stepped forward and swung his open hand full against the robot's cheek.

"What the devil," cried Baley, snatching violently at Clousarr.

Clousarr did not resist the plain-clothes man's grasp. "It's all right. I'll go. I just wanted to see for myself." He was grinning.

R. Daneel, having faded with the slap, but not having escaped it entirely, gazed quietly at Clousarr. There was no reddening of his cheek, no mark of any blow.

He said, "That was a dangerous action, Francis. Had I not moved backward, you might easily have damaged your hand. As it is, I regret that I must have caused you pain."

Clousarr laughed.

Baley said, "Get in, Clousarr. You, too, Daneel. Right in the back seat with him. And make sure he doesn't move. I don't care if it means breaking his arm. That's an order."

"What about the First Law?" mocked Clousarr.

"I think Daneel is strong enough and fast enough to stop you without hurting you, but it might do you good to have an arm or two broken at that."

Baley got behind the wheel and the squad car gathered speed. The empty wind ruffled his hair and Clousarr's, but R. Daneel's remained smoothly in place.

R. Daneel said quietly to Clousarr, "Do you fear robots for the sake of your job, Mr. Clousarr?"

Baley could not turn to see Clousarr's expression, but he was certain it would be a hard and rigid mirror of detestation, that he would be sitting stiffly apart, as far as he might, from R. Daneel.

Clousarr's voice said, "And my kids' jobs. And everyone's kids."

"Surely adjustments are possible," said the robot. "If your children, for instance, were to accept training for emigration - "

Clousarr broke in. "You, too? The policeman talked about emigration. He's got good robot training. Maybe he is a robot."

Baley growled, "That's enough, you!"

R. Daneel said, evenly, "A training school for emigrants would involve security, guaranteed classification, an assured career. If you are concerned over your children, that is something to consider."

"I wouldn't take anything from a robot, or a Spacer, or any of your trained hyenas in the Government."

That was all. The silence of the motorway engulfed them and there was only the soft whirr of the squad-car motor and the hiss of its wheels on the pavement.

Back at the Department, Baley signed a detention certificate for Clousarr and left him in appropriate hands. Following that, he and R. Daneel took the motospiral up the levels to Headquarters.

R. Daneel showed no surprise that they had not taken the elevators, nor did Baley expect him to. He was becoming used to the robot's queer mixture of ability and submissiveness and tended to leave him out of his calculations. The elevator was the logical method of heaping the vertical gap between Detention and Headquarters. The long moving stairway that was the motospiral was useful only for short climbs or drops of two or three levels at most. People of all sorts and varieties of administrative occupation stepped on and then off in less than a minute. Only Baley and R. Daneel remained on continuously, moving upward in a slow and stolid measure.

Baley felt that he needed the time. It was only minutes at best, but up in Headquarters he would be thrown violently into another phase of the problem and he wanted a rest. He wanted time to think and orient himself. Slowly as it moved, the motospiral went too quickly to satisfy him.

R. Daneel said, "It seems then we will not be questioning Clousarr just yet."

"He'll keep," said Baley, irritably. "Let's find out what the R. Sammy thing is all about." He added in a mutter, far more to himself than to R. Daneel, "It can't be independent; there must be a connection."

R. Daneel said, "It is a pity. Clousarr's cerebric qualities - "

"What about them?"

"They have changed in a strange way. What was it that took place between the two of you in the balance room while I was not present?"

Baley said, absently, "The only thing I did was to preach at him. I passed along the gospel according to St. Fastolfe."

"I do not understand you, Elijah."

Baley sighed and said, "Look, I tried to explain that Earth might as well make use of robots and get its population surplus onto other planets. I tried to knock some of the Medievalist hogwash out of his head. God knows why. I've never thought of myself as the missionary type. Anyway, that's all that happened."

"I see. Well, that makes some sense. Perhaps that can be fitted in. Tell me, Elijah, what did you tell him about robots?"

"You really want to know? I told him robots were simply machines. That was the gospel according to St. Gerrigel. There are any number of gospels, I think."

"Did you by any chance tell him that one could strike a robot without fear of a return blow, much as one could strike any other mechanical object?"

"Except a punching bag, I suppose. Yes. But what made you guess that?" Baley looked curiously at the robot.

"It fits the cerebric changes," said R. Daneel, "and it explains his blow to my face just after we left the factory. He must have been thinking of what you said, so he simultaneously tested your statement, worked off his aggressive feelings, and had the pleasure of seeing me placed in what seemed to him a position of inferiority. In order to be so motivated and allowing for the delta variations in his quintic..."

He paused a long moment and said, "Yes, it is quite interesting, and now I believe I can form a self-consistent whole of the data."

Headquarters level was approaching. Baley said, "What time is it?" He thought, pettishly: Nuts, I could look at my watch and take less time that way.

But he knew why he asked him, nevertheless. The motive was not so different from Clousarr's in punching R. Daneel. To give the robot a trivial order that he must fulfill emphasized his roboticity and, contrariwise, Baley's humanity.

Baley thought: We're all brothers. Under the skin, over it, everywhere. Jehoshaphat!

R. Daneel said, "Twenty-ten."

They stepped off the motospiral and for a few seconds Baley had the usual queen sensation that went with the necessary adjustment to non-motion after long minutes of steady movement.

He said, "And I haven't eaten. Damn this job, anyway."

Baley saw and heard Commissioner Enderby through the open door of his office. The common room was empty, as though it had been wiped clean, and Enderby's voice rang through it with unusual hollowness. His round face looked bare and weak without its glasses, which he held in his hand, while he mopped his smooth forehead with a flimsy paper napkin.

His eyes caught Baley just as the latter reached the door and his voice rose into a petulant tenor.

"Good God, Baley, where the devil were you?"

Baley shrugged off the remark and said, "What's doing? Where's the night shift?" and then caught sight of the second person in the office with the Commissioner.

He said, blankly, "Dr. Gerrigel!"

The gray-haired roboticist returned the involuntary greeting by nodding briefly. "I'm glad to see you again, Mr. Baley."

The Commissioner readjusted his glasses and stared at Baley through them. "The entire staff is being questioned downstairs. Signing statements. I was going mad trying to find you. It looked queer, your being away."

"My being away!" cried Baley, strenuously.

"Anybody's being away. Someone in the Department did it and there's going to be hell to pay for that. What an unholy mess! What an unholy, rotten mess!"

He raised his hands as though in expostulation to heaven and as he did so, his eyes fell on R. Daneel.

Baley thought sardonically: First time you've looked Daneel in the face. Take a good look, Julius!

The Commissioner said in a subdued voice, "He'll have to sign a statement. Even I've had to do it. I!"

Baley said, "Look, Commissioner, what makes you so sure that R. Sammy didn't blow a gasket all by himself? What makes it deliberate destruction?"

The Commissioner sat down heavily. "Ask him," he said, and pointed to Dr. Gerrigel.

Dr. Gerrigel cleared his throat. "I scarcely know how to go about this, Mr. Baley. I take it from your expression that you are surprised to see me."

"Moderately," admitted Baley.

"Well, I was in no real hurry to return to Washington and my visits to New York are few enough to make me wish to linger. And what's more important, I had a growing feeling that it would be criminal for me to leave the City without having made at least one more effort to be allowed to analyze your fascinating robot, whom, by the way," (he looked very eager) "I see you have with you."

Baley stirred restlessly. "That's quite impossible."

The roboticist looked disappointed. "Now, yes. Perhaps later?"

Baley's long face remained woodenly unresponsive.

Dr. Gerrigel went on. "I called you, but you weren't in and no one knew where you could be located. I asked for the Commissioner and he asked me to come to headquarters and wait for you."

The Commissioner interposed quickly. "I thought it might be important. I knew you wanted to see the man."

Baley nodded. "Thanks."

Dr. Gerrigel said, "Unfortunately my guide rod was somewhat off, or perhaps in my over-anxiety I misjudged its temperature. In either case I took a wrong turning and found myself in a small room - "

The Commissioner interrupted again. "One of the photographic supply rooms, Lije."

"Yes," said Dr. Gerrigel. "And in it was the prone figure of what was obviously a robot. It was quite clear to me after a brief examination that he was irreversibly deactivated. Dead, you might say. Nor was it very difficult to determine the cause of the deactivation."

"What was it?" asked Baley.

"In the robot's partly clenched right fist," said Dr. Gerrigel, "was a shiny ovoid about two inches long and half an inch wide with a mica window at one end. The fist was in contact with his skull as though the robot's last act had been to touch his head. The thing he was holding was an alpha-sprayer. You know what they are, I suppose?"

Baley nodded. He needed neither dictionary nor handbook to be told what an alpha-sprayer was. He had handled several in his lab courses in physics: a head-alloy casing with a narrow pit dug into it longitudinally, at the bottom of which was a fragment of a plutonium salt. The pit was capped with a shiver of mica, which was transparent to alpha particles. In that one direction, hard radiation sprayed out.

An alpha-sprayer had many uses, but killing robots was not one of them, not a legal one, at least.

Baley said, "He held it to his head mica first, I take it."

Dr. Gerrigel said, "Yes, and his positronic brain paths were immediately randomized. Instant death, so to speak."

Baley turned to the pale Commissioner. "No mistake? It really was an alpha-sprayer?"

The Commissioner nodded, his plump lips thrust out. "Absolutely. The counters could spot it ten feet away. Photographic film in the storeroom was fogged. Cut and dried."

He seemed to brood about it for a moment or two, then said abruptly, "Dr. Gerrigel, I'm afraid you'll have to stay in the City a day or two until we can get your evidence down on the film. I'll have you escorted to a room. You don't mind being under guard, I hope?"

Dr. Gerrigel said nervously, "Do you think it's necessary?"

"It's safer."

Dr. Gerrigel, seeming quite abstracted, shook hands all around, even with R. Daneel, and left.

The Commissioner heaved a sigh. "It's one of us, Lije. That's what bothers me. No outsider would come into the Department just to knock off a robot. Plenty of them outside where it's safer. And it had to be somebody who could pick up an alpha-sprayer. They're hard to get hold of."

R. Daneel spoke, his cool, even voice cutting through the agitated words of the Commissioner. He said, "But what is the motive for this murder?"

The Commissioner glanced at R. Daneel with obvious distaste, then looked away. "We're human, too. I suppose policemen can't get to like robots any more than anyone else can. He's gone now and maybe it's a relief to somebody. He used to annoy you considerably, Lije, remember?"

"That is scarcely murder motive," said R Daneel.

"No," agreed Baley, with decision.

"It isn't murder," said the Commissioner. "It's property damage. Let's keep our legal terms straight. It's just that it was done inside the Department. Anywhere else it would be nothing. Nothing. Now it could be a first-class scandal. Lije!"

"Yes?"

"When did you last see R. Sammy?"

Baley said, "R. Daneel spoke to R. Sammy after lunch. I should judge it was about 13:30. He arranged to have us use your office, Commissioner."

"My office? What for?"

"I wanted to talk over the case with R. Daneel in moderate privacy. You weren't in, so your office was an obvious place."

"I see." The Commissioner looked dubious, but let the matter ride. "You didn't see him yourself?"

"No, but I heard his voice perhaps an hour afterward."

"Are you sure it was he?"

"Perfectly."

"That would be about 14:30?"

"Or a little sooner."

The Commissioner bit his pudgy lower lip thoughtfully. "Well, that settles one thing."

"It does?"

"Yes. The boy, Vincent Barrett, was here today. Did you know that?"

"Yes. But, Commissioner, he wouldn't do anything like this."

The Commissioner lifted his eyes to Baley's face. "Why not? R. Sammy took his job away. I can understand how he feels. There would be a tremendous sense of injustice. He would want a certain revenge. Wouldn't you? But the fact is that he left the building at 14:00 and you heard R. Sammy alive at 14:30. Of course, he might have given the alpha-sprayer to R. Sammy before he left with instructions not to use it for an hour, but then where could he have gotten an alpha-sprayer? It doesn't bear thinking of. Let's get back to R. Sammy. When you spoke to him at 14:30, what did he say?"

Baley hesitated a perceptible moment, then said carefully, "I don't remember. We left shortly afterward."

"Where did you go?"

"Yeast-town, eventually. I want to talk about that, by the way."

"Later. Later." The Commissioner rubbed his chin. "Jessie was in today, I noticed. I mean, we were checking on all visitors today and I just happened to see her name."

"She was here," said Baley, coldly.

"What for?"

"Personal family matters."

"She'll have to be questioned as a pure formality."

"I understand police routine, Commissioner. Incidentally, what about the alpha-sprayer itself? Has it been traced?"

"Oh, yes. It came from one of the power plants."

"How do they account for having lost it?"

"They don't. They have no idea. But look, Lije, except for routine statements, this has nothing to do with you. You stick to your case. It's just that... Well, you stick to the Spacetown investigation."

Baley said, "May I give my routine statements later, Commissioner? The fact is, I haven't eaten yet."

Commissioner Enderby's glassed-eyes turned full on Baley. "By all means get something to eat. But stay inside the Department, will you? Your partner's right, though, Lije" - he seemed to avoid addressing R. Daneel or using his name - "it's the motive we need. The motive."

Baley felt suddenly frozen.

Something outside himself, something completely alien, took up the events of this day and the day before and the day before and juggled them. Once again pieces began to dovetail; a pattern began to form.

He said, "Which power plant did the alpha-sprayer come from, Commissioner?"

"The Williamsburg plant. Why?"

"Nothing. Nothing."

The last word Baley heard the Commissioner mutter as he strode out of the office, with R. Daneel immediately behind him, was, "Motive. Motive."

Baley ate a sparse meal in the small and infrequently used Department lunchroom. He devoured the stuffed tomato on lettuce without being entirely aware of its nature and for a second or so after he had gulped down the last mouthful his fork still slithered aimlessly over the slick cardboard of his plate, searching automatically for something that was no longer there.

He became aware of that and put down his fork with a muffled, "Jehoshaphat!"

He said, "Daneel!"

R. Daneel had been sitting at another table, as though he wished to leave the obviously preoccupied Baley in peace, or as though he required privacy himself. Baley was past caring which.

Daneel stood up, moved to Baley's table, and sat down again. "Yes, partner Elijah?"

Baley did not look at him. "Daneel, I'll need your co-operation."

"In what way?"

"They will question Jessie and myself. That is certain. Let me answer the questions in my own way. Do you understand?"

"I understand what you say, of course. Nevertheless, if I am asked a direct question, how is it possible for me to say anything but what is so?"

"If you are asked a direct question, that's another matter. I ask only that you don't volunteer information. You can do that, can't you?"

"I believe so, Elijah, provided it does not appear that I am hurting a human being by remaining silent."

Baley said, grimly, "You will hurt me if you don't. I assure you of that."

"I do not quite understand your point of view, partner Elijah. Surely the matter of R. Sammy cannot concern you."

"No? It all centers about motive, doesn't it? You've questioned the motive. The Commissioner questioned it. I do, for that matter. Why should anyone want to kill R. Sammy? Mind you, it's not just a question of who would want to smash up robots in general. Any Earthman, practically, would want to do that. The question is, who would want to single out R. Sammy. Vincent Barrett might, but the Commissioner said he couldn't get hold of an alpha-sprayer, and he's right. We have to look somewhere else, and it so happens that one other person has a motive. It glares out. It yells. It stinks to top level."

"Who is the person, Elijah?"

And Baley said, softly, "I am, Daneel."

R. Daneel's expressionless face did not change under the impact of the statement. He merely shook his head.

Baley said, "You don't agree. My wife came to the office today. They know that already. The Commissioner is even curious. If I weren't a personal friend, he wouldn't have stopped his questioning so soon. Now they'll find out why. That's certain. She was part of a conspiracy; a foolish and harmless one, but a conspiracy just the same. And a policeman can't afford to have his wife mixed up with anything like that. It would be to my obvious interest to see that the matter was hushed up.

"Well, who knew about it? You and I, of course, and Jessie - and R. Sammy. He saw her in a state of panic. When he told her that we had left orders not to be disturbed, she must have lost control. You saw the way she was when she first came in."

R. Daneel said, "It is unlikely that she said anything incriminating to him."

"That may be so. But I'm reconstructing the case the way they will. They'll say she did. There's my motive. I killed him to keep him quiet."

"They will not think so."

"They will think so. The murder was arranged deliberately in order to throw suspicion on me. Why use an alpha-sprayer? It's a rather risky way. It's hard to get and it can be traced. I think that those were the very reasons it was used. The murderer even ordered R. Sammy to go into the photographic supply room and kill himself there. It seems obvious to me that the reason for that was to have the method of murder unmistakable. Even if everyone was so infantile as not to recognize the alpha-sprayer immediately, someone would be bound to notice fogged photographic film in fairly short order."

"How does that all relate to you, Elijah?"

Bailey grinned tightly, his long face completely devoid of humor. "Very neatly. The alpha-sprayer was taken from the Williamsburg power plant. You and I passed through the Williamsburg power plant yesterday. We were seen, and the fact will come out. That gives me opportunity to get the weapon as well as motive for the crime. And it may turn out that we were the last ones to see or hear R. Sammy alive, except for the real murderer, of course."

"I was with you in the power plant and I can testify that you did not have the opportunity to steal an alpha-sprayer."

"Thanks," said Baley sadly, "but you're a robot and your testimony will be invalid."

"The Commissioner is your friend. He will listen."

"The Commissioner has a job to keep, and he already is a bit uneasy about me. There's only one chance of saving myself from this very nasty situation."

"Yes?"

"I ask myself, why am I being framed? Obviously to get rid of me. But why? Again obviously, because I am dangerous to someone. I am doing my best to be dangerous to whoever killed Dr. Sarton in Spacetown. That might mean the Medievalists, of course, or at least, the inner group among them. It would be this inner group that would know I had passed through the power plant; at least one of them might have followed me along the strips that far, even though you thought we had lost them.

"So the chances are that if I find the murderer of Dr. Sarton, I find the man or men who are trying to get me out of the way. If I think it through, if I crack the case, if I can only crack it, I'll be safe. And Jessie. I couldn't stand to have her. - But I don't have much time." His fist clenched and unclenched spasmodically. "I don't have much time."

Baley looked at R. Daneel's chiseled face with a sudden burning hope. Whatever the creature was, he was strong and faithful, animated by no selfishness. What more could you ask of any friend? Baley needed a friend and he was in no mood to cavil at the fact that a gear replaced a blood vessel in this particular one.

But R. Daneel was shaking his head.

The robot said, "I am sorry, Elijah" - there was no trace of sorrow on his face, of course - "but I anticipated none of this. Perhaps my action was to your harm. I am sorry if the general good requires that."

"What general good?" stammered Baley.

"I have been in communication with Dr. Fastolfe."

"Jehoshaphat! When?"

"While you were eating."

Baley's lips tightened.

"Well?" he managed to say. "What happened?"

"You will have to clear yourself of suspicion of the murder of R. Sammy through some means other than the investigation of the murder of my designer, Dr. Sarton. Our people at Spacetown, as a result of my information, have decided to bring that investigation to an end, as of today, and to begin plans for leaving Spacetown and Earth."