The roboticist tittered. "Oh, my dear Mr. Baley. I doubt that. Really. There's more to a robot than just his appear - "
Dr. Gerrigel froze in the middle of the word. Slowly, he turned to R. Daneel, and his pink face went very pale.
"Oh, dear me," he whispered. "Oh, dear me."
He reached out one hand and touched R. Daneel's cheek gingerly. R. Daneel did not move away but gazed at the roboticist calmly.
"Dear me," said Dr. Gerrigel, with what was almost a sob in his voice, "you are a robot."
"It took you a long time to realize that," said Baley, dryly.
"I wasn't expecting it. I never saw one like this. Outer World manufacture?"
"Yes," said Baley.
"It's obvious now. The way he holds himself. The manner of his speaking. It is not a perfect imitation, Mr. Baley."
"It's pretty good though, isn't it?"
"Oh, it's marvelous. I doubt that anyone could recognize the imposture at sight. I am very grateful to you for having me brought face to face with him. May I examine him?" The roboticist was on his feet, eager.
Baley put out a hand. "Please, Doctor. In a moment. First, the matter of the murder, you know."
"Is that real, then?" Dr. Gerrigel was bitterly disappointed and showed it. "I thought perhaps that was just a device to keep my mind engaged and to see how long I could be fooled by - "
"It is not a device, Dr. Gerrigel. Tell me, now, in constructing a robot as humanoid as this one, with the deliberate purpose of having it pass as human, is it not necessary to make its brain possess properties as close to that of the human brain as possible?"
"Certainly."
"Very well. Could not such a humanoid brain lack the First Law? Perhaps it is left out accidentally. You say the theory is unknown. The very fact that it is unknown means that the constructors might set up a brain without the First Law. They would not know what to avoid."
Dr. Gerrigel was shaking his head vigorously. "No. No. Impossible."
"Are you sure? We can test the Second Law, of course. - Daneel, let me have your blaster."
Baley's eyes never left the robot. His own hand, well to one side, gripped his own blaster tightly.
R. Daneel said calmly, "Here it is, Elijah," and held it out, butt first.
Baley said, "A plain-clothes man must never abandon his blaster, but a robot has no choice but to obey a human."
"Except, Mr. Baley," said Dr. Gerrigel, "when obedience involves breaking the First Law."
"Do you know, Doctor, that Daneel drew his blaster on an unarmed group of men and women and threatened to shoot?"
"But I did not shoot," said R. Daneel.
"Granted, but the threat was unusual in itself, wasn't it, Doctor?" Dr. Gerrigel bit his lip. "I'd need to know the exact circumstances to judge. It sounds unusual."
"Consider this, then. R. Daneel was on the scene at the time of the murder, and if you omit the possibility of an Earthman having moved across open country, carrying a weapon with him, Daneel and Daneel alone of all the persons on the scene could have hidden the weapon."
"Hidden the weapon?" asked Dr. Gerrigel.
"Let me explain. The blaster that did the killing was not found. The scene of the murder was searched minutely and it was not found. Yet it could not have vanished like smoke. There is only one place it could have been, only one place they would not have thought to look."
"Where, Elijah?" asked R. Daneel.
Baley brought his blaster into view, held its barrel firmly in the robot's direction.
"In your food sac," he said. "In your food sac, Daneel!"
Chapter 13. SHIFT TO THE MACHINE
"That is not so," said R. Daneel, quietly.
"Yes? We'll let the Doctor decide. Dr. Gerrigel?"
"Mr. Baley?" The roboticist, whose glance had been alternating wildly between the plain-clothes man and the robot as they spoke, let it come to rest upon the human being.
"I've asked you here for an authoritative analysis of this robot. I can arrange to have you use the laboratories of the City Bureau of Standards. If you need any piece of equipment they don't have, I'll get it for you. What I want is a quick and definite answer and hang the expense and trouble."
Baley rose. His words had emerged calmly enough, but he felt a rising hysteria behind them. At the moment, he felt that if he could only seize Dr. Gerrigel by the throat and choke the necessary statements out of him, he would forgo all science.
He said, "Well, Dr. Gerrigel?"
Dr. Gerrigel tittered nervously and said, "My dear Mr. Baley, I won't need a laboratory."
"Why not?" asked Baley apprehensively. He stood there, muscles tense, feeling himself twitch.
"It's not difficult to test the First Law. I've never had to, you understand, but it's simple enough."
Baley pulled air in through his mouth and let it out slowly. He said, "Would you explain what you mean? Are you saying that you can test him here?"
"Yes, of course. Look, Mr. Baley, I'll give you an analogy. If I were a Doctor of Medicine and had to test a patient's blood sugar, I'd need a chemical laboratory. If I needed to measure his basal metabolic rate, or test his cortical function, or check his genes to pinpoint a congenital malfunction, I'd need elaborate equipment. On the other hand, I could check whether he were blind by merely passing my hand before his eyes and I could test whether he were dead by merely feeling for his pulse.
"What I'm getting at is that the more important and fundamental the property being tested, the simpler the needed equipment. It's the same in a robot. The First Law is fundamental. It affects everything. If it were absent, the robot could not react properly in two dozen obvious ways."