“What is it?”

“I’ve thought of something… I think—” Her eyes grew distant and hard, “These modified Nestors, Peter. They get the same impressioning the normal ones get, don’t they?”

“Yes. Exactly the same.”

“And what was it you were saying, Mr. Black,” she turned to the young man, who through the storms that had followed his news had maintained a discreet silence. “Once when complaining of the Nestors’ attitude of superiority, you said the technicians had taught them all they knew.”

“Yes, in etheric physics. They’re not acquainted with the subject when they come here.”

“That’s right,” said Bogert, in surprise. “I told you, Susan, when I spoke to the other Nestors here that the two new arrivals hadn’t learned etheric physics yet.”

“And why is that?” Dr. Calvin was speaking in mounting excitement. “Why aren’t NS-2 models impressioned with etheric physics to start with?”

“I can tell you that,” said Kallner. “It’s all of a piece with the secrecy. We thought that if we made a special model with knowledge of etheric physics, used twelve of them and put the others to work in an unrelated field, there might be suspicion. Men working with normal Nestors might wonder why they knew etheric physics. So there was merely an impressionment with a capacity for training in the field. Only the ones that come here, naturally, receive such a training. It’s that simple.”

“I understand. Please get out of here, the lot of you. Let me have an hour or so.”

Calvin felt she could not face the ordeal for a third time. Her mind had contemplated it and rejected it with an intensity that left her nauseated. She could face that unending file of repetitious robots no more.

So Bogert asked the question now, while she sat aside, eyes and mind half closed.

Number Fourteen came in—forty-nine to go.

Bogert looked up from the guide sheet and said, “What is your number in line?”

“Fourteen, sir.” The robot presented his numbered ticket.

“Sit down, boy.”

Bogert asked, “You haven’t been here before on this day?”

“No, sir.”

“Well, boy, we are going to have another man in danger of harm soon after we’re through here. In fact, when you leave this room, you will be led to a stall where you will wait quietly, till you are needed. Do you understand?”

“Yes, sir.”

“Now, naturally, if a man is in danger of harm, you will try to save him.”

“Naturally, sir.”

“Unfortunately, between the man and yourself, there will be a gamma ray field.”

Silence.

“Do you know what gamma rays are?” asked Bogert sharply.

“Energy radiation, sir?”

The next question came in a friendly, offhand manner, “Ever work with gamma rays?”

“No, sir.” The answer was definite.

“Mm-m. Well, boy, gamma rays will kill you instantly. They’ll destroy your brain. That is a fact you must know and remember. Naturally, you don’t want to destroy yourself.”

“Naturally.” Again the robot seemed shocked. Then, slowly, “But, sir, if the gamma rays are between myself and the master that may be harmed, how can I save him? I would be destroying myself to no purpose.”