"In the beginning, that circuit was a formless matrix and only faintly resembled your nervous system. As nerve data was exchanged back and forth, it began to resemble you more and more, especially your mind.

Now, for practical purposes, it is you and I can look into it at will."

Jadiver stirred uneasily.

"Don't you understand?" asked the robot. "My mind isn't yours, and vice versa. But we do have one thing in common, a synthetic nervous system which, if you were killed, would begin to disintegrate slowly and painfully. And now that it's developed as much as it is, I would probably die, too, since that synthetic nervous system is an otherwise unused part of my brain."

"There were two other victims before me," said Jadiver.

"There were, but they were derelicts--dead, really, before the experiment got started. They lasted a few hours. I tried to help them, but it was too late. It was not pleasant for me."

Not only was it a friend; it had a vital interest in keeping him alive.

He could trust it, had to. After what had happened, doubt wasn't called for.

Jadiver rubbed his weary eyes. "That shield I used," he said. "Did it work?"

The robot laughed--Jadiver's laughter. It had copied him in many ways.

"It worked to your disadvantage. The circuit signals got through to me, but I couldn't send any back until Doumya Filone chipped off part of your disguise. Then I spoke to you. Before that, I had to misdirect the police. I built up a complete and false history for you and kept them looking where you weren't."

If he had thought, he would have known it had to be that way. The police were efficient; they could have taken him long ago without the aid of the circuit. But it had seemed so easy and they had trusted the robot--had to where the circuit was concerned. No man could sit in front of a screen and interpret the squiggles that meant his hand was touching an apple.

Jadiver sat down. The strain was over and he was safe, bound for some far-off place.

"The police used you, though not as much as you used them," he said.

"Still, they didn't develop the theory."

"They didn't. There was a man on Earth, a top-notch scientist. He worked out the theory and set up the mechanism. He had a surgical a.s.sistant, a person who would never be more than that on Earth because she wasn't good on theory, though she was a whiz at surgery. She realized it and got his permission to build another machine and take it to Venus.

Originally it was intended to acc.u.mulate data on the workings of the human nervous system.

"On Venus, things were different. Laws concerning the rights of individuals are not so strict. She got the idea of examining the whole nervous system at once, not realizing what it meant because it had never been done that way. She discussed it with officials from the police department who saw instantly what she didn't--that once an extensive circuit was in a human, there was no way to get it out, except by death.

They had no objections and were quite willing to furnish her with specimens, for their own purposes and only incidentally hers. Once the first man died, they had her and wouldn't let her back out, though she wanted to."

"Specimen," repeated Jadiver. "Yeah, I was a specimen to her." His head was heavy. "Why didn't you tell me this in the beginning?"

"Would you have listened when I first contacted you?" asked the robot.

"Later, perhaps. But once you put on the shield, I couldn't get in touch with you until you were with Doumya Filone."

Would Jadiver have listened? Not until it became a matter of raw survival. Even now he hated to leave Earth and what it meant for the unknown dangers and tedium of a planet circling an alien sun. It was more than that, of course. Just as he'd had a design for a perfect robot, he had in mind a perfect woman. He could recognize either when he saw it.

"Doumya Filone was the a.s.sistant?"

"She was." The robot was his now, Jadiver knew. Others had built it, but it belonged to him by virtue of a nervous system. It had as good a mind as his, but it wouldn't dispute his claim. "Like yourself," continued the robot, "in the Solar System she would never have been more than second rate, and she wanted to be first. Hardly anyone recognizes it, but the Solar System is not what it once was. It's like a nice neighborhood that decays so slowly that the people in it don't notice what it's become. There are some who can rise even in a slum, but they're the rare exceptions.

"Others need greater opportunity than slums offer. They have to leave if they expect to develop freely. But the hold of a whole culture is strong and it's hard to persuade them that they have to go." The robot paused.

"Take a last look at a blighted area."

Outside planets glimmered in the distance.

Jadiver was tired and his eyes were closing. Now he could sleep safely, but not in peace.

"Don't regret it," advised the robot. "Where you're going, you'll have real designs to work on. No more pretty robot faces."

"Where is it--Alpha Centauri?" Jadiver asked disinterestedly.

"That ship left yesterday. They got their quota and left within the hour, before any of the pa.s.sengers could change their minds. We're going farther, to Sirius."

Sirius. A mighty sun, with planets to match. It was a place to be big.

Big and lonely.

"I can't force you to do anything," said the robot. It sounded pleased.

"But I have no inhibitions about others."

The robot flipped up its cowl. There was a storage s.p.a.ce and a woman in it.

Except for her hands, she was bound tightly by tangle strands.

"I don't think she likes you at the moment," said the robot. "She'll tell you that as soon as she's able to speak. She may relent later, when she realizes what it's really like on Sirius. You've got the whole voyage to convince her."

The eye-stalks of the robot followed Jadiver interestedly. "Are you looking for the tongs? Remember that the tangle stuff is repelled by your skin."

Jadiver willingly used his hands and the tangle strands fell off.

As the robot had predicted, Doumya Filone was not silent--at first.