He walked slowly down the stairs and stood beside it.
The robot switched to the regular speaking voice. "They built your design, after all. They needed a big and powerful mobile robot, one that could house, in addition to the regular functions, an extensive and delicate mechanism."
That was the voice that had haunted him so long and in so many situations. It was not Jadiver's own voice, but it resembled his. A third person might not recognize the difference.
"That other mechanism," said Jadiver. "Is that the one that monitors the circuit in my body?"
"That parallels the circuit in your body." Tentacles were busy straightening out the dents. "When I was built, they gave me a good mind, better than your own in certain respects. What I lacked was sensory perception. Eyes and ears, to be sure, good ones in a way, but without the delicate shadings a human has, particularly tactile interpretations. I didn't need better, they thought, because my function was to observe and report on the parallel circuit I mentioned.
"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."