into the induction field in the operator's head…I am out of my area now and into that of Weber and Fechner, but a neuron has a threshold at which it will fire, and below which it will not. There are some forty thousand neurons packed together in a square millimeter of the cerebral cortex, in such a fashion that each one has several hundred synaptic connections with others about it. At any given moment, some of them may be way below the firing threshold while others are in a condition Sir John Eccles once referred to as 'critically poised', ready to fire. If just one is pushed over the threshold, it can affect the discharge of hundreds of thousands of others within twenty milliseconds. The pulsating field was to provide such a push in a sufficiently selective fashion to give the operator an idea as to what was going on in the Hangman's brain. And vice versa. The Hangman was to have its own built-in version of the same thing. It was also thought that this might serve to humanize it somewhat, so that it would better appreciate the significance of its work, to instill something like loyalty, you might say."

"Do you think this could have contributed to its later breakdown?"

"Possibly. How can you say in a one-of-a-kind situation like this? If you want a guess, I'd say, 'Yes.' But its just a guess."

"Uh-huh," he said, "and what were its physical capabilities?"

"Anthropomorphic design," I said, "both because it was originally telefactored and because of the psychological reasoning I just mentioned. It could pilot its own small vessel. No need for a life-support system, of course. Both it and the vessel were powered by fusion units, so that fuel was no real problem. Self-repairing. Capable of performing a great variety of sophisticated tests and measurements, of making observations, completing reports, learning new material, broadcasting its findings back here. Capable of surviving just about anywhere. In fact, it