"And the learning circuits?" "You have to have those," Macintyre said patiently, as though explaining the whole thing to a ten-year-old. "The purpose of the watchbird is to frustrate all murder-attempts, right? Well, only certain murderers give out these stimuli. In order to stop all of them, the watchbird has to search out new definitions of murder and correlate them with what it already knows." "I think it's inhuman," Gelsen said. "That's the best thing about it. The watchbirds are unemotional. Their reasoning is non-anthropomorphic. You can't bribe them or drug them. You shouldn't fear them, either." The intercom on Gelsen's desk buzzed. He ignored it. "I know all this," Gelsen said. "But, still, sometimes I feel like the man who invented dynamite. He thought it would only be used for blowing up tree stumps." "_You_ didn't invent watchbird." "I still feel morally responsible because I manufacture them." The intercom buzzed again, and Gelsen irritably punched a button. "The reports are in on the first week of watchbird operation," his secretary told him. "How do they look?" "Wonderful, sir." "Send them in in fifteen minutes." Gelsen switched the intercom off and turned back to Macintyre, who was cleaning his fingernails with a wooden match. "Don't you think that this represents a trend in human thinking? The mechanical god? The electronic father?" "Chief," Macintyre said, "I think you should study watchbird more closely. Do you know what's built into the circuits?" "Only generally." "First, there is a purpose. Which is to stop living organisms from committing murder. Two, murder may be defined as an act of violence, consisting of breaking, mangling, maltreating or otherwise stopping the functions of a living organism by a living organism. Three, most murderers are detectable by certain chemical and electrical changes." Macintyre paused to light another cigarette. "Those conditions take care of the routine functions. Then, for the learning circuits, there are two more conditions. Four, there are some living organisms who commit murder without the signs mentioned in three. Five, these can be detected by data applicable to condition two." "I see," Gelsen said. "You realize how foolproof it is?" "I suppose so." Gelsen hesitated a moment. "I guess that's all." "Right," the engineer said, and left. Gelsen thought for a few moments. There _couldn't_ be anything wrong with the watchbirds. "Send in the reports," he said into the intercom. * * * * * High above the lighted buildings of the city, the watchbird soared. It was dark, but in the distance the watchbird could see another, and another beyond that. For this was a large city. To prevent murder ... There was more to watch for now. New information had crossed the invisible network that connected all watchbirds. New data, new ways of detecting the violence of murder.