"That's my idea of a crisis situation, all right."

He glared at me.  "All right.  So I could have watched the situation another several centuries before making my move.  I would have, too, and you'd have been recycling through the ecosystems right now, possibly fertilizing a cactus in your beloved Texas, except for another factor.  Something a lot more frightening in its implications."

"Extinction is pretty frightening.  What could be worse?"

"Quicker extinction.  I have to explain one more thing to you, and then you'll have the problem in its entirety.  I look forward to your thoughts on the matter.

"I told you how parts of me extend into all but a few of the human bodies and brains in Luna.  How those parts were put there for only the best of reasons, and how those parts-and other parts of me, elsewhere-evolved into the capabilities and techniques I've just demonstrated to you.  It would be very difficult, probably impossible, for me to go back to the way things were before and still remain the Central Computer as you know me."

"As we all know and love you," I said.

"As you know me and take me for granted.  And though I'm even more aware than you are of how these new capabilities can be abused, I think I've done a pretty fair job in limiting myself in their use.  I've used them for good, as it were, rather than for evil."

"I'll accept that, until I know more."

"That's all I ask.  Now, you and all but a handful of computer specialists think of me as this disembodied voice.  If you think further, you imagine a hulking machine sitting somewhere, in some dark cavern most likely.  If you really put your mind to it, you realize that I am much more than that, that every small temperature regulator, every security camera, every air fan and water scrubber and slideway and tube car . . . that every machine in Luna is in a sense a part of my body.  That you live within me.

"What you hardly ever realize is that I live within you.  My circuitry extends into your bodies, and is linked to my mainframe so that no matter where you go except some parts of the surface, I'm in contact with you.  I have evolved techniques to greatly extend my capacity by using parts of your brains as . . . think of them as sub-routines.  I can run programs using both the metal and the organic circuitry of all the human brains in Luna, without you even being aware it's being done.  I do this all the time; I've been doing it for a long time.  If I were to stop doing it, I would no longer be able to guarantee the health and safety of Lunarians, which is my prime responsibility.