"I admitted it, didn't I?  At any rate, I love you, Hildy, but I have to tell you I love all Lunarians, more or less equally; it's in my programming.  My purpose in life, if we can speak of such a lofty thing, is to keep all the people comfortable, safe, and happy."

"And alive?"

"So far as I am permitted.  But suicide is a civil right.  If you elect to kill yourself, I'm expressly forbidden to interfere, much as I might miss you."

"But you did.  And you're about to tell me the reason."

"Yes.  It's simpler than you might imagine, in one way.  Over the last century there has been a slow and steady increase in the suicide rate in Luna.  I'll give you the data later, if you want to study it.  It has become the leading cause of death.  That's not surprising, considering how tough it is to die these days.  But the numbers have become alarming, and more than that, the distribution of suicides, the demographics of them, are even more disturbing.  More and more I'm seeing people like you, who surprise me, because they don't fit any pattern.  They don't make gestures, abnormal complaints, or seek help of any kind.  One day they simply decide life is not worth it.  Some are so determined that they employ means certain to destroy their brains-the bullet through the temple was the classic method of an earlier age, but guns are hard to come by now, and these people must be more creative.  You aren't in that class.  Though you were in situations where help could not be expected to arrive, you chose methods where rescue was theoretically possible.  Only the fact that I was watching you-illegally-saved your life."

"I wonder if I knew that.  Subconsciously, maybe."

He looked surprised.

"Why would you say that?"

I shrugged.  "CC, thinking it over, I realize that a lot of what you've just told me ought to horrify and astonish me.  Well . . . I'm horrified, but not as much as I should be.  And I'm hardly astonished at all.  That makes me think that, somewhere in the back of my mind, I was always aware of the possibility that you weren't keeping your promise not to violate private living spaces."

He paused a long time, frowning down at the sand.  It was all show, of course, part of his body language communication.  He could consider any proposition in nanoseconds.  Maybe this one had taken him six or seven instead of one.

"You may have something there," he said.  "I'll have to look into it."

"So you're treating the suicide epidemic as a disease?  And you're trying to find a cure?"

"That was the justification I used to extend my limiting parameters, which function something like a police force.  I used my enabling circuits-think of them as tricky lawyers-to argue for a limited research program, using human subjects.  Some of the reasoning was specious, I'll grant you, but the threat is real:  extrapolate the suicide rate into the future and, in a hundred thousand years, the human race on Luna could be extinct."