There was graph paper in the drawer of Tick-Tick’s workbench, and a fountain pen. I wrote the date at the top of the page and paused over it, thinking about what Rico had told me about time, and wondering what the real date was. No, local time was as real as anybody ever got. I could settle for Bordertown consensus reality.

I stopped again over the salutation. “Rico,” by itself, was curt and hostile. “Sunny” was too friendly—I didn’t think I’d ever called her that to her face, so why start on paper? “Ms. Rico” made it sound as if I put her in the same category as my high school geography teacher. “Detective Rico” would do—but as soon as I started to write it, it seemed too cold. And should I put “Dear” in front of it? It seemed wildly foolhardy to think of using the word to Sunny Rico.

By this time the ink had dried on the point of the pen, and I had to lick it to make it write again. This was damned silly. It was a note, not the soliloquies from Hamlet. It only had to be short and businesslike. I tore the sheet in half, threw away the part I’d muddled over, and wrote on the rest:

I can’t help—Tick-Tick’s sick, and I have to take care of her. Hope you find out what you need to know.

Now that I’d written it, it looked thin and withdrawn and kind of mean-spirited. In my head, it had sounded brisk and professional. I wanted, suddenly, to commit to paper all the things I’d been chewing over that morning while I should have been sleeping, to see if they struck any answering chord in her. If I did that, though, the possibility of leaving the note at Chrystoble Street would be right out. I compromised:

Did I tell you that Tick-Tick thinks the stuff almost sort of works?

That, now that it was on paper, looked downright cryptic. Well, if she wanted to know more, she could stop by. As soon as that occurred to me, it seemed like a very good idea, and I was suddenly pleased with the unintelligibility of the sentence. I signed my name. Then I thought of something else. I considered starting the letter over on a new sheet, but graph paper was expensive, and since the note was already pretty addled-sounding (I’d veered from being pleased with it to despairing over it in mere seconds), I’d settle for:

P. S. Ask Ms. Wu to have a look at Linn.

After all, if Ms. Wu was tracking epidemics, she ought to be able to authenticate as many cases as possible. And something about this illness had bothered Rico, and nagged at me. Maybe something would come of the exchange of information.