I did. She turned to the apothecary’s chest in a parody of the scene I’d imagined, sliding out the little drawers and bringing calico-wrapped parcels or crushed leaves in waxed paper bags or tiny brown glass vials out of them. Her hands trembled a little, and the veins stood out in the backs of them.

“What do you think it is?” I asked.

She pushed all the things she’d taken out of the chest into a tight pile on the counter, and stood staring at them. “I think,” she began, slowly; then she stopped herself. A much-diluted version of her smile flickered on her face. “I think that not even you would be so silly as to ask the doctor for a diagnosis when her patient is halfway across town. How did you get here?”

“On foot.”

“I have a bicycle, so I’m afraid I can’t give you a ride back. Tell me the address, and I’ll meet you there.”

“I could lead you—”

“I’m sure you could, but it would be much slower, really.”

I figured out that what she really wanted was to be relieved of me hanging over her shoulder and worrying while she packed her bag. So I did as I was told, and loped off to Tick-Tick’s again.

We arrived at our destination at pretty much the same time. Ms. Wu did it on a particularly nice all-terrain bike with fifteen speeds, well-suited to the uncertain topography and pavement of Bordertown. She hoisted her black leather bag out of the wire basket over the back wheel and told me, “Lead the way.” I’d remembered, when I’d left to fetch her, to take one of Tick-Tick’s keys to the front door, so I did that.

When we came in, the Ticker was sitting propped up against the raised end of the fainting couch with an Arabian Nights-ish shawl spread over her legs, looking tidy and composed. The cough spoiled the effect a little, and the weakness of her voice when she said, “Gracious, that was quick.” But it galled her to receive company in a state of disarray, and I knew that, however much effort she’d gone to to make it look as if she wasn’t sick, it was necessary to her peace of mind.