“But that name is not important now,” she went on.

I swallowed, and nodded.

“Listen,” said the guest lecturer, with an air that suggested that the preliminary portion of the conversation was now coming to a close. “I’m here to help you.”

I nodded again.

“But I don’t have very much time. You’re going to have to listen very carefully to what I have to say. Can you do that?”

I had the fleeting thought that this guest lecturer, although physically identical to the one I’d met before, had an entirely different manner.

“Yes,” I said. “Yes, of course.”

“Good,” she said. She adjusted the crease of her linen pants.

“I understand,” she said, “that you are in the midst of an investigation into your father’s death.”

I nodded, temporarily unable to speak. To hear one’s secret projects spoken aloud by someone else—I was deeply moved. But there was no time to think of that now, because the guest lecturer had already begun to speak again.

“That’s good,” she said. “It’s admirable.”

She went on: “It has come to my attention that you attempted to make inquiries at the Old Mission Hotel, concerning whether or not your father had been a guest there.”

She turned to look at me with her eyebrows raised.

“That’s right,” I said hoarsely.

“That was also good,” she said. “You’re on the right track.”

I heard myself whisper faintly, “On the right track?”

“Yes,” said the guest lecturer. “But here’s the thing,” she said, and her voice took on a new, more serious note. “That isn’t the right name.”

“Not the right name?” I repeated. I was having trouble keeping everything straight.

“No,” said the guest lecturer, and now she was the picture of seriousness. “You need to ask about a different name.”

I swallowed.

“Are you saying,” I said, feeling a little feverish, “that my father stayed at the hotel under an alias?”

It had not occurred to me, and yet it was so simple. Of course, when people want to cover their tracks, they use false names.

The guest lecturer gave me a withering look. “Yes,” she said. “That’s exactly what I mean.”

At this juncture in the meeting she lifted her wrist to look at a small silver watch—had she worn it the night we’d met? It did not look familiar—and frowned.

I wanted to tell her to wait, that I didn’t yet understand what she was saying, but before I could do so I was interrupted by the sight of something that struck me as odd.

From her left wrist to her left elbow stretched a long, thin scar—when she’d raised her arm to look at her watch, the sleeve of her jacket had fallen down, exposing it. This was no trick of the light; I could see the seam of tissue clearly, a slightly raised, shiny white scar.