I looked at our teacher in amazement. She was a bright old woman, of course, but there was the science section . . .

“It’s my hobby,” Anna Tikhonovna said modestly. “I don’t have the strength to go chasing bloodsuckers through the streets, my health won’t allow it. And I don’t think I’m any kind of genius. But I do have a lot of free time, so I spend it on things that our men of science don’t take into account . . .”

“I have only myself to blame that I didn’t know about this any sooner,” said Gesar. “I expect things would have been a lot simpler with the Tiger.”

“I study Mirrors, Shades, the Transparent Other, Tigers, the Clapper, the Clay Man . . .” Anna Tikhonovna continued.

“The Transparent Other? The Clapper? The Clay Man?” To say I was surprised would have been putting it mildly.

“Oh, Anton, they are such interesting phenomena!” Anna Tikhonovna exclaimed, warming to her subject. “The Clapper, for instance, only appears on the second level of the Twilight. In the whole of history, only five cases have been recorded. When an Other—”

“Anna Tikhonovna, I’m prepared to concede that there is something to this item of folklore too,” said Gesar. “But let’s get back to the Tiger.”

“You ferreted out everything about the Tiger yourself,” the teacher sighed. “It’s a pity, of course, that you didn’t come to me, I could have saved you heaps of time. The only thing I have is—I know Erasmus’s address.”

“Erasmus Darwin?” I exclaimed in delight.

“Anton, don’t even ask me how I got hold of it,” said Anna Tikhonovna, lowering her eyes modestly. “You know that according to the law, no one has the right to disturb an Other who has deliberately withdrawn from active involvement with the Watches . . .”

“I would have needed permission from the head of the local Night Watch and a clear statement from the head of the Day Watch that he didn’t object, simply in order to apply to the local branch of the Inquisition for the address to be released,” said Gesar. “And even then they could easily not have given me it . . .”

“But I went about it more simply,” said Anna Tikhonovna, unable to resist, and started telling her story, despite that “don’t even ask me how I got hold of it” business. “I read Erasmus’s The Loves of the Plants and wrote a critical treatise on it. Well . . . partly laudatory and partly critical. Just critical enough to pique Erasmus slightly. I published it in an English journal—and a week later I received a rejoinder.”

She smiled. I couldn’t help smiling too.

“So our dendrophile took the bait . . . What happened then?”