“It all began, I imagine,” said Kevin, “with Dante, when he included in his fictional Divine Comedy portraits of his enemies. I would suppose it’s even an older practice than that.”

“Much older,” offered another of the guests, a hirsute Harvard student. “All the Greek playwrights did it in their comedies. Aristophanes got in a lot of trouble because of it.”

“Not surprising,” Kevin continued, “and we’re all familiar with historical works that are, finally, more fictitious than the most imaginative novel.” Several students chuckled.

Kevin was smoking a briar, sitting on the edge of the table, fingering the open pages of one of the reference works. “But consider this angle. Suppose there was a man whose life was as interesting as could be hoped, and he had a companion who was given to writing. Could that companion refrain from biography? A Boswell to Johnson relationship? I doubt it. But again, suppose that the principal involved eschewed this kind of aggrandizing publicity, for any number of reasons, and forbade his companion to publish. What could they do? One solution would be to publish the biography as a fictional account, using fictional names but actual events.

“I contend that in this theory lies the root of truth in our more celebrated detective heroes.” He paused and relit his pipe.

“You’re not saying that you think Holmes actually existed?” I said.

“Precisely, John, precisely.”

Arrowroot spoke up. “It’s not a new theory at all. As far back as 1900, readers were proposing it. Holmes was still alive at that time, remember.”

“But a man of his supposed stature?” I protested. “I should think that, even fictionalized, he’d be immediately recognizable to the public.”

“James Bond isn’t,” Kevin said.

“James Bond! Come on.”

They shrugged at one another. “It’s been established that he’s alive and working right now. Of course, though it hurts to admit it, Fleming was better at peripherals than Conan Doyle.”