“Good thought,” I murmured.

“There’s more.”

She reached into her bag and brought out a thirteenth-century book wrapped in acid-free paper. She placed it on the coffee table and donned a pair of latex gloves to unwrap it. “This is Lord Volescamper’s copy of St. Zvlkx’s Book of Revealments. It wasn’t one of the books that was vandalized by our mystery book damagers. I had a look under UV light, and I can just see the original text beneath St. Zvlkx’s prophecies. I’m thinking that all St. Zvlkx’s original works were written on recycled vellum.”

“Any idea of the source book?”

She smiled. “Let’s see how good you are, Chief Librarian.” She opened the book at a marked page and pushed it across.

I looked closely. There was some text written sideways beneath St. Zvlkx’s Second Revealment, the one predicting the Spanish Armada, or, as he called it the “Sail of the Century.”

“It looks like a copy of the Venerable Keith’s Principia Accounticia.” I murmured, and Phoebe was suitably impressed. The Venerable Keith had been a contemporary of St. Zvlkx’s and also the accountant for the bishop of Swindon between 1276 and 1294. The Evadum, as it was known, explained the new science of utilizing loss-making companies to offset tax liability against profit. Monks couldn’t hand-copy them fast enough.

“There were lots of copies,” I said, “which was probably why St. Zvlkx could buy them up cheap to scrape clean and rebind in order to peddle his own rubbish.”

“I agree,” said Phoebe, producing another book, this time Zvlkx’s treatise on herbal remedies for “unwonted flaccidity,” A Short Historie of Thyme.

I stared at the two books. It still didn’t tell us why Jack Schitt and Goliath were destroying parts of worthless thirteen century books, even if they did have palimpsests of almost equally banal titles beneath them. Still, I was seeing the Goliath rep next, so it was possible I could rattle that tree a bit and see what fell out.

“I know,” said Phoebe, sensing my confusion. “Doesn’t make much sense, does it?”

I picked up the phone, punched a button and asked to be put through to Finisterre.

“You’re right, it makes no sense at all,” I said to Phoebe. “But at least we know what they’re after. . . . James? Thursday. I’ve got Detective Smalls here, and she’s found a link between the vandalizations. . . . St. Zvlkx books. There have been three including the one at the Lobsterhood. Place the library’s copies under armed guard.”

I put the phone down, and Smalls got up.

“I hope I’ve been candid,” she said.

“Very.”

“In that case perhaps you can tell me who was in the scriptorium yesterday? I think you’re not telling me everything you know.”