I carefully emptied the packing case. There were six more books that I recognized as being authentically related to magic, all of them with the BIBLIOTHECA BODLEIANA library stamp.

I assumed that stamp referred to the Bodleian Library, which I vaguely remembered was in Oxford, but while I didn’t recognize the second stamp I did recognize the motto. I dialed the Folly. The phone rang several times before being picked up. “It’s Peter,” I said. There was silence at the other end. “I need to speak to him right away.” I heard a clunk as the receiver was put down by the phone. As I waited I thought it was about time that I bought Nightingale a proper phone.

When Nightingale picked up I explained about the books. He made me list the titles and describe the stamps. Then he asked if Stephanopoulis was available.

I called her and offered her the phone. “My governor wants a word,” I said.

While they talked I started bagging the books and filling out the evidence tags.

“And you think this makes it more likely?” she asked. “Fair enough. I’ll send the boy over with the books. I expect you to maintain chain of custody.” Nightingale must have assured her that we would be as scrupulous as any Home Office lab because she nodded and handed the phone back to me.

“I think,” said Nightingale, “that we may be dealing with a black magician here.”

Chapter 5 - The Night Gate

BLACK MAGIC, as defined by Nightingale, was the use of magic in such a way as to cause breach of the peace. I pointed out that a definition like that was so broad as to essentially include any use of magic outside of that authorized by the Folly. Nightingale indicated that he regarded that as a feature, not a bug.

“Black magic is the use of the art to cause injury to another person,” he’d then said. “Do you like that definition better?”

“We don’t have any evidence that Jason Dunlop ever did any injury to anyone through the use of black magic,” I said. We’d laid out the case files on a table in the breakfast room along with the books I’d brought back from Dunlop’s flat and the remains of Molly’s eccentric stab in the direction of eggs Benedict.

“I’d say we have a fairly clear indication that somebody did him injury,” said Nightingale. “And strong evidence that he was a practitioner. Given the unusual nature of his assailant I think it’s a safe bet that magic was involved—don’t you?”

“In that case isn’t it possible that the Jason Dunlop murder is related to my dead jazz musicians?”

“It’s possible,” said Nightingale. “But the MOs are very different. I think it’s better to keep the two investigations distinct for the moment.” He reached out to where one of the Folly’s monogrammed Sheffield steel forks was jammed upright into a poached egg and flicked it with his finger—it barely moved. “Are you sure it’s not stuck in the muffin?”