“Molly Metcalf said I might find answers here,” said Mr. Stab. They might have been discussing the weather. “Old knowledge, unavailable anywhere else. Perhaps even the means to a cure for my condition. Or at least, to ameliorate certain aspects of it.”

William considered him thoughtfully. “You chose to make yourself what you are. Have you now come to regret it?”

“You know this library better than anyone,” said Mr. Stab. “Can you help me?”

“Why should I?” William said bluntly. “After all you’ve done, why shouldn’t I delight in the prospect of your inevitable descent into Hell?”

“To save future lives?” Mr. Stab said calmly. “So that there might be no more Pennys, and no more Rafes.”

William sniffed. “I suppose there might be something here. We have books on every subject under several suns; from the unusual to the improbable, the unlikely to the downright impossible. I’m pretty sure you’re in there somewhere. It depends . . . on exactly what it is you want me to find.”

“I made myself what I am,” said Mr. Stab. “Everything I am and everything I have ever done . . . is my responsibility. But for the first time . . . I wish to change things.”

“That would depend on who or what you made your original deal with,” William said carefully. “Some deals can be . . . renegotiated. Do you wish to become human again?”

“I’ve always been human,” said Mr. Stab. “That’s the problem. I want . . . something else. I want to find a way to bring back my victims. All of them. To raise from the dead all the woman I have slaughtered, down the many years, and give them life again. Right back to those five poor women who made it all possible, back in that unseasonably hot autumn of 1888.”

“I’m sorry,” said William. “But it can’t be done.”

Mr. Stab surged forward impossibly quickly, a long, gleaming blade suddenly in his hand. Before William could even react, the razor-sharp edge was pressed against his throat, just above his Adam’s apple. Mr. Stab stared coldly into William’s face, his cold breath beating on William’s wide-open eyes. The blade pressed against the skin of his throat, and a single slow trickle of blood ran down his neck as the skin parted just a little under the sharp edge. William sat very still.

“That is not the answer I wanted to hear,” said Mr. Stab.

“We all have things in our life that we would wish undone,” William said carefully. He clearly wanted very much to swallow, but didn’t dare. “But sins can never be undone. Only pardoned.”

“It’s not enough,” said Mr. Stab.