I explained the situation, but he was shaking his head even before I finished. “What makes you think I would be so foolish and trusting, to place myself into the hands of my long-time enemies? More importantly, even if you could manage to convince me of my safety, why should I go to the one place where I would never be allowed to kill? I must murder, Edwin. It is my nature.”

“After the tutoring is done,” I said, “you can murder as many Loathly Ones as you like.”

“The Droods have opened up their old library,” said Molly. “Packed full of forgotten and forbidden texts from centuries back. Somewhere in that Library there must be information on how to . . . if not reverse, at least moderate the conditions of your immortality. Give you some control over it. So you wouldn’t have to kill all the time.”

Mr. Stab considered her thoughtfully. “And what makes you think I want that?”

“Because you’ve refrained from killing me, and my friends,” said Molly. “And I’ve never known you do that for anyone else.”

He nodded slowly. “You want me to do this thing, Molly? Even though you must know it can only end in tears?”

“I want you to do this, so it won’t,” said Molly.

“Then so be it,” said Mr. Stab.

I opened the Merlin Glass to the Armoury, and waved Mr. Stab through. He was greeted by a very harried-looking Armourer, and I shut the mirror down quickly before Uncle Jack could say anything. He looked very much like he wanted to say something, but I was pretty sure it wasn’t anything I wanted to hear. I put the Glass away and turned to Molly.

“I think we’ve done enough for one day, don’t you? I think we’re owed a little downtime, before we have to report back. What shall we do?”

“Well,” said Molly, linking her arm through mine, “I did promise you a good meal, and since we’re in London for the evening . . . What say we take in a West End show, and have dinner afterwards at the Ritz?”

“Sounds good to me,” I said. “But we’ll never get tickets for anything decent at such short notice.”

“I’m a witch, sweetie, remember? Trust me, tickets are not going to be a problem.”