"Same reason they animate humans instead of animals," I said. "Older corpses leave a deeper metaphysical imprint. They're harder to call up, but once you get them here they're easier to control, stronger, more difficult to damage."

"Old corpses get you stronger undead flunkies," he said.

"Right," I said. I could see the wheels turning in Butters's head as he processed the information. He looked like he was busy lining up dozens more questions spawned by the answers to the first few, and I had a feeling he would pursue them with relentless curiosity.

"Okay. But what if—"

"Butters," I said as gently as I could. "Not now. All I want to do is have a quiet cup of tea." An inspiration hit me. "Ask Bob," I told him. "Bob knows a hell of a lot more than I do, anyway."

"Oh," Butters said. He looked from me to the skull. "Um. Yeah, I guess Thomas was talking to it."

"He!" Bob said indignantly. "I am very much a he! I'm not some kind of freaking animatronic Tinkertoy!"

"Right," Butters said. "Um. Sorry. Bob. Do you mind if I ask you some questions?"

"It's a waste of my vast intellect and talent," Bob sneered.

"Do it, Bob," I told him.

"Oh, man." The orange lights in the skull's eye sockets rolled. "Fine. I haven't got anything better to do than to teach kindergarten."

"Great!" Butters bubbled, and sat down at the table. He grabbed some more paper and a pencil. "Well, how about we start with…"

I fixed myself a cup of tea and one for Butters. I put the cup down near him, but he took little notice of it. He was deeply involved in a conversation with Bob.

I slipped out into the living room and put my aching leg up on the table, then settled back onto the couch with my tea. I sat in the gloom, sipping hot, sweet mint something-or-other and tried to order my thoughts. I was tired enough that it didn't take too long.

I was about to call up a peer of Queen Mab and try to trap it for an entire night. A garden spider had about as much chance of trapping a Bengal tiger. Except that the Bengal tiger probably wouldn't bother to squash the spider for daring to make the attempt. The Erlking would.