"I didn't expect you to," Dr. Lecter says. "But the principles you need are all in there. Arches, supports, cranes, vaults, tools, beams, the lot. That one, you can keep. Whenever I come across a copy in a used book store, I pick it up because I keep giving it away."

He wanders on, and throws another book at Javert. It's about late medieval churches in northern France, published in the 1820s.

"That one, I definitely need back."