Raguel

"Yep," Crowley says confidently. "He'll use everything but outright violence to avoid having to sell a book, but give him a fresh mind ready to be illuminated by the great wordsmiths et cetera, et cetera, and he can't give them away fast enough. You have to take good care of them, though," he adds after a moment. "He always knows if you've been dog-earing pages, and that. It's sort of creepy."