If there is one lesson to be learned from this story, it is this: never annoy a librarian. Do not even irritate one, not even if you are a demon, an arch-fiend of Hell. And never forget the power of recalling an inter-library loan. Librarians have ways of dealing with even the most difficult, the most powerful of demons. All you have to do is remember Giles, in Buffy the Vampire Slayer.