Garth Nix, "Lady Friday (Keys to the Kingdom, Book 5)"

As with other books in the series, this story is replete with characters that are good, bad, and ambiguous. The plot is complex, and readers need to read the four previous books to have any sense of what is going on in this one. As always, Nix's writing is witty and the plays on words are entertaining. The author gives just enough new information to keep the series' fans coming back for more, but he doesn't answer many questions.