House of Many Ways - Diana Wynne Jones
I discovered DWJ late on (as in, not when I was within her originally intended audience) and fell utterly in love with her books, to the point where she's the only author I will pre-order in hardback. As for House of Many Ways, it's a much-awaited follow-up to Howl's Moving Castle (if you ignore what is really just a cameo appearance for both Howl and Sophie's in Castle in the Air) which is a book I love immensely and have re-read multiple times.

The plot essentially centres on Charmain Baker, a teenage girl who is asked by a distant relative (who just happens to be a wizard) to look after his house while he's away being looked after by the elves. His house is, of course, magical and connects with various places, including the royal palace. Assisted by an apprentice her uncle had forgotten was coming, not to mention Sophie and an oddly-different version of Howl, Charmain becomes involved in the mystery of where the royal gold has disappeared to.

While not as good as the original book in the series, I really enjoyed House of Many Ways, though I probably found Howl almost as trying as Sophie does at times. Hopefully DWJ will have some more sequels in mind for Howl and co., though I'm usually more than happy with whatever she writes!