The Battle of the Labyrinth, Rick Riordan, Hyperion Books, 2008.
This book was my favorite in the Percy Jackson series -- so far, anyway. Rick Riordan has no trouble tapping into the mind and psyche of a fourteen, almost fifteen-year-old boy.
There are still parts of the book that drove me a little crazy, for example the search for Ariadne's thread. Um, wouldn't that be the same Ariadne who is married to Dionysus, who is the same Dionysus who is a counselor at the Half-Blood Camp? Hmmm. The Quintus part was a nice twist, although not unexpected. And the fading of Pan was beautifully done.