Charlie Bone is worried about his friend, Billy Raven. Billy, an albino and an orphan, has longed for a family of his own and it seems like his wish has come true when Mr. and Mrs. de Grey agree to adopt him. Charlie is happy for Billy, but the de Grey's are friends of the Bloor family and Charlie doesn't trust them. Charlie is right to be worried - the de Grey's have powers that literally won't let Billy leave the house unless he is going to school. Charlie, his Uncle Paton, and his friends all try to find a way to get Billy out of the de Grey's house and to a place where he'll be safe. Charlie also wonders what is going on at his school Bloor's Academy. Piano teacher Mr. Pilgrim is gone and his replacement, Tantalus Ebony, is a bit odd. Charlie also wonders what's up with a new student, Joshua Tilpin, who seems to be magnetic. Charlie also wonders why his friend Olivia is acting so strange. On top of it all, Charlie keeps searching for his missing father.
"Charlie Bone and the Castle of Mirrors" certainly has its good points. For one thing, some of the children grow as characters, especially Billy and Olivia. Author Jenny Nimmo also shows some increasing aspects of Charlie's ability to read the thoughts of people in photographs and pictures. There's a nice sense of humor throughout the book, with some punny word play and an especially funny scene at the Pet's Café. The fantasy elements are nicely done, especially the introduction of Alice Angel, and a wonderfully imaginative scene involving written oaths coming alive and attacking Charlie and his friends. The "flames" as always, add much to the fantasy elements.
However, the book has its flaws. While some characters are well developed, other characters aren't developed at all. Once again Nimmo awkwardly gets rid of characters without any real explanation as to why they are gone. New characters that are added are underdeveloped, especially Joshua Tilpin and Tantalus Ebony. With the exception of Uncle Paton, most of the "good" adults are once again useless, especially Charlie's mother, Amy. Charlie's life at school is not particularly well-written - it's not clear what classes he takes and what classes many of the teachers actually teach. One plotline - losing balance - was very interesting, but felt thrown in at the last moment and could have been much more developed. The ongoing plot line of Charlie looking for his father could have been plotted and written better since it's obvious who his father really is.
The Children of the Red King series is a quick, at times enjoyable read, but continues to be somewhat frustrating.