"Ptolemy's Gate" is the last book in the "Bartimaeus Trilogy" by Jonathan Stroud. Through out the entire series you hear Bartimaeus lament about the slavery of the demons to magicians, but you really don't think too much about it, because the focus is more on the struggle between the commoners and magicians. In this book that background theme is brought to the front. One of my favorite parts of the book is that we finally learn the story of who Ptolemy was, and what his relationship with Bartimaeus was.
I love the character development that's portrayed in this book, both with Bartimaeus, and with the humans Kitty Jones and Nathaniel. Especially Nathaniel. We already knew that Kitty is a great person, but we've spent the majority of the trilogy hating Nathaniel. In this book he finally begins to see himself for who he really is, and he actually redeems himself by the end of the book!
I really enjoyed this trilogy and I highly recommend it to anyone who loves the fantasy genre. It's written as juvenile fiction, but adults will love it too! I plan on reading more by the author as soon as I can get my hands on it.