This series is starting to pay off in a much bigger way. There is a pretty major dying off in this volume and Percy, Annabeth and Grover definitely show some growth and maturity. Nico is a tad unbelievable. He seems almost the same age as Percy and Annabeth and once again I found myself forcibly reminding myself that he was like 10. That aside, the story continues to be enjoyable and things are building quite nicely. In a lot of ways the villain of the story is similar to Voldemort in the Potter series (some assembly required). But with the Titan King intact again the stage is set for the final volume and I'm really looking forward to it. In longer sereis, the book before the resolution tends to become a placeholder and time-killer, but I think this book served well on it's own. The mysteries of Daedalus's labyrinth, Annabeth's prophecy and the identity of the informant within Camp Half-Blood keep things interesting. The ending was less startling than in the previous books, but I think that's because by the end of this volume, you know where the series is going: everything has been building to Percy's 16th birthday and the fulfillment of Chiron's prophecy. I liked the introduction of Ms. Dare to the series and I hope they don't do to her what they did to Thalia and have her just disappear in the next volume. She added just enough tension to the relationship between the familiars to keep the interpersonal developments as interesting as the plot. This is a wonderful series for kids!