Well, Peter Lerangis managed to pull it off. After Seven Wonders #3 and #4, my interest in the series had seriously begun to decline. But Lerangis pulled it all together in this final run. I actually had trouble putting it down, which is saying something. It was fast-paced, energetic, and emotional. There was a real sense of urgency to the book which you shared with the characters; whenever something went wrong, I felt the same frustration that the characters did. This sympathy also extends to the characters' struggles with trust. The uneasiness which came with the alliance between the Karai Institute and their long-time enemies the Massarym was felt throughout the entirety of their interactions. The book ends with a satisfactory and surprising ending which I honestly think was probably one of the only ways it could have concluded. I gave a number of answers, but still left some questions open for the reader to interpret.
Jack, the protagonist, developed the most in this book. His leadership abilities, present throughout the entire book, were finally realized by himself and others. However, some aspects of his character, such as his whole claim to the Atlantian throne, were left up in the air with little direct resolution. Overall though, he developed well enough to satisfy the reader in the end.
Marco and Cass had little development, but they developed enough in the previous four books to warrant their neglect in this one. Two characters who actually suffered from Lerangis' neglect were Eloise and Aly. Eloise remained a static and unchanging character, with little to redeem her aggravating nature. This could be explained by her being more of a child than the rest of the cast, but if this was a case, her role should have been less prominent. Aly suffered the most, though. She was a fantastic character with great relationships in the previous book, and her absence through the majority of the book is sorely felt. However, when she does make a return, that hole is never filled. She returns to the story, but never returns to that place of prominence she held throughout the rest of the book.
Overall, Lerangis managed to pull things together to end his series in a satisfying manner. Though I complained of Eloise and Aly, the main focus of most of the book is on Jack, Cass, and Marco. Those three characters carry this story to a great conclusion to a good series. I'd recommend this series highly, not only to the younger audiences, but to older ones as well. It was a breath of fresh air to me, and I think it will be to others as well.