In this book, it ends off The Heros of Olympus series. This whole series is amazing but, the Blood of Olympus is probably my favorite book in the entire series. Like all the other books, it picks up where the series left off. They have closed the doors of death but now still need to defeat Gaea. The gods are having multiple personality disorder because their Roman and Greek sides are warring with each other. This is because the Roman and Greek demigods are at war with each other. The demigods have split up. The first seven are still together but Nico, Reyna, and Coach Hedge are shadow traveling the Athena Parthenos to Camp Half-blood to stop the war. Meanwhile, the seven are looking for clues on how to defeat Gaea and destroy the giants without the gods help. Nico, Reyna, and Coach Hedge are able to get the Athena Parthenos to Camp Half-blood and stop the war. The Seven come just in time after defeating the giants. But are they able to defeat Gaea?
Bottom line: This book is actually less scary then the last two because they are no longer in the underworld for half the book. As I said before I LOVE this book. One of the best I have ever read. I think it is for 5th and older but well educated 4th graders could read it. Although, if you go by what I say your well educated 4th grader would have to miss two books in the series which would not work, so I do not really know what to do about that one.