This is the fourth book in the Heroes of Olympus series by Riordan. The fifth (and final) book in this series will be titled, Blood of Olympus, and is scheduled for an October 2014 release date. I thought this book was by far the best yet in the Heroes of Olympus series and I really enjoyed it.
I listened to this on audiobook and the audiobook was very well done. The narrator does a decent job of distinguishing between all of these different character voices and of conveying character emotion.
Annabeth and Percy were thrown into Tartarus at the end of the last book and they are struggling to survive there and to find the Doors of Death. The other five Demi-Gods (Leo, Frank, Jason, Piper, and Hazel), with some help from Nico, are following Percys instructions to find the Doors of Death in the mortal realm. Every hero has a part to play and all of them must get more comfortable with their powers if they are going to succeed.
This was an excellently done continuation of this series. There is a ton of of interesting mythology and adventure. In previous books in this series I kind of felt swamped with the multitude of characters but in this book I felt like all the characters were more well balanced. I am finally beginning to engage with and really like the characters.
It doesnt hurt that we get to spend a lot of time with Percy and Annabeth in Tartarus. I love those two characters and watching them support each other through a number of horrific trials and adventures was awesome.
As for our other characters, all of them make some interesting revelations about their powers. Frank comes into his powers as a Demigod of War. Piper learns how to make her charm speak more powerful, Hazel learns how to control the Mists, and Leo gets a tough life lesson in love.
A lot happens in this book and it was all just awesome. There is a lot of action here and a lot of pieces are coming together.
I still think these books are very formulaic and this book still has a bit of that. The characters have to get to the Doors of Death by a certain time, fighting harder and harder monsters along the way, or all will be lost. However, because of the way the plot line switched between Tartarus and the Mortal World it felt a bit less formulaic than the previous books in the series.
Overall I really enjoyed this book a lot and can't wait to read book 6, Blood of Olympus. I finally felt like in this book I was really engaged with the characters. They characters grow a lot in this book and there is a ton of very cool mythology throughout the story. The book is action packed and moves quickly. I really thought this was the best book of these series so far. I highly recommend both Riordan's Percy Jack series and this series to fans of fantasy; especially mythology driven fantasy.