Blood of Olympus by Rick Riordan

Roman and Greek demigods are working together before Gaea, the Earth Mother can awaken.  It is a good thing as the gods are confused and are at war with themselves, struggling between their Greek and Roman aspects.

You know the drill, a quest, fights against giants, monsters, etc.  The best part though is the character development and the way things end for Nico made the book perfect. Pick it up and read it but of course it is better read in order of the series. ;)

The House of Hades by Rick Riordan

Book Four of the Heroes of Olympus

Greek and Roman demigods work together trying to defeat Gaea, the Earth Mother, before she wakes.  A quest, prophecies, random minor gods, you know the drill.

What I really liked is how the character of Nico de Angelo really develops along with Frank Zang, without either one doing anything on purpose.  Expect to see more from these two.

If more is told to much is given away, you just have to read it for yourself.

Mark of Athena

A wonderful blending of Greek and Roman mythology with that nice twist that Rick Riordan puts into his novels.  A sense of maturity comes from the main characters, something that has been developing throughout the series but is almost a focus in the current novel.

The changing narrarator keeps things moving along and helps the reader to view the story from multiple perspectives which puts a spin on a couple of incidents. 

My major complaint is we are left once again with a cliffhanger with the next page stating Coming in Ocotober 2013.  This is then followed by a really nice glossary of terms and characters which I had thought was another chapter of pages. 

Just let me know the pre-order date and I will buy in. :)