Bazillionth Percy Jackson book.

I've read so many Percy Jackson books that I've lost count.  Of course Rick Riordan couldn't leave things nice and tidy with the first series - he had to throw in the Romans too! 

This book was much like the others in that I read it in like three days, was not at all surprised, and will read the next one when it comes out.  

I honestly can't figure out why I like these books.  I'm a big Greek mythology fan, and seeing how he interprets gods and goddesses into modern forms is fun.  But otherwise, I'm just not sure. 

CONCLUSION: When is the next one coming out again?