User blog comment:SayuriDarling/The Blood of Olympus Official Discussion/@comment-24055022-20141010142356/@comment-25602244-20141031042043

Hard to say. Both are good. But PJO is where we first met Percy, Annabeth, and Camp Half Blood. It's where it all started. On the other hand, HoO is when we meet the Romans and a whole lot of new characters. So maybe PJO