User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-5564284-20121020202118/@comment-5173253-20121020222037

Since Jason, Hazel, Frank, and Annabeth have only narrated once, I think that it will be them. I'm also guessing that book 5 will have all 7 narrate. That would means everyone gets 3 turns