User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-117.198.156.12-20121021135521/@comment-5112532-20121021192226

Nico seems like a logical choice since he is now on the Argo II, heading for the House of Hades, and then we can learn about what happened in Tartarus.

BUT, if The Mark of Athena was all Greek POVs, then The House of Hades will most likely be full of Roman POVs. So that means Frank, Hazel, Jason and someone on the Roman side, who can tell us what is happening with the attack of Camp Half Blood. I hope it will be Reyna (!!), because I think she is a really interesting character - she's been rejected by Jason and Percy, is fighting a war of her own against Octavian and his minions, whilst trying to lead Camp Jupiter.