User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-17110564-20130901011530/@comment-10750309-20130901021646

Well we'll get some scenes from Tartarus, maybe either by Katoptris or demigod dreams or maybe either Percy or Annabeth will have POV. But I think it will be much better if they give either Percy or Annabeth a POV, just to know what are they doing while the other demigods go to Epirus. If you ever read The Kane Chronicles (esp. Serpent's Shadow), the two siblings Carter and Sadie eventually split up to do specific stuff and they just converge at a later part of the book. I think this will be the case in Book 4.

As to why Percy and Annabeth are on the cover, Percy and Annabeth falling to Tartarus is the highlight of MoA, or the most talked about, so it is just right to make them the cover, just to assure fans that they are still alive. And we still don't have any Percabeth cover yet, but know we have one.