User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-4902593-20130108120716

Guys, what I think Leo (in the last chapter) was referring is that even if they succeeded in closing the Doors Of Death on both sides, how could Percy and Annabeth suceed in getting out of Tartarus? If RR wants them back, he would make sure they're back. (Besides I feel sorry for Percy for not being able to see his home soon). So who knows, House Of Hades might have a happy ending, for the moment of course. Or maybe I am being optimistic.

Opinoins are welcome.