User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-173.75.230.82-20121022195354

This is not really a prediction, more an observation about the book. On page 317 of The Last Olympian, Hades, talking to Kronos, says "Now fight me! For today the House of Hades will be called the saviors of Olympus." This could have some connection to the House of Hades book, but it seems more likely to me that it is simply a coincidence, as Hades appears to be referring to his family and subjects, not an underground temple in Epirus.