User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-58.106.236.75-20121204101115

I think in the house of hades percabeth will make their way to the doors of death and nico and the others vice versa. However, once they close the doors someone has to stay behind. I think this wont be nico as he is already heavily scarred. Percy wont be able to sacrifice someone but Frank will set things straight. someone will appear to die but at the last moment, there will be some sort of trick that helps them cheat death. After they close the doors, the next book will be fighting the giants (who dont have the advantage of the doors of death anymore) and restoring the romans and greeks hostility using the athena parthenos.