User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-153.107.97.161-20121026024143

Maybe Nico is the one with the entire oath to keep with a final death thing...

He will lead the other 5 to the doors of death but when they arrive he will go the other side and close them. Percy won';t let this as he and Nico are close but Frank steps in and does his duty.