User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-184.100.137.67-20130630022140/@comment-10750309-20130706225102

I doubt that. I really think that none of the seven will die on Book 4. If there will be someone to die on the seven its gonna happen at Book 5. (Seriously, they need all the exposure they can have)

One more thing, being the seventh wheel doesn't mean that your gonna be the one to die. True, Nemesis said that Leo will be the Seventh wheel, but it maybe romantically (LOL). For this to happen and not to have a Lezel:

1) Frank and Hazel will die

2) Only Hazel will die

3) Frazel wins over Lezel

So my bet on closing the Doors is Nico (some say it will be Hedge). But if it is not Nico and not any of the Seven, GREAT!