User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-69.127.161.128-20121113030755/@comment-5593237-20121124015630

Hazel or Frank or both. Hazel is supposed to do something good with her second life and she might risk it to save her friends. Frank might not be able to handle her death so he might go with her. If Frank decides to go (He hasn't really been that useful since The Son of neptune) Hazel won't be able to let him go and we'll go with him.

People who aren't gonna die and why: Percy- The fates show him his death and it shows him dying in old age.

Jason and Leo- They're part of the prophecy (In storm or fire the world must fall)

I think it could be Piper who dies or just not anybodyof the seven as here are five books and in the fourth someone has to go but in the fifth there still needs to be seven.

... Coach Hedge?