User blog comment:Maimer1882/Annabeth is a part of the 7/@comment-4577711-20111104102020

Hmm.. the major characters in HoO kind of fit with the Seven.

1. Percy 2. Hazel 3. Frank. 4. Jason 5. Piper 6. Leo 7. Annabeth

Unless of course, Rick adds another character in the later books.. D: