User blog comment:Misakichii/Which Demigod will lead the 7 to the Doors of Death?/@comment-121.54.58.131-20111031111446

I think its Annabeth. Ella mentioned 'Mark of Athena burns through Rome' and it implies to the 3rd book plus Annabeth is the only noticeable child of Athena in the first series so she is the seventh demigod in the prophecy(I'm quite sure that Athena is the parent of the 7th) so the Door or Death are in Rome (Nico was captured in there for searching the Doors of Death) and the 'guide' Thanatos mentioned is probably Annabeth. Anyways, RR might put a twist on the story and let's just wait for the 3rd book to come out.

P.S...Aside from me, does anybody remember that Daedalus has the Mark of Athena, maybe Rick's gonna revive the labyrinth in the 3rd book, but a guide?, Rachel's job...Let's wit for another year