In the book "The son of Neptune", I noticed a few lines about Percy's fate, and how it *could* work out. The lines are:

"Maybe, Maybe so. But every hero has a fatal flaw. Percy Jackson? He's too loyal to his friends. He can't give them up, not for anything. He was told that years ago. And someday soon, he's going to face a sacrifice he can't make. Without you, Frank-- without your sense of duty, he's going to fail. The whole war will go sideways, and Gaea will destroy the world." -Spoken by Ares/Mars, chapter XXXIV

And:

"Then Gaea has already won. I'll tell you this Percy Jackson. The one that will cause you the most trouble is the one that is closest to you--the one that hates me the most" -Spoken by Hera/Juno in chapter LI

To me, this points to a point where Percy will have to sacrifice Annabeth in some way to achieve his goal.

Yep, horrifying thought, but it's about what this points to.

Also, anyone else hating the cliffhanger at the end of The Son of Neptune?