Annabeth Chase
Annabeth, Percy and Tyson, having not been allowed to go on the quest for the Golden Fleece to save Thalia's Pine Tree and find Grover by Chiron's temporary replacement, sneak out of Camp Half-Blood to do so. During the book it is revealed that Annabeth's greatest dream is to redesign the whole world to improve it, save Luke (from himself), and be accepted by her mother and father. After getting stranded on the island of the Queen-Witch Circe, Annabeth saves Percy after he is turned into a Guinea Pig using the multivitamins given to them by Hermes. During the fight with Polyphemus Annabeth (while invisible with the use of her Yankee's Cap) pretends to be Nobody and distracts him long enough for Percy to vanquish him. Annabeth is injured fatally during the fight but is healed with the help of the Golden Fleece.