The Diary of Luke Castellan
When Thalia was twelve, she ran away from home in Los Angeles and discovered Amaltheia. She followed her, seeing the goat as a sign from Zeus. She was lured to a dragon's cave where she met Luke Castellan. Later, Amaltheia would reappear in Richmond, Virginia, where she would lead Thalia and Luke to a mansion which held a treasure for Thalia, which turned out to be a deadly trap. But with the help of Luke, Thalia discovered Amaltheia had lead her to a gift from Zeus, Aegis, which she was able to use to battle the Leucrotae and save Luke.