Original: After being attacked by empousai cheerleaders at his new school, Percy returns to Camp Half-Blood and learns about the Labyrinth; part of the palace of King Minos in Crete that was designed by Daedalus.
Simplified: After being attacked by Empousai cheerleaders at his new school, Percy returns to Camp Half-Blood and learns about "The Labyrinth", part of the palace of King Minos in Crete that, according to Greek mythology, was designed by Daedalus.