The book begins with Percy Jackson going to a freshmen orientation class at Goode High School, a school where Paul Blofis, his mom's boyfriend, teaches. While there, he meets Rachel Elizabeth Dare, a clear-sighted mortal whom he met previously at the Hoover Dam in The Titan's Curse. During the orientation, Rachel suddenly runs away to the gym. Percy follows her, and she tells him that something is wrong with the two presenting cheerleaders, Tammi and Kelli.
