 Riordan's first full-length novel was "Big Red Tequila", which became the first book in the "Tres Navarre" series.His big breakthrough was "The Lightning Thief" (2005), the first novel in the five-volume "Percy Jackson and the Olympians" series, which placed a group of adolescents in a Greco-Roman mythological setting.Since then, Riordan has written "The Kane Chronicles" trilogy and "The Heroes of Olympus" series.