Richard Russell "Rick" Riordan, Jr. (born June 5, 1964) is an American author best known for the "Percy Jackson and the Olympians" series. He also wrote the "Tres Navarre" mystery series for adults and helped to edit "Demigods and Monsters", a collection of essays on the topic of his Percy Jackson series. He helped develop the 10 books in "The 39 Clues" series, published by Scholastic Corporation, and wrote the first book in the series, "The Maze of Bones".