The Battle of the Labyrinth is an American fantasy-adventure novel based on Greek mythology written by Rick Riordan. It is the fourth novel in the Percy Jackson & the Olympians series. The novel was first published in the United States on 6 May 2008 by Hyperion Books for Children, an imprint of Disney Publishing Worldwide. It has been published in hardcover, audiobook, ebook, and large-print editions. To date, The Battle of the Labyrinth has been translated into 29 languages from its original English. The book follows the adventures of modern-day fourteen-year-old demigod Percy Jackson, the son of a mortal woman and the Greek god Poseidon. Percy and his friends Annabeth Chase, Grover Underwood, Rachel Dare and Tyson attempt to stop Luke Castellan and his army from invading Camp Half-Blood through Daedalus's labyrinth by trying to prevent the Ariadne's string from falling into his hands. The Battle of the Labyrinth received mostly positive reviews, with critics praising the storyline, humor and action present in the novel. The novel was on the Amazon Children's bestseller list and Publishers Weekly Facts and Figures bestseller list. It was also the runner-up for the 2010 Indian Paintbrush Book Award. Source: Wikipedia (en)