"The Underland Chronicles is a series of five fantasy novels by Suzanne Collins, first published between 2003 and 2007. It tells the story of a boy named Gregor and his adventures in "Underland", a hidden land under New York City. The Underland is inhabited by humans, who live in the stone city of Regalia, along with various giant versions of such creatures as bats, cockroaches, rats, lizards, mice, ants, and spiders. According to the author, the series involves many topics relating to war, including biological warfare, genocide, and military intelligence." (source: Wikipedia)