The City of Ember

The City of Ember by, Jeanne DuPrau. ISBN-13: 978-0375822735

Deep under the earth, exists a mysterious city named Ember. As far as the city's inhabitants know, they are the only life that exists. Unfortunately, things in their city are starting to fall apart. As the vasts storerooms for supplies become more and more empty, Doon Harrow and Lina Mayfleet begin to realize that Ember faces certain doom and that they might be the only two able to stop it.