The City of Ember: Graphic Novel by Jeanne DePrau
In the year 241, twelve-year-old Lina trades jobs on Assignment Day to be a Messenger to run to new places in her decaying but beloved city, perhaps even to glimpse Unknown Regions.
Review from Booklist Reviews:
Ember, a 241-year-old, ruined domed city surrounded by a dark unknown, was built to ensure that humans would continue to exist on Earth, and the instructions for getting out have been lost and forgotten. On Assignment Day, 12-year-olds leave school and receive their lifetime job assignments. Lina Mayfleet becomes a messenger, and her friend Doon Harrow ends up in the Pipeworks beneath the city, where the failing electric generator has been ineffectually patched together. Both Lina and Doon are convinced that their survival means finding a way out of the city, and after Lina discovers pieces of the instructions, she and Doon work together to interpret the fragmented document. Life in this post-holocaust city is well limned-the frequent blackouts, the food shortage, the public panic, the search for answers, and the actions of the powerful, who are taking selfish advantage of the situation. Readers will relate to Lina and Doon's resourcefulness and courage in the face of ominous odds.