<P> It is the first "Book of Ember" in the eponymous series, which also includes The People of Sparks, The Prophet of Yonwood (a prequel), and the final installment, The Diamond of Darkhold . In 2008, the book was adapted into a film by Walden Media and Playtone . </P> <P> A graphic novel adaptation by comic book artist Niklas Asker was released on September 25, 2012 . </P> <P> As the book stats off a coalition of architects, scientists, and doctors known as "The Builders" have assembled Ember, a subterranean city with supplies for its inhabitants to survive at least 200 years, to elude an impending disaster . They handed the first mayor of the city a locked box, holding instructions for the city's inhabitants, to be passed down from one mayor to the next . This passage continues until the seventh mayor who, in search of a cure for a deadly cough tries multiple times to break it open but fails each time, then dies before he can return the box to its rightful place or inform anyone else of its importance . Two hundred forty - one years after Ember is established, the city ′ s supplies are in danger of exhaustion and its hydroelectric generator is in decay . At their graduation ceremony, young people are assigned their jobs: Lina Mayfleet is assigned the job of "Pipeworks Laborer" and Doon Harrow is given the job of "Messenger ." However, both are displeased with their assigned jobs so they exchange their assignments in secret . Lina's younger sister, Poppy, exposes the instructions left by the Builders, but in teething leaves them almost illegible . Later, Lina asks Doon to help her reconstruct the paper . After much trial and error, she and Doon decipher the instructions from the Builders, which inform them of how to exit the city of Ember . Lina's grandmother dies shortly afterward, and Lina and Poppy move in with a neighbor, Mrs. Murdo . At work, Doon discovers that the mayor of Ember and a storeroom worker named Looper have been stealing supplies, and he and Lina report the crime . Upon following the instructions given in the note, they discover boats and candles meant for use in the exodus . On their return to Ember, they learn that the mayor has declared them fugitives from the law . Lina is arrested and taken to the mayor, who threatens to throw her in jail . Suddenly, a blackout occurs and allows her to escape without being seen . Lina, Doon, and Poppy escape in a boat through the river that supplies Ember's electricity . When the boat stops, they learn the origin of Ember from a diary left by one of its original colonists . Shortly after they are faced with a very steep climb and emerge onto the surface where they see their city from above and realize for the first time that Ember is underground . They throw a rock with instructions tied to it down to the city in hope that the people of Ember will escape . The novel ends with Mrs. Murdo finding the message on the street . </P> <P> The City of Ember was praised for its setting and main characters, Lina Mayfleet and Doon Harrow . Kirkus Reviews praised the characters finding them "likable" for their courage, but also for their flaws of human pride . The reviewer noted how "their weaknesses often complementing each other in interesting ways". Sally Estes from Booklist commented how readers would be able to connect to Lina and Doon's courage amidst the conflicts . Robert Sutton from Horn Book Magazine compared the novel to Gathering Blue by Lois Lowry, noting how "the darkness of Ember is essentially literal" with the generator (the mechanical light operator) failing and running out of power, leading to frequent blackouts . Sutton noted how DuPrau does not explain the history of Ember all at once, which would confuse and overwhelm the reader and instead, "allows the events of the story to convey the necessary information". Lina and Doon were described as "good sorts" that are "deeply etched". Dian Roback from Publishers Weekly also praised the "full blooded characters" as every bit as good as the plot which would hook readers until the end . Although Jones Johns from School Library Journal wrote that the setting was not as ingenious as the ones in Joan Aiken's Is and Lois Lowry's The Giver, he said that the characters and pace of the plot would keep readers hooked . </P>

Where does the city of ember get its light from
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