The City of Ember is a post-apocalyptic novel by Jeanne DuPrau that was published in 2003. The story is about Ember, a post-apocalyptic underground city threatened by aging infrastructure and corruption. The young protagonist, Lina Mayfleet, and her friend, Doon Harrow (the second protagonist), follow clues left behind by the original builders of the City of Ember, to safety in the outside world. It is the first book in the Books of Ember 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. A graphic novel adaptation by comic book artist Niklas Asker was released on September 25, 2012. Plot As Earth is being ravaged by a series of apocalyptic events known as the Disaster, a coalition of architects, scientists, and doctors (called the Builders) create an underground city named Ember, with an initial population of 200 citizens (100 elderly adults, 100 babies), to ensure humanity survives, with the intention that future generations of the city will not know about the outside world or that they live underground. They build the city to last for two centuries, after which the citizens of Ember will evacuate and return to the surface world. The Builders give the first mayor of the city a box with a timed lock set to open after 200 years, containing instructions explaining how to leave Ember; the box is passed successfully from mayor to mayor, until the seventh mayor, who, thinking the box might contain a cure for the deadly cough disease plaguing the city, takes the box home and tries multiple times to break it open, but fails. He then dies before he can return the box to its rightful place or inform the next mayor of its importance. Approximately two hundred and forty-one years after Ember is established, the city′s supplies are in danger of exhaustion and its hydroelectric generator is in decay, causing the power to go out intermittently. At their graduation ceremony, young people are assigned jobs by lottery: 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 and begin work in their respective positions. It is revealed that the seventh mayor was Lina's great-great