The City of Ember (2003) by Jeanne DuPrau is the first science fiction novel in a series for young adult readers called The Book of Ember. The story begins in the mid twenty-first century following a devastating apocalyptic war. The setting is Ember, the sole human settlement that exists in nearly total darkness. Known as “the only light in the dark world,” Ember, too, may soon become completely pitch black. Its aging electrical system, which powers the city’s lamps and floodlights, is showing signs of failure.
The novel begins just after the completion of construction of Ember. Two of the builders realize that the supplies will not last forever and decide to leave detailed instructions for escape in a specially designed box. The box is to be passed on from mayor to mayor, but after a number of years, the box is lost. No one is especially concerned about its location, for no one knew what it contained. The builders had kept the information secret.
The story leaps forward to the year 241 and a graduation ceremony. Lina Mayfleet and Doon Harrow, two of the graduating students, are about to accept their assignments for work in the adult world. The assignments are given randomly; each student draws a slip from a bag held by the mayor. Lina receives “Pipeworks Laborer” and Doon draws “Messenger.” The two friends switch assignments, as the each seems better suited to the other’s job.
When Doon descends into the pipeworks, he tries to find a way to save Ember. He even locates the enormous Generator, but quickly realizes he has no idea how it works, what exactly might be wrong, or how to fix it even if he did locate the problem. Meanwhile, on her jobs as messenger, Lina learns the ins and outs of the city and puzzles over the odd messages she delivers between the Mayor and a strange man named Looper.
When Lina returns to the family apartment after work, her day is not over for she must care for her aging grandmother and little sister, Poppy. One day, Poppy discovers an old piece of paper in a box. Before Lina can examine it, the toddler chews it up and tears it to pieces. Lina saves the scraps and shows them to selected people, hoping to discover its meaning, but no one has any idea how to decode the cryptic message.
Lina will not give up, though, and enlists Doon to help her solve the puzzle. Eventually, the friends discover the message is the instructions for the way to get out of Ember. They must go into the pipeworks to do so. While in the tunnels, Doon and Lina run into Looper, the weird man who had exchanged messages with the Mayor. They find out that he has been stealing the city’s precious resources. When they try to report the thefts, however, they are surprised to learn that the mayor has ordered their arrest for “spreading vicious rumours.” Lina grabs Poppy and, with Doon, the three flee the city. They embark on the underground river in a boat. On the boat, they find several strange items: “paddles,” “candles,” and “matches.”
After some time, the river winds up to a rocky slope. On the banks, Poppy discovers an old book that turns out to be a journal. Lina saves it to read later, and all three make a difficult climb over and out of the rocks. When they surface, they are amazed to discover the real, natural world, especially sun-, moon-, and starlight.
From the journal, Doon and Lina learn of the history of Ember. When constructed, the founders sent one hundred adults and one hundred children there to live to ensure survival of the species. Talking about their history and exploring a nearby cave, the friends are astonished to see the City of Ember below them. Until that moment, they had not known they had been living underground.
Knowing they can never return but wanting to save others, Lina and Doon write a note with instructions for escape. They wrap the note up in Doon’s shirt and launch it over the cliff and down into Ember. Their friend Mrs. Munro discovers the package as it lands at her feet. She takes the instructions seriously and helps save the city.