This book is about a city called Ember, where the sky is always black. The only light comes from the city's great floodlights, which tower over the streets. But supplies are running out in Ember. There have been shortages of everything, especially lightbulbs. People are afraid that they will soon have to live in the darkness.
Lina Mayfleet is a twelve year-old who lives with her grandmother and little sister, Poppy. At the age of twelve, everyone is assigned to a job in Ember. She ends up being a messenger for the city. One day, she comes home from her job and sees Poppy chewingon a piece of paper. She retrieves the paper from her sister's sticky fingers and looks over it. What letters that are left on the paper after Poppy toreit up are perfect, not handwritten. They're just like the letters written on the cans that Ember's food comes in.
Doon Harrow lives with his father. He's the same age as Lina, and a Pipeworks laboror for the city of Ember. He knows Lina pretty well, and one day she decides to show him the paper. Together, they decipher the missing words and eventually learn that the paper contains instructions on how to get out of Ember, to a place where the sky is blue.
The rest of the story follows their quest to escape from the city, which they finally achieve through tedious work. Once they are out of Ember, they realize that they had been underground the whole time! They rest for a few days, then go searching. Eventally, they find a very deep hole and decide to climb into it. From inside the small cavern, they can see the dim ights of Ember in the distance. Lina makes a sling out of some cloth and a rock and puts a copy of the instructions in it. Doon sends it sailing toward the faraway glow, where one of Ember's residents finds it, and leads the citizens of the city abive ground, to start a new life.
