This promising debut is set in a dying underground city. Ember, which was founded and stocked with supplies centuries ago by “The Builders,” is now desperately short of food, clothes, and electricity to keep the town illuminated. Lina and Doon find long-hidden, undecipherable instructions that send them on a perilous mission to find what they believe must exist: an exit door from their disintegrating town. In the process, they uncover secret governmental corruption and a route to the world above. Well-paced, this contains a satisfying mystery, a breathtaking escape over rooftops in darkness, a harrowing journey into the unknown and cryptic messages for readers to decipher. The setting is well-realized with the constraints of life in the city intriguingly detailed. The likable protagonists are not only courageous but also believably flawed by human pride, their weaknesses often complementing each other in interesting ways. The cliffhanger ending will leave readers clamoring for the next installment. (Fiction. 9-13)