Jeanne DuPrau

In the city of Ember, the sky was always dark. The only light came from great floodlamps mounted on the buildings and at the tops of poles in the middle of the larger squares. When the lights were on, they cast a yellowish glow over the streets; people walking by threw long shadows that shortened and then stretched out again. When the lights were off, as they were between nine at night and six in the morning, the city was so dark that people might as well have been wearing blindfolds.