People of Sparks - DuPrau, Jeanne

When the people of the underground city of Ember follow Lina and Doon to the surface, little prepares them for what they will encounter. Leaving behind the darkness that has been their home for generations, they discover a world of colour, warmth and light. The people of the small village of Sparks seem willing to help them . . . at first . . . but life on the surface has it's dark side too. Before long the villagers of Sparks become more reluctant to share their precious resources with the strange, new underground people. Lina and Doon watch in horror as the differences between the two groups grow into resentment, anger and hate. Somehow they must help overcome the distrust and bring the people of Ember and Sparks together.