The People of Sparks, Jeanne DuPrau Yearling, c2004 338 pages.

This book continues the story of Lina and Doon as they lead the people of Ember to safety.
Escaping from their underground world they find the small city of Sparks. At first the people of Sparks are willing to help the refugees but soon differences between the two groups grow.
This is an interesting story of the way Lina and Doon help resolve the conflicts that arise.
The characters are round and develope throughout the story. The plot is interesting and holds your attention to the end.