The People of Sparks by Jeanne Duprau -- 352 pages
The people of Ember have never experienced things like weather and animals, and they have never lived without electricity, which to the people of Sparks, is an ancient invention that no one can understand anymore.
But the people of Sparks, though they started out friendly enough, are becoming less and less hospitable, and when vandalism breaks out, it looks like the people of Ember are being framed.
Lina and Doon are on the case to discover who the guilty party is, and how Ember is going to survive the winter.
Like The City of Ember, this book is engaging and intriguing for all ages. It makes an impressive sequel.