The People of Sparks (by Jeanne DuPrau)

Having emerged from hundreds of years in an underground city, the 400 survivors of Ember can't go back, but have no idea how to survive on the surface. Wandering for days, exhausted and hungry, they come across the village of Sparks. The people of this small village reluctantly agree to take in the refugees temporarily, just long enough to teach them to survive on their own.

But food is tight, the Emberites don't seem to know anything, and the villagers soon begin to resent having to take care of them. As tensions mount a mysterious series of acts of vandalism heightens the anger on both sides, until conflict seems inevitable.

The first book, The City of Ember, was a fun but unexceptional story -- underground city is failing, children have to find a way out before it's too late. This sequel goes in a more thought-provoking direction. It traces, in a clear and reasonably believable fashion, the steps that lead otherwise decent people to war and, more simplistically, what decent people can do to stop it. It helps kids to begin to fathom some of what is going on in the world today.

Again it is the unassuming Lina and Doon who find the way, though both are initially led astray. But they share a common impulse to care for others, which propels them to find and take the difficult steps necessary to avert conflict. Unlike so many fantasies, this is not about good versus evil, but rather thoughtfulness and compassion versus unreasoning hate. And, as the author makes very clear, love takes a lot more strength and bravery than anger.