Seeker — William Nicholson

When his brother is exiled from the Nomana without any explanation, sixteen-year-old Seeker sets off on a journey to rescue him--and to find out what really happened. Along the way, he meets two other young people who are on quests of their own, and in a shocking turn of events, the three are soon caught up in a harrowing and bloody race to save the Nomana--and themselves--from destruction.