The Restorer's Son — Sharon Hinck

Chosen to save a people. Called to serve an enemy.
 
Plunged again into the gray world of Lyric and Hazor, Susan and Mark search frantically for their teenage son, Jake, as all signs hint that a trusted ally has betrayed them. Assassins, political intrigue, false leads, and near misses beset their path, which will lead them into the dark prisons of Hazor before the One's purpose is revealed. 

Cast out by those he trusts and preferring to cross swords with the One rather than yield to His will, Kieran flees to enemy Hazor, only to find that the One knows no borders. Pursued by his calling, Kieran finds a boy without a home, a king with burning questions, and a nation torn by darkness. As he embraces the tasks the One has set before him, this new Restorer learns that the One requires his all -- perhaps even his life.