Against the Empire — Jeffrey Quyle

The fifth book of the Ingenairii Series provides a dramatic change in location as Alec journeys on a desparate solo adventure to regain the powers he has lost. When his journey takes him to John Mark's lost cave, Alec finds himself transported to a new part of the world, one unknown to the Dominion, where a strange and dangerous culture exposes him to a demonic menace that he cannot defeat. With a new friend to guide him through the puzzling ways of Michian, Alec must find a way to remove the threat that Michian poses to the Dominion, and to his own life.