The Tower on the Rift (The View from the Mirror Quartet)

In this second volume, Karan, a young Sensitive carrying the blood of all three Worlds, comes into possession of the Mirror of Aachen, which holds the power to heal--or destroy--World relations. But as war rages, Tensor, the leader of the Aachim people, steals the mirror and flees with the young chronicler, Lilan, leaving all to wonder how they plan to use this magic.