The Way Between the Worlds — Ian Irvine

In the conclusion to this series, Karan, the young Sensitive who holds the Mirror of Aachen, which has the power to heal or permanently destroy the rift between Worlds, is held captive. Her lover, Llian, is in chains, falsely accused of betraying her. With the dark moon rising, the Charon Rulke is unstoppable as he prepares to open the Way between the Worlds.