Pilgrimage of the Faerie (Book Three)

Seething with vengeance cultivated over two thousand years of captivity, Lord Caelwas breaks from his Faerie-mandated prison and enslaves a sect of humanity and inflames them onto a course of destruction.
So begins Pilgrimage of the Faerie.
Through immense travail, the young but now burdened Baytel, Druid of the Citadel, only gradually becomes aware of this powerful evil now at loose. With word that his love Tira and her friend-in-battle Delphinade are imprisoned in darkness, Druid Baytel is torn between love, and loyalty to the Citadel.
As cross-currents of missions verge on failure, suspicion undermines devotion, and conflicting loyalties emerge, Baytel's battle-tested Companions unite in response, realizing they must employ all of their intelligence, courage, good humor and loyalty to face forces they do not yet comprehend.
And the land itself rumbles ominously.
What happened to the Tree Faeries?
And where is Baytel?