The Shadow Road — K.V. Johansen

In Book Four of the popular Warlocks of Talverdin series, the struggle passes on to the next generation. Betrayed by a member of his own family, abducted, poisoned and forced to recreate an ancient spell that might--if it doesn't kill him--open the lost shadow road, Nethin, son of a Nightwalker lord and a human witch, is thrown into a struggle for survival in a dying land. In that land, the Homeland, he meets Alabeth, an orphan who survived the slaughter of the last warlocks by their own kinsfolk. She is willing to trust him, but her people have rejected her. Capture means execution for both, but an even deadlier foe plans vengeance against Nethin, and the life of every Nightwalker rests on what Nethin does next.