Valley of Silence (The Circle Trilogy Book 3) by Nora Roberts, Jove Books, 2006.
#1 New York Times bestselling author Nora Roberts presents the electrifying conclusion to her powerful Circle Trilogy. Worlds have collided and centuries have elapsed as six people have brought their unique powers, their courage, and their hearts to a battle that could drown humanity in darkness… Her face, so pale when she’d removed her cloak, had bloomed when her hand had taken the sword. Her eyes, so heavy, so somber, had gone as brilliant as the blade. And had simply sliced through him, keen as a sword, when they’d met his… In the kingdom of Geall, the scholarly Moira has taken up the sword of her people. Now, as queen, she must prepare her subjects for the greatest battle they will ever fight—against an enemy more vicious than any they have seen. For Lilith, the most powerful vampire in the world, has followed the circle of six through time to Geall. Moira also has a personal score to settle. Vampires killed her mother—and now, she is ready to exact her revenge. But there is one vampire to whom she would trust her soul… Cian was changed by Lilith centuries ago. But now, he stands with the circle. Without hesitation, he will kill others of his kind—and has earned the respect of sorcerer, witch, warrior, and shape-shifter. But he wants more than respect from Moira—even though his desire for her makes him vulnerable. For how can a man with an eternity to live love a woman whose life is sure to end—if not by Lilith’s hand, then by the curse of time?Don’t miss the other books in the Circle Trilogy Morrigan’s Cross Dance of the Gods