The Calling (Immortals, Book 1)

He burst into the battle, this leather jacket billowing and his huge silver sword flashing. Amber had no idea why this windswept warrior would rescue her, but there he was fighting the same demon who'd killed her sister. Though he was a stranger, she immediately sensed he'd come to protect her. And with the first touch of his lips on hers, she knew he was bound to her, his body meant for her. Yet the shadow of evil is spreading quickly, and more death will follow unless they can discover the secrets of... the calling.