The Dark - Dark Sorcery, #6

Jake Macgregor, San Francisco's head of the Paranormal Special Forces Unit, has his hands full. He and his team face a powerful enemy threatening to bring down the City by the Bay. With the weight of the world already resting on his broad shoulders, and after a long, hard day's fight against evil, the last thing he has time for is romance. So why do dreams of Cassia fill his nights? Cassia is a witch with an extraordinary birthright giving her power and honor beyond any being's imagination.
It also forbids the one thing Cassia wants the most, the love of the mortal Jake Macgregor. When she intervenes to save his life, the consequences are inescapable-even though the magic they make together is too potent to resist.