Out of the Shadows - Clann na Morrigna, #1

Never piss off a daughter of the Morrigan, especially in a town like Nightshade. Nightshade's a weird town. It has a large Pagan population and a lot of fundamentalist Christians. Usually, they get along well. Then the attacks started. It began with assaults. A Christian had satanic imagery burned into her. A Pagan had a cross pounded into him. Assaults became rapes, then murders. Each side blames the other.
Detective Tiernan Dempsey turns to two of his friends for help, Dr. Alexis O'Connor, anthropologist and Wiccan priestess and Honor MacGregor, Pagan PI. This case forces Honor to face fears she thought buried leaving her with severe trust issues and a touch of paranoia. Then she set eyes on Ethan Malone. Ethan expected his life to be unending darkness. Wounded by his past, he resolved to never suffer that pain again.
As long as he didn't let anyone get close to him, he had nothing to fear. Then he set eyes on Honor MacGregor. And the body count continues to climb. Then reports of possession emerge.