Ash had promised himself into servitude to a demon when he was only a child. He spent his life killing for the demon, and he was good at his job. It was the only way to ensure the safety of his sister. When a brush with death brings Dr. Elizabeth Rone into his life, things change. The demon wants her dead, and for Ash, that's a deal breaker. He never killed an innocent soul. Not only was she innocent, but she made him feel things he had thought he was incapable of. With a demon hell-bent on her demise, will Ash be her savior, or will she be the one saving him?