Sleeping With Shadows by Rachel Hailey

When Ash stepped into her office, Callie never thought the Fae who nabbed her heart held a secret darker than his soul!

Once The King of Nightmares, Ashe lost everything when he was betrayed. Released from prison, he’s got one goal: Stay Free. To make that happen he’ll have to rescue the girl who stole his crown while saving the court he’d rather see burn. But he can’t do it alone. He needs Callie.
Abused, neglected, and finally shunned by The Court of Light, Callie is done with court politics. It’s just too damned bad Ashe doesn’t care. He’s arrogant, manipulative, and dangerous. Everything she’s been taught to fear. It would be so easy to hate him, but the sadness in his gaze calls to her heart, and his touch awakens her own darkness. She has never wanted anyone more.
Callie is Ashe’s darkest desire, but to earn his freedom and prevent the destruction of humanity, she must embrace the destiny that will keep them apart. But is the safety of the world worth losing the kind of love he’s only dreamed of?