Dead of Night by Kali Argent

Heir to a throne he never wanted, vampire prince Nikolai Diavolos has seen firsthand how power corrupts. Abandoned by his siblings and betrayed by his father, he doesn’t have much use for family—until the Revenant offers him a second chance. Now, he’ll do whatever it takes to prove his worth, even walk through the fires of hell to face the most powerful coven in the country.
Held for months by the Abraxas Coven, Kamara Yamashito is beginning to lose her grip on reality. Nothing seems real anymore. Nothing feels right. She’s hearing things, a stranger’s voice in the back of her mind, a voice that promises salvation, but Kamara knows the truth.

No one can help her.

Nikolai never expected to survive the mission, let alone find his mate within the walls of the compound. Fierce, brave, and resilient, Kamara is everything he’s ever wanted, but freeing her from the coven is only the beginning.
The real fight will be finding a way to save her from herself.