Immortal Revenge — Mary Abshire

Vengeance comes with a price.

Grief stricken Katie Dillinger is on a mission to claim revenge for the death of her lover. In a race against time to find the murderer, Katie reaches out to Riker, a man listed as her boyfriend's emergency contact. The cold-hearted man comes to Katie's aid, but she doesn't completely trust him. To keep her friends safe, she insists they leave town immediately. But her efforts come too late. A friend disappears and a clear message is left in the wake: surrender or more people will die.

Katie's world is turned upside down when she discovers Riker has vowed to protect her. She's involved in a prophecy, one which her lover had been preparing her for before his murder. All the combat training he gave her suddenly makes sense, and as Katie fights to keep her friends alive, she's forced to prioritize. Revenge now, saving mankind next.