Black Hat, White Witch by Hailey Edwards

Remember that old line about how the only way out of the organization is in a pine box?

Well, Rue Hollis spent ten years thinking she had escaped the Black Hat Bureau, no coffin required.

Then her former partner had to go and shatter the illusion by showing up on her doorstep with grim tidings. As much as Rue wants to kick him to the curb, she agrees to hear him out for old times’ sake, and what he says chills her to the bone.

The Silver Stag was the most notorious paranormal serial killer in modern history, and Rue brought him down. Now a copycat has picked up where the Stag left off, and the Bureau wants her on the case. She beat the Stag once. They think she can do it again. But they don’t know she’s given up black magic, and she’s not about to tell them. White witches are prey, and Rue is the hunter, not the hunted. Always.

But can she take down the protégé of the man who almost beat her at her black witch best?

If she wants to keep her new town, her new home, her new life, then she has no choice but to find out.