The Book Witch by Lyra Grey

A cursed book. An ancient coven. And a reluctant witch caught in the middle.
When thief-for-hire Evelyn steals a book drenched in dangerous dark magic, she realizes keeping it out of the wrong hands could be very bad for her health. Trouble is, a book this powerful attracts a lot of attention, so she races to get the book out of town before she gets noticed. But when the world’s oldest and most powerful coven becomes aware of its existence—and hers—she quickly finds herself long on problems and short on options.

With Valen—her client’s oversized head of security—by her side, she descends into the Dark City, a magically-sustained underworld beneath New Orleans where strange creatures roam, mad kings rule, and hell is very, very real. Faced with dangers beyond anything she’s ever seen before, Evelyn must survive and evade capture long enough to escape with the book before it’s too late.