Haunted - Jeanne C. Stein

Anna Strong—kick-ass bounty hunter and vampire—has made some enemies in her time. But it's not just her old foes she should be worried about in this novel in Jeanne C. Stein's national bestselling series.
Anna's shape-shifting friend Culebra finally opens up to her about his life before he owned Beso de la Muerte, a bar catering to supernatural clientele. As if summoned by the conversation, Culebra's past stumbles into his bar in the form of an old buddy cashing in a favor.
Soon Anna, Culebra and her ex, DEA agent Max, find themselves deep in Mexico, dealing with drug cartel infighting, old vendettas and missing girls. Mexico just may prove to be Anna's best match yet...