La Muerta: Nemesis (La Muerta #11)

When an innocent child witnesses her mother's brutal killing, Maria Diaz can promise only one thing - vengeance! But this is no simple murder. Maria must again become the street vigilante La Muerta and track the killer to New Orleans. There, she is plunged into a shadowy world of secrets and sacrificial bloodshed, which leads her on a collision course with Madame Midnight, the hoodoo princess of New Orleans!