Violet Abyss — Suzanne M. Sabol

Vampire politics are the worst! 

Stuck in a city she doesn't know and surrounded by enemies, Dahlia Sabin is thrust into the middle of a vampire conclave. Every Vampire Liege from across the country has descended upon New Orleans for what everyone knows is a trap. 
When an ancient relic of power turns up missing and a high-ranking vampire is murdered, Dahlia is forced into a world of vampire power plays and dark magics in order to save her friend. 

Dahlia, Patrick, and Dean must use everything in their arsenal to turn the tide of revolution, but turning enemies into allies is more difficult and dangerous than any of them knew.