Blood Catalyst. Here Witchy Witchy, #8

Death threats, black magic, and vampire business is all just another day in the life of Abigail Collins. Abigail has her hands full with her first PIB case since she came back from leave. When the brother of a Cult member shows up dead, Liz requests Abby be put on the case. The cause of death? A missing heart. The case leads her to the local Coven, and she must find the culprit before the Cult grows impatient and takes things into their own hands.
And if that wasn't enough, a second case is dropped onto her plate. Agent Yorkingson calls Abby in to consult on a King of Vampire's case hoping that her magical skills will come in handy. When the clues all point to Ira succeeding in creating the perfect hybrid, things go wrong, very wrong.