While celebrating the capture of Gilroy Foster's murderer, Fiona receives a disturbing call about a ritualistic homicide in Dracul's Den, the abyss of a cave and sanctuary of a teenage vampire cult. Fiona takes on a whirlwind investigation where inconsistent leads and hardships emerge, making the case almost impossible. She is forced to confront yet another obstacle under constant surveillance by federal agents, as she is hunted by a crazed escaped convict, bloodthirsty for revenge on her father, the district attorney. Conflict, betrayal, and forbidden love flourish as Fiona realizes that her forensic training program is more like reality than she ever imagined it could be.