Nikkita Sampson, a demon forced to live as a human until she corrects the universal imbalance she has caused, takes on the role of a serial killer dubbed by the FBI as 'the Quantico Killer.' Her demonic powers have become limited, but she still manages to maneuver about in a semi-demon form when it is necessary for her to kill and to feed. The only way for her to safely leave the human realm behind is to destroy all of those who know what she truly is and who are in constant attempts to open a portal between their two worlds. The only problem is that this secret society is of unknown whereabouts and identities. Nikkita wriggles her way into a position with the FBI under a false identity with the help of a human acquaintance who knows her story. After securing said position, she takes no time in brutally killing and feasting upon the man. She plans to use her new 'career' to try and learn more about her original human captors and do away with them, but things rarely go as planned...