A young woman and amateur photographer is brutally murdered in the park and a part of her ear is bitten off. Mac and the team investigate why someone wanted to kill her in this way and find out that the victim is a member of a unique type of cult, she is a Sanguine vampire. A small scar on her wrist, which occurred during an initiation ceremony where the leader of the cult draws blood from the new member and drinks it, is also seen by Mac on her father's wrist. Mac presses her father and he admits that he lead his daughter into this "religion." The team begins to suspect the leader of the cult may have killed the victim and when they search his home they find the murder weapon, an Ankh - the same tool used in the initiation ceremony, and the piece of her missing ear. While it seems open and shut, the victim's photos in the end help investigators find her real killer - her boyfriend. He was disgusted by this "religion" and the idea that his girlfriend would enjoy this lifestyle. In a rage, he followed her to the park where she normally enjoys taking photographs and violently murders her and attempts to frame the man he blamed for encouraging this way of life; the cult leader.