Lassiter is having a drink after work at a bar when he meets a woman named Marlowe, whom he is instantly attracted to. They hit it off immediately. After Lassiter tells her he is a cop, she asks to be excused to use the restroom. Several minutes pass by, and Lassiter thinks he has been stood up. Several minutes pass, and Lassiter checks the ladies restroom to see if Marlowe is okay. He doesn't find her. She has disappeared, and Lassiter is devastated.
The next morning, Lassiter arrives at a crime scene where a dead body was found. He gives special orders to McNab to find his mystery woman, Marlowe. They go to examine the body, and Shawn SV's puncture wounds on the man's jugular and wrist. Then Lassiter is devastated by the next clue he sees on the body: The same exact Eternal Life Symbol Necklace Marlowe was wearing at the bar. The woman he is infatuated with could be the person that murdered this guy. Upon seeing the puncture wounds on the victims wrist and neck, Shawn makes a bold proclamation that the killer was a vampire. And in a stunning turn of events, Lassiter jumps on board with Shawn's crazy theory and boldly agrees.
At the coroner Woody's office, Shawn, Gus, Lassiter and Juliet are told the body was drained of almost all its blood, thus causing the guys to further believe in their vampire theory. Juliet is the only person who isn't buying it.
Lassiter breaks off from Juliet. He heads to the Jewelry store where the Eternal Life necklace was likely purchased and questions the store clerk. The store clerk says those necklaces are very popular and does not have a record of who would have purchased it. The clerk admires Lassiter's watch, causing Lassiter to take a closer look at it. In doing so, he sees a single fingerprint — Marlowe's fingerprint!
Juliet, Shawn and Gus head to a vampire bar to get the skinny on who would be needing large amounts of blood. They meet a bartender who tells them that he got a strange call from someone asking where they could get their hands on a pint of blood. They trace the number and are lead to an address...
Meanwhile, Lassiter has found Marlowe and has successfully gotten her alibi for the night of the murder. Also, Lassiter sees that she is wearing her Eternal Life necklace, letting him know that it wasn't the same necklace that was found in the victim's hand.