Nick interviews a vampire enthusiast on the episode "Blood Moon." Violence has erupted at a convention during the installment.
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Problems at a vampire convention are at the center of the CSI episode titled "Blood Moon." Good luck solving that one, team!
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It's pretty clear what's going on here: Detective Vartann and Catherine heat things up on the episode "Blood Moon."
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CSI Season 11 Episode 3 Quotes

Nick: Triple homicide at the Tangers.
Ray: Let's go hunt some monsters.

Sara: Did you know a twelve letter word for "across the woods" is "Transylvania?"
Nick: Grissom? Is that you?
Sara: Shut up.