A young man is found decapitated in the woods and the CSIs believe the killing was ritualistic. Hodges finds the victim, Michael Wilson, has residue from a recent body wax and the team traces the wax to a hotel on the strip. Wilson was staying at the hotel and when the CSIs search his room they discover he was in town for his wedding which is taking place today. Langston, Catherine and Nick go to the hotel chapel to notify the wedding party of the victim's death but they receive a shock of their own when they find a room full of real-life vampires. Wilson and his fiancee Julie were practicing vampires who wanted to get married at the annual vampire and werewolf convention; where they met a year before. Vampires and werewolves are mortal enemies and when wolf hair is found in the victim's mouth the team traces it to the deceased pet of a practicing werewolf, Kurt Francis. DNA found on a yellow contact lens in the victim's hotel room is also linked to Francis. His truck is examined and the CSIs find not only the victim's blood but digestive enzymes from someone suffering from porphyria, also known as "vampire's disease". It turns out, Wilson held a secret - he was a werewolf. Wilson originally belonged to Francis' werewolf pack but when he saw Julie at the convention, he instantly fell in love and changed who he was for her. Francis recognized Wilson dressed as a vampire and confronted him. Francis also told a fellow vampire, Thomas Stewart, and both decided to work together to kill him. Thomas managed to also convince Wilson's fiancee Julie that he betrayed her and she was the one that delivered the first deadly blow.