When six teenage girls disappear in seven days in a small town, Dean and Sam investigate the case. They go to the house of the last girl that went missing, Kristen, and they find that the girl is a vampire fan. Sam hacks her notebook and finds that Kristen had a date with a weird guy in the Black Rose bar.
The Winchester brothers go to the place and they discover that there are many vampires there. While fighting with a strong vampire, he forces Dean to drink his blood and Dean is turned into a vampire. Samuel tells that the only chance that Dean may have to become human again is killing the vampire and using his blood to revert the transformation.
"Live Free or Twihard" is another great episode of the Sixth Season that has finally taken off. The music score of Bauhaus "Bela Lugosi Is Dead" is a great tribute to the cult "The Hunger", which is one of the best vampire movies ever. Sam's attitude toward Dean is strange and intriguing and the question is what might have happened to him? My vote is eight.
Title (Brazil): "Viva Livre ou no Crepúsculo" ("Live Free or in the Twilight")