S3, E7: Sam and Dean capture a female vampire named Lucy (Mercedes McNab - "Buffy the Vampire Slayer") who claims to have no knowledge of how she became a vampire. The guys discover that Dixon (Matthew Humphreys), a male vampire, is feeding human blood to unsuspecting females in bars, telling them it is the “latest drug” and turning them all into vampires. Meanwhile, fellow demon hunter Gordon Walker (recurring guest star Sterling K. Brown - "Army Wives") escapes from jail and goes after Sam -- and after being intercepted and turned into a vampire by Dixon, Gordon's a much more formidable adversary."