Charisma Carpenter and James Marsters are featured in this clip from Supernatural. The former Buffy the Vampire Slayer co-stars go at it on "Shut Up, Dr. Phil."
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Charisma Carpenter and James Marsters guest star on this episode of Supernatural, as teased here. Yes, it's a Buffy the Vampire Slayer reunion!
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Supernatural Season 7 Episode 5 Quotes

Dean: While you were out being Lance Armstrong...
Sam: That would be biking.

Sam: Really? From a freaking flask? What are you Bad Santa? On the job?
Dean: We're always on the job.