Two castmembers from the original Buffy the Vampire series will be joining the Winchester brothers on a very special Supernatural, delightfully titled ""Shut Up, Dr. Phil."

Cordelia Chase (Charisma Carpenter) and Spike (James Marsters) will reunite on the small screen for one episode of Supernatural! But this time around, Cordelia is the one suffering from supernatural nightmares. Her character is a scorned witch who's out for vengeance on her good-for-nothing husband, played by Marsters.

The special episode will air around Halloween.