Supernatural will be saying hello to an old familiar face before season 9 come to a close.

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With Sheriff Jody Mills (Kim Rhodes) set to appear in "Alex Annie Alexis Ann" (episode 19), another minor character will be popping up in episode 21.

"Exciting stuff N this episode! Minor, obscure character returns," tweeted S. E. Hinton, Supernatural fan and author of The Outsiders, while visiting the Vancouver set on Wednesday. "No, not Gab[riel], Bobby, or Balthazar. MINOR. Very surprised Major Happening."

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Titled "King of the Damned," the episode will also feature Castiel (Misha Collins), Crowley (Mark Sheppard), Abaddon (Alaina Huffman), and a new character.

"New actor this week. Don't know if he will be back--but he WILL be a fan favorite! Calling it now!" Hinton tweeted on Friday, adding that the audience "will never expect who this guy is. He doesn't interfere with anyone's story line."

Billed as a fairly serious episode, "King of the Damned" will air during the season 9 homestretch and will hopefully continue to help coalesce the year's major story lines. While it does not look as if Metatron (Curtis Armstrong) will be popping by, Castiel should be handling the angel end of the Winchester's problems while Crowley and Abaddon will be there to take care of the demon front.

Supernatural airs Tuesdays at 9 p.m. ET on The CW. Click the video below to see a preview for the series' next episode, "Meta Fiction."