Gildart Jackson is set to go back in time on Supernatural.

The actor - currently hosting Whodunnit? on ABC - will appear on Episode 4 of Season 9 as a veteran member of The Men of Letters, according to The Hollywood Reporter.

Jackson is currently only booked for installment titled "Slumber Party" and will be featured in a flashback.

Supernatural Season 9 kicks off on October 9 and Battlestar Galactica alum Tahmoh Penikett was recently announced as a premiere guest star.

He will portray a fallen angel on the season opener.

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