As Sam and Dean Winchester still contend with unleashed evil souls from Hell roaming free on Earth, they reunite with an old ally in the final season of Supernatural: Rowena.

The CW has released official stills from an upcoming episode in the final season, aptly titled "Raising Hell," showing Ruth Connell reprising her role as the fan-favorite witch to summon Ketch to help deal with the apocalypse, with Francis Tumblety and Kevin Tran caught up in the action. The photos and official episode synopsis are below.

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SENDING OUT AN SOS -- Sam (Jared Padalecki), Dean (Jensen Ackles) and Castiel (Misha Collins) call on Rowena (Guest Star Ruth Connell) to help keep the evil souls at bay and get an unexpected assist from Ketch (Guest Star David Haydn-Jones). Robert Singer directed the episode written by Brad Buckner & Eugenie Ross-Leming (#1503). Original airdate 10/17/2019.

Debuting in Season 10 as a major antagonist, Rowena gradually became an ally to the Winchester Brothers and Castiel over the course of the series, using her vast knowledge of magic to combat evil. With hellish forces unleashed on Earth, Rowena may be the key to saving all of existence from the apocalypse.

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Returning Thursday, Oct. 10 at 8 p.m. ET/PT on The CW for its final season, Supernatural stars Jensen Ackles, Jared Padalecki, Misha Collins, and Alexander Calvert.