'Supernatural' Season 10, Episode 10 Spoilers: Mid-Season Finale Episode Promo Video Teases Dean Covered In Blood And Asking Castiel For A Favor [WATCH]

The CW Network released an intense promo video for the next episode of "Supernatural" Season 10. The mid-season finale episode titled "The Things We Left Behind" will bring back Dean Winchester's (Jensen Ackles) dark side as the Mark of Cain continue to an impact on the hunter.

In "Supernatural" Season 10, episode 8 titled "Hibbing 911," Dean told his brother, Sam (Jared Padalecki), in the ending scene that he feels like himself again without the Mark of Cain pushing him. However, the promo video for the next episode showed Dean Winchester covered in blood while holding a knife.

According to a TV Line report, Dean will finally make a decision on the Mark of Cain that is still troubling him. "I need you to promise me something," Dean tells Castiel (Misha Collins) in the promo video and the angel agrees.

Dean wants Castiel to take him out if he once again turns to the dark side. "What do you mean?" Castiel asks with a confused expression on his face.

The promo video further teased a bloody Dean with his victims surrounding him with the words "Mid-Season Finale Ignites the Mark of Cain" flashing on the screen. "So you haven't changed?" Crowley (Mark Sheppard) declares before the episode trailer ended. Watch the "Supernatural 10x09 Promo 'The Things We Left Behind' (HD) Mid-Season Finale" promo video below.

The upcoming episode's synopsis in an Examiner report teased that Castiel will be able to locate his vessel Jimmy Novak's daughter, Claire (Kathryn Love Newton), in a group home. The teenager convinces Castiel to break her out of the group home but she runs away from the angel.

Castiel calls the Winchester brothers for help in finding Claire before the teenager gets in some serious trouble. As for Crowley, the King of Hell will be facing his biggest challenge yet and it could involve his witch mother, Rowena (Ruth Connell).

The previous episode did not feature the red-haired witch and her son after the shocking revelation took place in the ending scene of "Supernatural" Season 10, episode 7 titled "Girls, Girls, Girls." The mid-season finale episode titled "The Things We Left Behind" is scheduled to air on Tuesday night, Dec. 9, at 9/8c on the CW Network.

Credit: YouTube/Television Promos

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