It's time to focus on the Mark of Cain and the Book of the Damned.

And according to these preview pictures from Supernatural Season 10 Episode 21, Castiel, Charlie and Rowena are teaming up. This is not going to go well...

I wouldn't be surprised if Castiel has to play referee to Charlie and Rowena. Or maybe it'll be like an episode of Three's Company. There will definitely be some great quips between all of them.

Good luck, Castiel. That's for sure.

Supernatural Photos From "Dark Dynasty"

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We also get a brief photo glimpse of Sam and Dean having a serious conversation. Has Sam finally told Dean about what he's been up to with the Book of the Damned?

Probably not, but they are definitely focused on whatever case of the week is taking place. Let's hope they can get the job done as a team!

Take a peak at these fun photos from "Dark Dynasty," and then check back for my recap and review after the episode airs on Wednesday at 9/8c.

And catch up on all the episodes when you watch Supernatural online right here at TV Fanatic!

Sean McKenna was a TV Fanatic Staff Writer. He retired in May of 2017. Follow him on Twitter.