'Supernatural' Showrunner Jeremy Carver Prepares for Finale, Spinoff

The Mark of Cain has turned Dean into something of a cold-blooded killer, and his contact with the First Blade has made the tension between Sam and Dean almost unbearable. But isn't that always the way with family?

Yahoo TV got a chance to talk with Jeremy Carver, a former writer for "Supernatural" who left to co-create the American version of "Being Human" on Syfy before returning as the showrunner last season. Currently The CW is filming a backdoor pilot for "Supernatural: Bloodlines," which will air as the 20th episode of the season on April 29. Carver talked about family, how real life creeps into fantasy, and learning that even monsters have feelings.

Are you introducing any more major story lines headed into the last few episodes of the season or are you just building to the finale now?
Well, there's a couple of things we'll be building on that you [saw] this week: Dean coming into the vicinity of the First Blade, what happens with the First Blade and the Mark of Cain. You'll see a couple little things start to crop up here and there. But yeah, at a certain point we'll be driving towards the conclusion.

Do you have plans for Season 10 already?
We have a beautiful minelike room full of yarn, thumbtacks, and Enochian symbols all mapping out Season 10. [Laughs.] No, we have ideas, but we don't have — we have this arc that we've been putting our characters on, this sort of larger mythology arc that we hinted at last season, but in terms of the nuts-and-bolts specifics, those are still to be worked out.

Did the season renewal change your storylines in any way, knowing that you'd definitely have that room?
Knowing that we had a Season 10 allowed us to rewrite the end where Sam and Dean are holding hands and going off the cliff in the Impala. We can hold off on that one for now, but other than that it's pretty much all systems go.

Will the angels-trapped-on-Earth story resolve this season or continue into the next?
I think all of that really plays into our climax in Season 9.

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You've said in the past that you go where the story takes you. Where have you gone that you didn't expect to go when you became the showrunner last season?
Well, I guess, starting with Dean's relationship with Benny the vampire last year — the idea that good and evil could potentially find a way to be friends? And blurring the lines — it's a gray world, not so black and white.

But that has even stretched into this year with Crowley and his addiction to human blood. And just seeing different shades of characters, now we see a different side. That's something that all of us here have been excited about. Taking these characters that we and the audience thought we knew and really shedding a whole new light on them.

Another thing would be that the brothers seem to always have something more hurtful to say to each other than you ever thought could be said. And that's only being half facetious. I can only say that the longer you stay on the show, the more that you feel like it's a real relationship. And they're really family and they really know how to love each other and really know how to get under each other's skin. Which is basically like me and my older sisters. The more we can keep it true to life, the more the people find it relatable.

Are there any other experiences from real life that you've brought into the show?
No — well, I won't speak for myself, but I will speak for the writers in general. I think the fans would be surprised to know just how much real-life experience comes into even a genre show like this. The writers have really, really found ways to sprinkle in past experiences. Really, past emotional experiences, things that really meant a lot to them in their lives and have grafted their experiences into this world, really seamlessly.

One day, there'll have to be a writers' panel where they can all sit around and say, "Oh yeah, that was me as a kid." "Oh yeah, that was me with my first kiss." Pretty remarkable, actually, the amount of true-life stuff that's in there.

How involved are you with the "Bloodlines" spinoff?
Pretty involved — we're shooting it right now. They're out there shooting and I'm working on the finale for the mothership right now while they're shooting the spinoff.

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Are you doing things there that you haven't been able to do on "Supernatural"?

Well, it's a different beast by design of those of us who have been working on the spinoff from the beginning. It's intended to be of the "Supernatural" world, but something a little bit different from the "Supernatural" mothership, as it were. Just the whole construct of the thing. It's really cool and really great, and it's a challenge because it is different than the show we're doing now, which is why I think folks will really embrace it.

Was there anything you learned from your time running "Being Human" that you brought back with you or that you'd like to pass on to the "Bloodlines" showrunner?
I think — and this goes back to something you asked me earlier in the conversation — I think by doing a show about monsters, basically a show about monsters with feelings, when I came back to "Supernatural" I looked at it through the lens of, well, I guess monsters do have feelings. That definitely had an influence on some of the Season 8 stuff. Again, go back to the character of Benny. And in terms of showrunning the spinoff: time management — that's it. The secret to success, there it is. No no, I think Andrew Dabb, who's written the spinoff, is more than ready to jump in, and he'll do a wonderful job.

Any plans to change Castiel's costuming now that John Constantine's coming to TV?
[Laughs.] Yeah, maybe next season, Castiel will be wearing satin. Pantsuit? I don't know, we're working on it.

"Supernatural" airs Tuesdays at 9 p.m. on The CW.