Dexter is a show obsessed with blood. So maybe fans shouldn't have been so surprised -- to say nothing of shocked, baffled, and repulsed -- by the so-called incest storyline between siblings Dexter and Deborah Morgan this season.

The pair aren't blood relatives, after all: Show runner Scott Buck tells TheWrap that writers have considered the possibility that Deb (Jennifer Carpenter) might carry romantic feelings for Dexter (Michael C. Hall) almost since the start of the show, even though it took her until Sunday's season six finale to truly realize it. (Carpenter and Hall must have seen the possibilities; they were briefly married during the show's run.)

It's an idea that has been talked about in the writer's room, I think, from at least season two, Buck said Monday. It just felt like those kind of feelings were very integral to the character of Deborah, that she was in love with her brother without even realizing it. It's something we'd always talked about and it just felt like it was time to finally deal with that issue.

He added: It's funny to me that people could happily accept Dexter as a serial killer, but once Deborah has love for her brother, that that's where the 'ick' factor for them comes in.

It's not like television hasn't gone there before: Relations between non-biological siblings would be positively tame compared to the blood-relative incest in the latest seasons of Boardwalk Empire and Game of Thrones.

Deb's love for Dexter complicates the other major development of Sunday's finale: She finally caught him killing someone (the Doomsday Killer, played by Colin Hanks). Fans and even Carpenter have long said it strains believability that Deb, a brilliant homicide detective, wouldn't figure Dexter out. Now that she has, her love for him makes the dilemma of what to do about it even more complex.

We talked to Buck about his plans for the show's remaining two seasons -- and how much of a say Hall, also an executive producer on the show, will have in the fate of his character.

TheWrap: You're the third Dexter show runner in as many seasons. Do you think you'll stay on the job through the show's run?

Buck: I certainly hope so. It's not necessarily in my hands but I like to think I'll be sticking around. ... The previous show runner to me was Chip Johannessen, who moved on to Homeland, and prior to that was Clyde Phillips, who was with the show from the beginning. And Clyde lives on the East Coast. For him it was just time to get back close to the family, really.

There's kind of a Rocky movie question with Dexter -- people around him are always dying, and you wonder how much more you can raise the stakes after his wife's murder in the fourth season. His son was in danger in the latest finale -- is Deb in added danger now?

Buck: I think everyone's always in danger on this show. But we're fond of Deb so it's unlikely that we would ever take a knife to her.

Whether Deb will find out Dexter is a killer has been a major source of tension for the whole series. How big of a leap was it to commit to her finding out, with two seasons still to come?

Buck: It was a big leap, but with a show that's already been going on for five years, it felt like it was time to finally address that. You don't want to have all your big, exciting reveals in your final season or your final few episodes. We'll deal with this in a fun, dramatic way. It just felt a little dishonest that Deb was not finding out after all this time. So it was time to finally let her pull the curtain back, at least a little bit, and see who Dexter is.

This has always been a show not about plot twists and turns and action scenes, but more about the character of Dexter, this very unique character that we've never seen anything like before. It's a character that's gradually evolved over the last five years and will continue to change. There's a big creative team behind the show, a number of different writers and producers, and certainly Michael Hall has a huge voice in what happens with Dexter, so it's eventually going to come to a point where we're all going to sit down and compare notes on this.

I think fans always want the sense that you had a grand plan from the beginning, and if we'd only paid attention we would have seen it all --

As far as where we end? Absolutely. I know exactly where I want it to end. But that's where Michael Hall wants it to end, we'll have to see if we're thinking along the exact same lines. Even though I'm going to be interested in what everyone has to say or everyone has to think, it's ultimately going to be one voice that decides where the show goes.