Graham Yost and the team from "Justified" just concluded a season unlike any of the three previous ones. (My finale review is here.) Season 4 was built around a mystery, dealt more than ever before with Raylan's background as a son of Harlan, beefed up the role of several supporting characters and had several notable changes of direction as it was being made.

I talked with Yost about the Drew Thompson mystery, why we never got to see Adam Arkin reprise his role as Detroit mob boss Theo Tonin, why everybody loved "Decoy" so much, and a lot more.

My understanding is that Shelby wasn't originally Drew. Who was it originally, and when and why did that change?

Graham Yost: We started with the idea that he would be someone up in Cloverhill. It was part of our interest in class distinctions in Harlan. But we started to feel like that was expected, and we didn't have that much weight in those characters, even though we had Sam Anderson and a bunch of other great guys. So we started playing with the idea that it would be Josiah, and that made a certain amount of sense. But we knew we wanted to remove Josiah's foot, which was going to be a problem. We knew we wanted Drew to be on the run for a couple of episodes, and a man missing a foot would make that difficult. We had that in our heads. I think that we might have even kicked around the idea in the room that Shelby was Drew, and it didn't really land. And as is often the case on the show, we'll revisit things and see them in a different light. I was working on episode 5, where we go to see the hill people, and I got a call from the room, and Ben Cavell had really been thinking about it and came up with this pitch that Shelby was Drew. And we just kicked it around for a while, and tracked back what we knew About Shelby, and his age, and his story. It fit. It worked. There wasn't a lot of fancy footwork we had to do. It just fit. That just felt good to us. And Fred Golan had heard a story about a guy who was a state rep in Arizona or something, who it was discovered years into his service was a wanted felon. We liked the idea of someone who isn't hiding on the outskirts, but has actually made a life for himself.

Did you have to do any retrofitting to the episodes you had already shot, once you decided that Shelby was Drew?

Graham Yost: We did a tiny bit. In, I think episode 3, someone comes into Shelby's office, and you see that Shelby is looking at the computer at the change in the autopsy report, and that Waldo Truth was the guy who died falling out of the airplane. That was one thing we added in. And once we decided it was him, that changed how we were going to approach 6. 6 was Raylan looking for Josiah to give him his foot back, and we decided, 'Well, why not involve Shelby in that story?' And make it about the mutual suspicion between Raylan and Shelby, before they come to trust each other. But that  wasn't really a retrofit.

Was the plan always to reveal Drew's identity when you did, or was that also something that changed?

Graham Yost: That we knew fairly early on. We just knew that it would wear thin if we tried to string it out to the end of the season. The fear was that the air would go out of the balloon once we did it. But it was my feeling, and the room backed me on it, was there was enough to do after.

Given how strongly people responded to the post-reveal episodes, in hindsight do you think you could have done it any sooner? Or is this the way the season had to play out?

Graham Yost: I honestly can't think of anything more we could have done after. It felt like it was the right balance. Just the basic three-act structure of the season. That felt like a good end of the second act: the big reveal.

You said before the season that you wanted to try to do something you hadn't done before. Having now done a most-of-the-season mystery, is it something you would want to do again? Was it more challenging than you expected? Or did it work out about as you figured it would?

Graham Yost: There's sort of three questions in there. One is would we do it again? Probably not, but only because we've already done it. Because we're not in basic construct a mystery show, to do it again would feel like we were repeating ourselves. That doesn't mean we won't have mystery elements: Something happened. What happened? Who did it? And play that for a chunk of the season. But I can't imagine it being the full arc of the season. Did it work out as well as we hoped? It worked out as well or better. We had very serious concerns about it, because we were trying something that was new for us. I see the problems faced with any season-long mystery show in the serialized era that we're in. It's difficult, because you can only give so much information per episode, but you have to give enough that the audience is satisfied. Any criticisms I've heard of the season is that people felt we were off to a slow start. Which I've heard from you, and to which I say, 'Shut up! We're doing the best we can!' (laughs) No, listen, I'm proud of the first four episodes, but it really does kick in with the fifth. But I'm particularly fond of the second episode, where they go to the Truth family, and the fourth episode, which is basically about Raylan tracking down Lindsey and Randall. But I can see that. It is a problem. You look at other shows — whether it's "Twin Peaks" back in the day, or "The Killing" — that's a tough arena to toil in. I will say that. I think for people who were not hired because we were mystery writers, I think we did a pretty good job. I don't think it's great, but I think it's pretty good. And I think what makes it "Justified" is the characters, and the scenes we came up with — the funny bits and the alarming bits.

What were you expecting Adam Arkin's availability to be going into the season? Was Theo supposed to make some appearances, or did you know all along that he'd be too busy working on "The Americans"?

Graham Yost: We were expecting that we would get him maybe three times. But "The Americans" was behind the 8 ball from the beginning. They had a late pickup, a hard air date of January, which they managed to push to the last days of January. Then Hurricane Sandy hit, and that put them further behind right from the beginning. The ability of Joe Weisberg and Joel Fields and all the writers, and the production team — Adam being a big part of that — to pull off the season is pretty remarkable. What it meant was that they were just staying ahead of their schedule. I always say the writers room starts laying the track in summer and then then the train starts rolling in October, and we're frantically trying to stay ahead of the train. They were just trying to stay ahead of the train the whole time. So that meant the idea of trying to snag Adam here and there, could have been done, but I frankly didn't want to throw that at Joe and Joel. And then Adam had to fill in for a director who wasn't available. So then he did episode 9, I believe, of "The Americans," so that hampered us more. So then that became, 'Okay, well we have this expectation of seeing Tonin; what can we play with that?' Again, the mantra of the show is to deliver what people expect in an unexpected way. We've been so lucky in casting, and getting Mike O'Malley to play Nicky Augustine was a huge coup. We could tell in episode 5 that he was electric. And he had availability issues, because he's a writer on shameless. So he could really only give us a day per episode, or at most two. But by the end of the season, his writing duties were mostly finished, and so he was more available for the last few episodes.

This was a season dealing with a lot of characters and a lot of agendas, and even though you resolve the future of the Detroit mob in the finale, it's an episode that's mainly about Raylan and Boyd.

Graham Yost: That was our intent from the beginning. We liked the idea of the season being in part about the road to hell being paved with good intention. Both Boyd and Ava, and Raylan, have goals for the future, and the things that they'll do to try to secure that. Raylan's able to extricate himself in the final episode and protects Winona and the baby, and keeps his job. Boyd is only able to accomplish one. He's not able to protect Ava in the end. But he does get a promotion. We liked the idea of these guys both winning, but also losing.

One of the things that came up a lot throughout the year in Raylan's conversations with Arlo, with Hunter and with Boyd is just how much of his father he has in him, and whether he just uses the marshal's badge as a cover to do bad things. In the finale, he has the opportunity to execute Nicky and doesn't, though he also stands by and lets Sammy's guys do it.

Graham Yost: That's the central struggle in Raylan's life: how much of his father is in him, and how much of his mother is in him? It's also the split between the bad father Arlo and the good father Art, and trying to satisfy both poles. So his success in the episode, there's a real Arlo-ness to him, and yet it does satisfy the Art of it.

And is he now living in Arlo's house, or is that temporary?

Graham Yost: We haven't resolved that. We think that's a temporary thing. The disposition of the house is something we can deal with next year.

Do you have a specific plan in mind for Ava for next season, or might this become a Winona situation where Joelle only appears occasionally going forward?

Graham Yost:

We plan on seeing her a lot next season.

What's happened to Johnny?

Graham Yost: Johnny has opened a little bed and breakfast in Corben. No, we got stuck at the end of 12, and there was only so much real estate in the final episode, and we really wanted to focus on Raylan and Boyd. We did let Johnny dangle. He's out there in the wind. To us, it's a good thing to have dangling in the wind. I don't know how, where or when he'll be used, but there's obviously a big X on his back, and on Moonie and Lee Paxton's backs, too.

We began this season talking about Art's impending retirement, but only a couple of weeks have passed for the characters. Is this going to be a situation like Unser's cancer on "Sons of Anarchy," where Art's always getting close to retirement, but stays in the job for the life of the show?

Graham Yost: I would suspect that Art will be in the job pretty much as long as the show goes on. I can't say that definitely, but it feels that way. Nick's doing a great job and is so much fun to have as part of the whole thing. There's a solidity to his performance and the character that is really really important to the show.

Earlier in the season, it was suggested that Boyd was putting himself deep in debt to the Detroit mob in order to execute his moves against Lee Paxton and his buddies. With Theo out of the country, Nicky dead, and Wynn Duffy back from Canada, is that debt forgiven?

Graham Yost: That's our feeling. We feel that with the death of Nicky Augustine, and the disappearance of Theo, that Boyd is working now for Duffy, and by extension for Sammy.

You said one of your goals this season was to do a better job of writing for Tim and Rachel. How do you feel you did?

Graham Yost: I think there's still places to go with Rachel. I know that people who watch the show have been picking up on a certain chemistry etween Raylan and Rachel — some of that is planned and some is just what's happening between the two actors — so there might be something along that road. But I would hesitate to really say anything more about that. Gutterson will be interesting to follow. I feel like we did a good job with him. The stuff with Colt was fun and it gave him a drive. I felt like, in a strange way, the peak of that relationship was in 11 with the convoy shutdown and the phone conversation between the two of them. That was really fun. And Jacob said to me that that episode was perhaps the most fun he's had on the show so far.

Well, let's talk about "Decoy." People (myself included) went nuts for that episode. What was it about that one that made it so successful, and is that something you can try to engineer in the future, or simply something where all the elements happened to come together perfectly? 

Graham Yost: I don't know if it's something you can try to engineer. The goal for it was to just be a really fun episode with a lot of tension. We've sort of done one of those a season. In season 2, it was Raylan and Winona trying to get the money back into the evidence locker, and there was one last year where it looked like Raylan was framed for murdering Gary and him trying to escape from that. And that was a pretty good episode. One of the common threads is that I was involved in writing all 3 of those, and that's just something I really like to do. I like those high-tension structural episodes where there's a clock and people are in desperate straits. But then I think for "Decoy," even within that structure, there were these moments where things to to slow down. We got the phone call between Gutterson and Colt, the stuff between Raylan and Rachel and Shelby, and the big scene between Nicky and Ava, which is one of my favorite we've ever done. A lot of that was Mike O'Malley inmprovising that stuff, but also the way Michael Watkins directed it throughout, and also what Joelle did in that scene and what David Meunier did as Johny. Boy, I think we set out on every episode thinking that this is just going to be a great, great episode. Sometimes it is, and sometimes it isn't. Now, it was also a big episode for us. We go over our pattern budget with an episode like that, and the next episode we were back under, and were right around on budget for the season. So you can't do that every week. And it's also not entirely our show, you know what I mean? You don't usually go that big. But it's fun to do every now and again. But I don't think you can really plan it: "Okay, every year, episode 11 is going to be like that!"

Had you specifically planned to bring back Limehouse towards the end of the season, or did the story just go there and you realized Mykelti was available?

Graham Yost: We've been talking about how we could use Limehouse. We didn't want to just use him — just spot him in the season. Fred Golan had an idea, because we all love Dewey Crowe, that while Shelby and Ellen May are trying to get out of Harlan, we just see Dewey Crowe run across the road to establish that he escaped from prison. (With Limehouse), it really needed to be something that had some weight to it. So when we came up with this story for Limehouse: How far will he go to achieve his ends? He is the wiser man, and sees that if he keeps going down this path, he's going to lose everything — lose his soul. We thought that was resonant with where we were going, and it turned out that Mykelti was, in fact, available.

And does Constable Bob still have his job? Will Patton Oswalt be back?

Graham Yost: Yeah, Constable Bob still has his job. We just have to see. It's always our fear with these characters everybody loves: we're just terrified of wearing out the welcome. How much we see of Bob next season, I can't say. But I know that Bob is a big part of the show going forward.

How far away are you from having to start really writing the season? Do you have any ideas yet on what you're going to do?

Graham Yost: Right now, it's just noodling with a yellow pad, and having conversations when I get together with Fred and the other writers. We just talk, and figure out what's of interest to us. We'll start in earnest in the early part of July. Hopefully, that's enough (time). Each subsequent season becomes tougher to a degree. On the one hand, you know what can work and what doesn't work, it's the "what doesn't work" thing that starts to narrow the path. "Well, we need stories to fit in these parameters, and finding them becomes harder.

You brought in Gerald McRaney this year, and Jim Beaver got a lot more to do before he was shipped out to WitSec. Who's next on the "Deadwood" guest star wish list? Is it Ian McShane time yet?

Graham Yost: (laughs) With me, it's usually "Deadwood," "Boomtown" or "The Pacific."

But clearly there's a "Deadwood" arms race going on between you and Kurt Sutter that will not be completed until one of you bags McShane. Don't you want to be the victor?

Graham Yost: We'll see. We've talked about it. It's just trying to talk about the right thing for him, and again subject to availability. Believe me, if we got a call from Ian McShane saying he wanted to be on the show, then maybe we would try to focus on that and find something for him. A little bit of that happened with Gerald: interest was expressed, and Tim's known him for years, and we thought this character might be a good fit for him.

You say it's getting harder and harder. If you had your druthers, how much longer would the show run?

Graham Yost: Druthers, really, six years. Two more seasons. It's difficult. Tim and I will both say that it's the best job we've ever had in many respects. And Tim would say he'd happily play Raylan for the rest of his life, but then it's finding the stories that really intrigue us. And in terms of this world, a big part is the Raylan and Boyd relationship. How many more moves do we have of that? That almost becomes a bigger concern. And just the Kentucky of it. if we were to move the show outside of Kentucky, it would be a very different show that we couldn't put under the "Justified" banner anymore. "Justified" is Kentucky.

Alan Sepinwall may be reached at sepinwall@hitfix.com