"Boardwalk Empire" concluded its third season tonight. I reviewed the finale here, and I have an interview with series creator Terence Winter coming up just as soon as you get me a clean gown...

The first time we see Nucky this season, it's a classic gangster moment, where he orders the thief shot in the head, yet it's not until the last scene of it that he seems to fully accept it when he finally takes the flower off his lapel after he gets the "Are you Nucky Thompson?" What did Nucky learn? Has he finally accepted that this is who he is now?

I think the full realization of what it means to be a gangster finally sets in by the end of the year. The whole "half a gangster" thing sort of cuts both ways. You can't survive as a half a gangster. You can't be this public figure, glad-handing strangers all the time. You've got to start thinking about keeping it a little more low key. By the end of the year, I think Nucky has learned a lesson. He says to Eli in the finale, "I don't want anybody coming close to me that we don't already know." He's a different guy.

He wants to keep people at a distance, and yet there are a bunch of moments in last week's episode where he seems to recognize how insulated he's become. He doesn't know Chalky's phone number and knows nothing about Eddie, and he realizes, 'Hey, maybe this was a mistake. Maybe this is why I'm in so much trouble now, because I've been off dealing with Billie Kent and other things and not dealing with the people I work with.'

To survive in this new world, the people who have your back and who are closest to you, it might be a good time to sit down and have coffee with the help, you know. These are the people who his life depends on. There's some real moments of clarity there. It's like Chalky says to him: "You go without, and find out what you really need." You find out who your friends really are.  It's definitely a wake-up call to Nucky that maybe Eddie Kessler is somebody worth getting to know a little better.

Did the writing of this season feel different, not just because Jimmy wasn't around but because Gyp was a more classical gangster movie kind of anatgonist than some of the previous people Nucky's gone up against in past seasons?

Every season has felt like its own completely separate movie in a way. It's all depending on what the circumstances are. It had its own challenges. Some of it was more fun, some of it was more challenging, some of it was difficult, but it's all part of the same piece, obviously. But each season, depending on the circumstances, just feels vastly different to me.

Even with the people who died last season, this is still a huge cast of characters, and now spread even wider than before. So Chalky was missing for the middle of the season, Van Alden tended to pop up every other episode, Richard was absent for a while and then very important at the end. How do you try to balance that out, in terms of having all these great actors and characters to work with, but who aren't tied in to what Nucky is doing every minute?

That's always been the nature of the show, and always been one of the challenges of the show. On the one hand, one of the first rules of show business is "always leave them wanting more." We've got so many fascinating, compelling characters, and they'll appear and disappear for a while. The reality is, we just couldn't possibly fit, everybody can't have a storyline in every episode, there's not enough time in the hour. In general, we can't service every character in every episode as much as we'd like to. Some of our first drafts come in at 80 pages, and they have storylines that involve Van Alden or Richard, and we just have to pick and choose. It's really just a question of balancing the storylines over the course of 12 hours. After a while, it's like cooking a good meal: you add a little flavor here, or this there. You really want to get back to Van Alden, or see Chalky or Capone, but you don't want to just wedge them in there if they don't fit into the bigger story you're telling. I look at the season as one piece, even though it's broken up into individual episodes, or chapters of the book. They're all one big story. Samuel was a good example; we only saw him before in episode 2, knowing full well that he'd pay off in a huge way in episode 11. I knew he had a memorable enough turn in episode 2 that I didn't feel the need to have to go back and revisit him to remind people before 11 who he is and what he's doing. It's sort of like music. You plot it out and you hear the notes as they fall on your ear, and you go, 'This sounds right.' Once you're anticipating getting back the characters you really like, but sometimes it doesn't work that way.

You said that it's like a book, and David Simon used to always say that about "The Wire," and he says it now about "Tremé," and that you can't judge the story in episode 4 until you get to episode 12.

That's what's challenging for us about the abundance of weekly recapping and people making these declarations about whether something makes sense or not, 'This felt like treading water.' Yeah, taken on its own, it might, but trust us that it's all part of a bigger piece. It's a cog in a much bigger wheel, and it will pay off. Things don't happen by accident, they're there for a reason. We're well aware of that. It's like reviewing a book chapter by chapter, and just saying it doesn't work.

Samuel was obviously one of those; when he popped up again to save Eddie's life, I said, "Of course." And we spent a lot of time with Margaret in the hospital on the childbirth class, and it seems to pay off with her having to get the abortion.

Yeah, of course.

How much of a challenge is it to come up with stories for Margaret at a time when she wants nothing to do with Nucky. You've got Kelly Macdonald, she's a great actress and you obviously want to have her on the show, but how do you use her, given that she, in her ideal world, would run off to Brooklyn and never go back?

Well, that's sort of what happened. The bigger question is season 4. We're already working on that. There are ways to integrate her character back into Nucky's world. So stay tuned for next September. It is a challenge. It's very similar to the challenge of writing Carmela Soprano. Realistically, this is an intelligent woman who is questioning what she's doing with this brute — why wouldn't she just leave? Psychologically, sometimes people just stick in their situation even if it's bad for them. In the case of Carmela, it was increasingly challenging to have her complaining and have her in danger, and then the same thing with Margaret. You would think, "Just pack up and go." Then they're off your series, of course. But people do stay in relationships for all kinds of reasons. This season was a journey for Margaret, seeing the woman fly away in the plane, asking what's her journey, and she finds a cause that's worthy of her time and ambition.

The one thing I often hear from people is that they really really have liked it when Margaret has wound up playing Nucky's unofficial consiglieri. That's not a role she wants any part of anymore, though I suppose we got a little of it in the episode after the bombing. Can she get back to that place? 

Anything's possible. We're making up the story as we go along. If we wanted to take her in that direction, I guess we certainly could. She's certainly capable of giving advice, but I don't know if that really feels to me like who Margaret really is or who she wants to be.

Richard has become one of the fan favorite characters, and his rampage through the Commodore's house in the finale is one of the most memorable sequences of the finale, if not of the entire series. People keep waiting for the moment when he's going to go work for Nucky so he can become even more prominent. I know you love Jack Huston and this character, but what do you do now with him at this point?

That remains to be seen in season 4. All of what you've said is true: he's a fan favorite, he's a favorite of ours. You do want to see more of him, you do want to see him and Nucky together, and we're well aware of that, and possibly that's what'll happen in season 4.

So let's talk about what was up with him in season 3. As with Samuel and Chalky, there was a time earlier in the season where we were visiting Richard and visiting Gillian, and not entirely sure what was happening beyond seeing them. And then later it became apparent how this tied in to everything else. At what point did you decide, "We're going to build up to a moment where Richard gets out every single gun he owns and starts killing everyone in sight"?

Pretty much early on, we knew the resolution of the Gyp Rosetti story, a lot of different stories would be converging toward the finale. We knew Richard would factor into it, not in such a direct way that he's part of Nucky's gang; his story was going on its own trajectory, and those two stories would converge when Gyp ends up at the Artemis Club. We knew that fairly early on in plotting out the season. We also knew how frustrating it would be for some people in the audience where all they want to see is Richard take out his gun collection. For us, it was equally interesting, if not moreso, to see Richard as a person, and just see him fall in love and try to have a normal life, knowing full well that those guns are coming out. I knew people had just been waiting and waiting and waiting, and the anticipation had been building. He hadn't done anything violent in a while other than throttle Julia's father. And then the rampage, which hopefully people who are inclined to like that sort of thing will be satisfied with. I certainly was. Tim Van Patten did just a phenomenal job directing it, as did Jack performing it, and everyone else.

In terms of Gyp, sometimes the antagonists on "The Sopranos" would die at the end of the season, while at others they would stick around. Was there any thought to keeping Bobby Cannavale around, or did you feel Gyp was too much of a mad dog and had to be put down?

That's the challenge with all of our great characters who've died. They're so great. You want to keep them alive. But for me, the most satisfying resolution to looking at the season as its own book was that Gyp's gotta go, and in a way that's unexpected and powerful. He's just like a mad dog and just needs to be put down. If he didn't go in 12, you'd think he's gotta go in episode 1 of season 4, so what are we waiting for. The guy's gotta die.

Does Gillian die from the heroin overdose?

No. You're not the first person to ask me that. She does not.

So if she's not dead, then I imagine she is not going to be happy to find that her grandson has been taken from her.

Probably not.

That certainly could have been an easy way to kill her off. Why did you decide not to?

I guess we just felt there was more story to tell.

What exactly is Nucky's play with Rothstein and Mellon and the Overholt distillery?

Nucky realized if he held out enough bait for Rothstein to want to make a deal with him that he could get Rothstein to abandon Masseria. So the big thing Nucky had was the huge distillery, so he has Mickey call Rothstein and lay out some bait, "Nucky's got this huge distillery, would do anything to get out of this trouble." Rothstein says let's make a deal, and I'll get Masseria away. After Nucky gives Rothstein what he wants and Nucky gets what he wants, he calls Mellon and says, "You've got criminals in there, shut the place down," and Rothstein ends up with nothing.

Okay, so I want to be clear: this is Nucky abandoning the distillery, rather than finding a clever way to cut Rothstein out of it, right?

No, he imploded his own deal.

Mellon didn't want anything to do with Nucky to begin with, and I assume he certainly wouldn't want to after this.

Yeah, I don't think they're friends anymore.

Why does Nucky have Capone take out all of Masseria's men rather than simply let them leave town abandon Gyp and go back to New York? Is it just part of the message he wants Tonino to relay to Masseria? That a show of strength would be greeted with respect rather than a desire to keep the war going?

It's both a show of strength to Masseria and a way to fuck over Rothstein, who just convinced Masseria to pull his guys out of Atlantic City.

In terms of Rothstein, a question that's come up a lot from fans is your willingness or lack thereof to change history. Lucky got arrested on a drug charge around that time, and you worked that into the show. As the series moves further along, do you become any more willing to say, "Okay, I know these people are real and this is what happened, and this is how they died, but maybe for the sake of this fictional show, something else might happen"?

Not in terms of story points, like how Rothstein died and the basic circumstances surrounding it. Lucky's arrest is a good example. He did get arrested, he did give up his own heroin to get himself out. I took those basic facts and said, "What happened when they gave up the heroin? Who were those cops who arrested him? Were they dirty or clean?" Those were the things I played with in terms of the fiction of it. But the general timeline and historical points of their lives, I won't change. Luciano was arested in 1923 on a drug charge. If we were in that zone in our time frame, it had to happen. I won't ignore it.

Could a wiseguy just take over a town like Tabor Heights back in the day?

Yeah, it actually happened. This is all based on a real incident in, I think, the Atlantic Highlands. It was basically a gang of bootleggers who realized this was a small Methodist town, quiet little place where nobody paid attention to anything, and it had its own beach access to the ocean. The whole thing culminated in a giant gun battle on the beach on, I believe, July 4, 1923, I believe in the middle of the day, with guys running into water with machine guns. That was the inspiration for this. We thought it was a great, forgotten historical story and we thought it would be fun to do.

I want to go back to the Billie Kent arc. He neglects a lot of his business while tending to her. How did that play into this arc of Nucky becoming more of a gangster?

Based on the relationship with Margaret falling apart, he's back to his old ways, Billie is a young, fresh, sweet playful girl, and has a little bit of a sexy side. It's just Nucky taking his eye off the ball, fixating on her instead of his business. As he says to Billie, "I just want everything to run without doing anything." And that's not how the world works, and the gangster world. She has a different energy, and is really fresh and fun and sweet, and was a different way to go for him.

How much fun was it writing for, or simply watching, Stephen Root as Gaston Bullock Means?

Oh, it was great. For me, the flowery dialogue, and the conniving, duplicitous, Foghorn Leghorn-ish flourishes of his dialogue was so much fun to write. He completely gets it and knows how to do that character to the limit. He was great. Exactly what we hoped for. He was a joy to work with. I've been a fan of his for a long time. Such a chameleon.

Is he available for season 4?

We certainly hope so.

Speaking of season 4, I'm excited to hear that both George Pelecanos and Dennis Lehane will be writing for you next year.

Yeah, very excited to have them on board. We're just getting started.

How did that come about?

"Tremé" was coming to an end, I've always been a fan of George's, and just put feelers out, and it turned out he was a fan of the show and had worked with Tim Van Patten before. So we spoke, we had dinner, and we just made a deal. Dennis Lehane, same thing, I think he'd been involved in "The Wire" to a small extent. It's sort of in the same universe, so we reached out to Dennis.

Who burned down the greenhouse? Teddy is playing with kerosene, but he blames a gypsy, and then when Gyp calls the hotel suite, he tells Nucky that the gypsy is calling.

A drifter. In Teddy's imagination, it spun out of control, and in a child's mind, you hear "Gyp," you make the connection. Teddy doesn't know what happened to the guy. For all he knows, that was the gypsy on the phone.

What did Lucky whisper to Masseria? Did he know more details about Nucky's assassination attempt than we thought he did?

It's just that Nucky is going to move on you. Nothing specific. Just "Be on your guard."

How did you decide not to show the failed hit, and simply have Owen entering the steam baths, and the next we see him, he's in a box?

We originally were going to show the actual hit gone wrong inside the steam baths. This was just a bizarre, fortuitous mistake that happened. The day we were going to shoot the steam baths, there was a problem with the location. It was a very old building in Brooklyn, and a plaster rosetta that weighed about 30 pounds in the vaulted ceiling, fell down and crashed about three feet from a crewmember. We had already shot the lobby scene and pulled the plug and thought, "We've got to rethink this," and in the discussions after this, I think it was Tim Van Patten who said, 'Do we really need to see this? Wouldn't it be better if we didn't see it?" And I thought about it and decided to wait to get the cut of the episode back to decide, and it was so much more powerful without knowing in advance, and we ended up leaving it. You almost forget in the episode, 'Oh, right, Owen's off doing that.' So many people were surprised he was in the crate. That episode on the set made the episode a little better, and probably saved us a little money.

Alan Sepinwall may be reached at sepinwall@hitfix.com