The CBS drama series Person of Interest is not your typical procedural. Sure, its characters have cases to solve every week, but there is also an ongoing mythology, character development you can really invest in, and major character deaths that affect everyone.

While at the CBS portion of the TCA Press Tour, executive producers/writers Jonathan Nolan and Greg Plageman spoke to Collider for this exclusive interview about when they felt they really hit their stride with the show, that they do consider the show to be a procedural that also happens to have a variety of other elements to it, how equal thought went into both the recent episode where they killed off a main character and the episode immediately following it with its aftermath, where things are headed for the rest of this season, and how they will be focusing on artificial intelligence as a commodity and the possibility of another Machine. Check out what they had to say after the jump, and be aware that there are some spoilers.

Collider: This show has really been on fire for awhile now, but when did you feel like you hit your stride?

GREG PLAGEMAN: That’s a good question. I think around Episode 4 (“Cura Te Ipsum”), in Season 1. We were trying to figure out who these characters were and what they could do, and tonally, for me, that least scene in Episode 4 was really like, “Can we do this?” And Jonah was like, “I don’t care. Let’s do it!” And I said, “All right, let’s do it!” It was the episode where Reese (Jim Caviezel) had sat down with the guy who was the perpetrator, at the end, and told him the dilemma. And the conundrum of what to do with this man was really, really cool. Ending with, “What is Reese gonna do with that guy?,” gave it an element of danger and also a lack of resolution that I found pretty thrilling. I thought that was really cool. I was like, “We can do this!”

JONATHAN NOLAN: Yeah, I was very proud of that episode, and I was very proud of the ambiguity, at the end, and the warning shot it fired for people who were watching the show. It was like, “Oh, this is gonna be a different thing.” It’s funny, shows, in general, say that it took awhile to find its pace. But, I honestly feel like Greg and I have been doing the same thing, from day one of shooting the pilot, onwards. And then, as you make more episodes, it reveals itself, but we’ve really done the same thing. The first six episodes, very carefully and assiduously set up Enrico Colantoni’s character Elias, who appears in Episode 7 (“Witness”). I love the end of Denise Thé’s episode (Episode 4), but because it’s a one-off episode, for me, when you look at the end of Episode 7, where you get to the moment that they’re wrapping it all up, and they get the guy and arrest him and it’s cool, that’s not at all what happens. Fred Toye, who’s one of our favorite directors, directed that episode. He has this last fucking phenomenal shot of Enrico and his guys, walking off down the boardwalk, and they went to Coney Island to get it. It’s total victory for the bad guy. And the network let us do it.

PLAGEMAN: But it freaked ‘em out, and that’s how we knew we were in a good place. They were a little worried, which was good.

NOLAN: Yeah, that’s very true. Everyone has been incredibly supportive, but it’s always so much fun to go in and have those meeting where they go, “Oh! Oh, shit, okay!” The executive that we work with watch the show, the same as we watch the show. We’re on this story together. But occasionally, you throw them a doozy like that, and it’s great fun to see their reaction first. And then, you imagine the audience’s reaction. We’ve always taken that principle, from the beginning, of making a procedural using The X-Files as a model, for assiduously trying to build story. And obviously, there are developments with the characters, and we’ve added cast members that are phenomenal. I feel like I’ve been very excited about the things we’ve been able to add to every episode. But from the beginning, I’ve had a good grasp of what the show can be, and we’ve just been doing it. And people have been finding it, which is really exciting.

Do you still view this show as a procedural?

NOLAN: We’re happily, proudly, avowedly a procedural. We have our random access case-of-the-week. It’s an incredibly durable and compelling storytelling format. There’s nothing to be embarrassed about with it. Cable has this great energy right now with these purely serialized shows, but it’s very, very difficult for people to sit down and commit to watching. There’s the binge-watching phenomenon, which is great. We have this massive audience that connects with us, week in and week out, but not always every week. We understand that dynamics of the way people watch the show. CBS has incredibly sophisticated levels of information about the way that their audience watches the show, and we have a great understanding for how the audience absorbs our show. The idea that you can have a case-of-the-week in a show that continues to propel character along is how I understand TV. I grew up watching Magnum, P.I. and shows like that, where you could develop a character over eight seasons, with stories along the way.

PLAGEMAN: There’s the stand-alone aspect of the story, and then there’s always gotta be this larger serialized aspect. There’s always gotta be some sort of mythology pushing that bigger story forward. When it’s not there, there’s an emptiness to it. Anything that veers towards something more formulaic is just depressing. We don’t want to work on that show. So, the general rule is, “Does this intrigue us? Is this something we want to watch?” If it is, then we’ve gotta do it. I don’t really look at it as burning story. It’s more like, “Are we telling enough compelling story to push people to say, ‘You have to be watching this show’?” That’s worthwhile television. The issue that some people have with broadcast television, or when procedural became a dirty word, was when it started to feel formulaic and that you didn’t need to watch it to know what’s going on. You need to watch our show to know what’s going on. We’re continually walking that line. We want to be an inviting show that people can drop into and figure out what’s going on, but there’s always that aspect of, “I don’t understand that ‘cause I haven’t been watching. I need to watch this more often.” That’s the line we’re continually walking.

How much thought went into killing off Carter (Taraji P. Henson), and just when the best time would be to do that with the most impact?

NOLAN: We talked about it to the degree that we didn’t let the story dictate it exactly. We talked about doing it in Episode 9, quite consciously, because no one would fucking expect it to be Episode 9. We knew we were doing Episode 10, and then we wound up doing Episode 11, before the winter break, so we knew it wouldn’t be the fall finale, or whatever they call it. That term doesn’t reflect the fact that we just continue making episodes through the year. I was like, “Fall finale? Oh, great! We get a vacation?” But no. So, we figured if we did it in the episode before, we’d catch everyone off guard, and that actually worked out quite nicely. We collaborated with the network and said, “We’re doing this big thing and we want people to watch, but we don’t want to give it away.” They very helpfully collaborated with us to lead people to believe that Fusco (Kevin Chapman) was getting written out of the show.

Was it always going to be Carter, or had you considered killing off another character?

NOLAN: Well, from the beginning, we told all of our actors that any of them could buy it, at any moment, which is always a bracing conversation. But, we decided last year that that first major move we were going to make would be Carter. We got so much fun out of the H.R. storyline, but we felt like, if we kept spinning that out indefinitely, it would wear out its welcome. It sucks because, in addition to not working with Taraji – although everyone lives forever in flashbacks on our show, so we know we’ll get to work with Taraji again – Robert John Burke is a wonderful actor, as are all of the other actors we worked with on that storyline. Clarke Peters is an actor that Greg and I had both long admired from The Wire and were incredibly excited to work with. But, we didn’t want to just spin that storyline out forever.

Because Carter was so intrinsically plugged into that story, it felt like there had to be a casualty. Frankly, if we’d killed off Fusco, everyone would have seen that coming a mile away. People thought we were going to kill of Fusco in the first season. Kevin Chapman thought Fusco wasn’t going to make it out of the first season. We had a very emotional conversation about that. So, that was something that really drove it. We wanted to do something a little different. And what’s fun about a major character meeting a grisly end on your show is that it’s a catalyst for viewing the other characters and the journeys they’ve taken.

The episode after which Carter was shot, called “The Devil’s Share,” was an episode we talked about almost as much as we talked about the episode before it. We wanted to turn the fall-out inside out. The episode was about Fusco, and it was the conclusion of his journey from bad cop, where we find him in the pilot, to being redeemed. He has been redeemed through this friendship and connection with someone who is purely good and un-compromised, and it has lifted him out of the muck. It’s not Reese’s story. It’s not Finch’s (Michael Emerson) story. In that moment, in that episode, it’s Fusco’s story. In that episode, for the first time, a number came up where it was one of Finch’s friends who was the perpetrator. That was a really great jumping off point. We’re always trying to reinvent the franchise of the show. But what it became a mechanism for was understanding that this arc has been Fusco’s redemption. It was incredibly satisfying for me, after two and a half years of working with that character, to see such movement.

Was it important for you to make Reese struggle with Carter’s death, and not just have him return to working with Finch, like nothing happened?

PLAGEMAN: Yeah. You can’t stand it when you watch a show and something incredibly traumatic happens, in the season finale or with a cliffhanger, and then with the next episode, it’s easily resolved. We didn’t do that between Season 1 and Season 2, when Finch was abducted by Root (Amy Acker). We said, “Let’s turn this into an arc. Let’s let these characters take us where they want to go.” So, in the same way that “The Devil’s Share” was about Fusco’s transformation and how Carter changed him, we would not be playing it honest with the audience, if the loss of Carter didn’t affect Reese, in some way, in terms of a certain amount of disillusionment with The Machine. This is something that was designed to protect acts of violence, and it still couldn’t save Carter. In episode “4C,” it was the end of a three-episode arc of Reese going off in the yonder, and then coming back full-circle and being pulled in, almost by The Machine itself, to recognize the importance of what he was doing. But you’re absolutely correct, in that we always have to be a show that deals honestly with these traumatic events, or else it just feels false.

Where do you go from here with the story, and how will the dynamics be different?

NOLAN: Hopefully, the ratings will help with this, but it feels, to us, like we’ve barely begun. This is the first chapter of the show. That’s why it was really important to us that Episodes 11, 12 and 13 set up the shape of where the second half of the season is going, in pure storytelling. We spent the first half of the season looking at H.R. and that creeping municipal threat and corruption. That was the Serpico aspect of our show. But, Episode 11 and 12 set up the idea that The Machine itself is this object of desire, not only for the people who used to have unfettered access to it, but also the people who would control it and the people who would destroy it. That’s where our season plunges head-long into some of the debate that we think and, frankly, hope will really crystallize over the actual real world surveillance, just in terms of that ongoing argument about, “What the hell are we going to do with all of this information?”

Obviously, we’ll keep our other storylines going, but the second half of the season plunges head-long into the question of, there has been one Machine up until this point, but what we’re describing is a commodity artificial intelligence, and those things are being developed right now. They’re probably still years and years away, but Greg and I have spoken to some of the leading people in the artificial intelligence community, and they’re making strides in this direction. When they emerge, in whatever form that takes, the only thing you can guarantee about the form A.I. will take when it does emerge is that it will be surprising. I will forgo predicting what that will look like, but I guarantee you that there will be more than one. So, this question of the possibility of the emergence of a second Machine sets up the second half of the season. That’s something that we’re really going to dive into, for the rest of this season.

Person of Interest airs on Tuesday nights on CBS, and returns with new episodes in February.