Person of Interest type TV Show network CBS

[SPOILER ALERT: Stop reading if you haven’t watched Tuesday night’s episode of Person of Interest!]

After setting up the possibility that Detective Fusco (Kevin Chapman) would be the one to kick it, Person of Interest creator Jonathan Nolan and EP Greg Plageman threw audiences for a loop by sending beloved cop Joss Carter (Taraji P. Henson) to an early grave on tonight’s jaw-dropping episode.

EW talked with Nolan and Plageman about what went into the decision to kill off Carter and how they managed to keep it a secret from…well, pretty much everyone. (Also, check out our interview with Henson!)

ENTERTAINMENT WEEKLY: You guys, I’m devastated. This is awful!

JONATHAN NOLAN: We know these things are very traumatic for the fans, but Greg and I have been consistent in this from the beginning. Film is like a one-night stand, and TV is a relationship, and I knew that people watch this show like an extension of their family: you bond with the characters, you connect with them. But from the beginning, every one of our actors has understood that our show is a blended model, very self-consciously in the image of The X-Files, which I felt was an almost perfect TV show in that balance between case of the week and serialized. If you’re really telling a story about characters and want the audience to invest, you have to make the devil’s bargain when you set out to design the show. For the audience to be completely invested, you’ve go to be willing to go there. Our joke to the cast has always been that someday Greg and I will write ourselves off the show.

How did you anticipate the audience reaction to this episode?

GREG PLAGEMAN: I think it’s going to run the gamut. There are going to be some people that are totally shocked. There are some people who are wedded to that character and will be very upset about it. But we feel like it just has to be that way in order to be a fresh show where you feel like anything can happen. TV can begin to feel like a commodity, something stale and predictable, and that’s something our show just can’t be. If you can come in and expect all your characters to escape unscathed, it lacks a certain amount of gravitas.

So you two and Taraji knew that Carter would eventually die, but did you know that it would be this season, this episode, this moment?

NOLAN: We felt from the beginning that this is where we’d want to go with Carter by the third season. Real characters have real journeys, and that means that requires an end. So we came into this season knowing that the middle of the season is a place where the audience tends to fall asleep a little bit, but there’s a tremendous opportunity there. Frankly no one’s expecting this in the middle of the season. We’ve consistently had these midseason moments where we put our characters in jeopardy, but if we did another one of those and it wasn’t the real thing, you get to a point where the audience is starting to get turned down on us.

What other shows do you draw parallels from in terms of midseason shockers?

PLAGEMAN: The shock of what happened to Stringer Bell on The Wire is something people will always remember. We always feel like that was a place our show had to go. We feel like we’ve been able to plan for it, though, so it’s always been baked into the DNA of the show.

NOLAN: I remember exactly where I was when Stringer Bell was killed because my wife and I used to argue about whether or not we would watch Veronica Mars or The Wire on Sunday nights. On Monday I opened the New York Times website and the first story in the arts section was ‘Can you believe they killed Stringer Bell?’ And I was so mad at my wife for not letting me experience that in real time.

How did you keep tonight’s big twist a secret?

PLAGEMAN: It’s a stealth operation. It gets harder and harder and harder. Casting breakdowns, people on the street snapping photos of our set, knowing what episode we’re on, who’s there, who’s not there…it makes it extremely difficult. You basically have to go into radio silence and shut it down.

NOLAN: You get a little self-serious about these things and you start treating them like state secrets, but it’s really all just about preserving the experience for the audience. A long time ago, the Internet was a great tool for disseminating cool buzz about what’s coming down the line. But script leaks and casting breakdowns…fans can get this information if they want. And there were a couple of years when we started seeing a kind of maturing of that. I was astonished when I saw that no one had spoiled the Red Wedding episode of Game of Thrones. The fans who had read the books huddled a little bit to protect the experience for everyone else.

I have to say, some Person of Interest characters seem to always be having close calls. Carter has had them all season.

NOLAN: Reese says to Finch in the pilot, ‘If we keep doing this, we’ll both probably wind up dead.’ And he’s telling the truth, and we’re telling the truth as writers in that scene. We’re not bullshitting around. All of our characters are gonna bite it at some point. The nature of what these people have chosen to do is extremely, extremely dangerous. That’s how the show works, and you have to watch because we’re not going to save it for the season finale.

Any chance we’ll see Carter in flashbacks, or is this the last we’ll see of her?

NOLAN: Oh I hope not. This actually makes these decisions easier on our show, because people on our show live forever in flashback. Taraji is an incredible actor and a pleasure to work with, so we will be doing everything we can to revisit and get a chance to work with her again.

PLAGEMAN: Brett Cullen’s character has never actually been alive on the show!

Take me through the night of filming, and when the crew found out.

NOLAN: Secrets are fascinating creatures. To protect everyone from themselves, we told as few people as possible. Taraji had been in on it for a long, long time. We hadn’t shared that with anyone else on the cast and crew because you’re not doing anyone any favors when you hang that in front of them. And then as we got closer to it, Greg and I sat down with the other cast members and told them what we were doing. That was the first taste we got of what we’ll get from the fans. There was a real grief.

We told the department heads where they were going to need to be, that they’d need some lights, that we needed the following actors, and some squibs, which are the explosives that we use to simulate gunshots. And we showed up. We gave Taraji, Jim, Robert John Burke and Michael the pages, but we just printed those up without them ever being included in the script. Then we asked Kevin Chapman to join us – we’ve steered the promotional materials towards this big lie that we’d toss Fusco.

And you filmed an alternate ending in which he takes the bullet instead.

NOLAN: The audience has become very sophisticated, and in an age in which there are no more secrets, we were happy with a lie. A lot of the folks on our post-production team worked on Lost and they had an episode in which the big question was, ‘Who’s in the coffin?’ They shot it a few different ways with different characters, and in every stage, all of that was super helpful. I took our hard drives to the post-suite personally because that avoided them being anywhere near an Internet.

Any parting words for Carter fans?

NOLAN: As difficult as it is to say goodbye to a great character and the opportunity to work with a great actor, our fans hopefully understand that the show wouldn’t be the show if we didn’t do these sorts of things. We’re guided here by our own experiences as audience members and fans, and it was these moments that, as difficult and traumatic as they were on shows that we’ve loved, are the memorable moments.

PLAGEMAN: We feel as though this is our show, and this is what makes our show compelling, and we certainly hope viewers continue to watch.

What’s coming up next week?

PLAGEMAN: Episode 10 is called “The Devil’s Share” and it deals very explicitly with the fallout from this episode, in which Robert John Burke’s character Simmons has killed Carter and his number comes up. Finch is confronted for the first time with a conundrum: someone’s going to die and it’s probably going to be at the hand of one of his allies, but he doesn’t know which one.

Person of Interest airs Tuesdays at 10 p.m. ET on CBS. Read our Q&A with Taraji P. Henson about the latest episode here.