Slow Horses Showrunner On Season 5's Tonal Shift And Making The Most Of Its Most Annoying Character [Exclusive Interview]

"Slow Horses" is back, and there's a bit of a vibe shift this season. Slough House's resident tech guru and overconfident blowhard Roddy Ho (Christopher Chung) has a girlfriend, and considering his questionable dating history (he was scammed by a bot in a previous season), this new relationship naturally raises some red flags for the slovenly but ruthlessly effective MI5 agent Jackson Lamb (Gary Oldman). With Ho being front and center, this season is automatically going to be funnier than season 4, which was a dark exploration of River Cartwright (Jack Lowden)'s family lineage and buried secrets finally coming to light.

I recently had the opportunity to speak with showrunner Will Smith about that tonal shift. He's orchestrated the entire series so far, but is stepping away from the show after this season. In our largely spoiler-free conversation (we touch on the very first scene of season 5, but otherwise discuss bigger picture aspects of the show), we get into that Ho-centric vibe shift, Smith's careful approach to that harrowing opening scene, the props he was given when he left the series, whether he'd be interested in returning to oversee a spin-off, and more.

Note: This interview has been lightly edited for clarity and brevity.

This past summer, word came out that this would be your final season with "Slow Horses." How did that decision come about?

Will Smith: Well, sadly, it was a practical decision just based on the looming need for scripts for series six. And I was doing so much work on series five that there was no way I was going to be able to do that. I don't want to leave, but it was also like, I couldn't get the scripts ready, they couldn't meet the schedule, so it was with great sadness on both sides. But I also feel I've taken the show to — it doesn't conclude anything by any means, and the show is going to go on to even bigger and better things and Mick has just released the ninth book, and I'm sure there'll be a 10th, 11th, 12th. So it's going to go on and on. But in terms of my contribution, I feel it does conclude certain arcs that were started in series one. I don't want to give any spoilers, but it feels like a nice place to exit. The show is in a good position, I hope, creatively.

My understanding is that when you were writing season 5, you were simultaneously shooting the fourth season and editing the third season. So did you know that season 5 would be your last when you were writing it? Did you have that sense of, as a writer, being like, "Ah, I'm putting the final touches on the last script that I'm going to touch"?

There were a few moments where it was like, "Oh, this is the last day I'm filming with these actors," and things like that, and that was very emotional. But it also keeps going. You finish the shoot, and then you've got the ADR and then there were some pickups and then we had the cast and crew screening on Sunday. It was fantastic to see everyone again. And then, I'm helping with the — Roddy Ho is doing an AMA on Reddit shortly after this, and I'm part of that. So it's like, "Oh, I haven't left yet." That hasn't hit me, but I'm sure when it does, it'll be like, "Ugh." But as regards to when I was actually writing that series, all you're thinking about is making it be the best it can be and just like, "Where are the characters at? Is this what they would be doing and saying at this point?" Thinking of them. And that's the focus, really, is the show.

Do you remember on your last day on the set if there were any particular moments that stood out to you that you're going to remember for a long time?

Yeah. There were two really, really lovely moments where the props guys, Nick Atkinson and Harry Larkin, they gave me a box of certain props from the show, which was completely out of nowhere. And then production, they gave me a book, I've got it down there [gestures behind him] and there's a picture of — everybody from the crew and everybody from the cast all had a page, all the departments, and they all wrote the most unbelievable messages. I really didn't expect that. I didn't know people felt the way that they seem to say they did with the things that they wrote. And that's something I will treasure forever, because I'm absolutely blown away by that.

That's wonderful. Can you give me a sneak peek at any of the props that you mentioned there?

Yeah, where are they? I can get them out. [rustles around and holds up items in front of the camera] I've got ... I don't know if I should have this. My god, I'm probably going to get a call from Apple. I've got identity cards of the Slow Horses. I got Jonathan Pryce's fake passport, some fake money, the tin that River's grandfather buried his flight fund in. Am I confessing to theft here? And then, I got Min's plaque from the church as well.

Amazing.

So we've spoken previously about the way that some people in this show underestimate characters like Catherine and even Lamb to some degree, while River maybe overestimates his own abilities in some ways.

Absolutely.

I think it's safe to say that that idea continues to be explored in this season. And without necessarily giving away any big spoilers or anything, I was just wondering if you could talk a little about the kinds of conversations that you had with Jack Lowden about River's journey over these episodes.

Well, the key thing I remember with Jack was, at the end of four, he was like, "Where does it go in five?" Because four was such a big season for River. And I was like, "Well, it's the fallout. You're undermined by it, you're thrown by it, you're processing it. You're dealing with the fact that your dad tried to kill you and that your dad is a psychopath, and then your grandfather is still alive, [your] hero who has had his halo slightly dented by what you found out about him. So he's declined morally in your eyes, and he's also still mentally and physically declining. So it's River trying to hold everything together and still be the best he can be and still coming up short, but then also saving the day." 

And that's the joy of River. It's the joy of what Mick has created in terms of the tone of those books and what Kadiff Kirwan, who plays Marcus, I have to credit him with it because it's such a great observation, that Jack gets to play the hero and the clown. It's just a wonderful combination. So for me that — again, no spoilers — but there's a moment in episode six where you just feel all his agony. And then there's the final beat that I found really, really moving, the final moment we see River in this series. And again, that was why I like, "Oh, this is a fun place for me to go because I'm leaving River with one idea of his future and the audience has another." And there's a sweet sourness to that. But Jack is incredible. They are all incredible, but the way Jack plays River and the heart he gives him and how much you want him to succeed and you know he is not quite going to and all of that, it's just a beautiful mix.

I have to admit that as I was going into the season, I wondered if the balance might tip by having Roddy Ho be at the center of the story this time. Because sometimes, when you take a supporting person and put them more in the spotlight, you realize that the reason they work so well is because there's just normally a little bit of them in each episode. Obviously Christopher Chung is a great performer, but did you ever worry about upending the balance at all this season?

I didn't, mainly because Mick had done it in the books and I thought it worked so well putting Ho in the center there, and it was just the right moment for him to come forward. And also, because as you say, Chris is so brilliant and I just knew Chris was going to shine and fly. It's such a hard part to play, that, because it could easily be just gross and offensive and unbelievable. And he invests it with such reality. You believe that Roddy believes this stuff. And I think also, because of the way the rest of the cast react to him and play off him, they can't get through to him, he's like a conspiracy theorist. He has these great scenes with Taverner and where she tries to sit him straight about a situation and you can see he just reconfigures it as to why, "Okay, you might be right about that, but you're wrong about this and I'm still the best." It's so maddening.

And this is the thing that Saul Metzstein, our returning director from series three, says about Chris and why it works so well, is he never lets you in on the joke. You look at his eyes and there's no sense that Ho understands he is funny or that he is an object of ridicule. Chris is so committed to that and Chris can so inhabit it to the point where, when we wrapped series one, See-Saw, the production company, gave all the actors a print with a key quote from their character. And the one I chose for Chris's was that, "They tried to lock me up, but you can't cage a dragon." And it was actually a line that Chris improvised in one of the takes, and I wanted him to have that line framed so that he could really feel the ownership of that character and all that he brings to it.

One of the many, many joys of working on "Slow Horses" has been watching Chris just grow and grow and grow and take off with this crazy character. So no, I didn't, and I was always confident as well that the show can move into different territories. And again, it's what Mick does with his books. He's always renewing it and having different villains and people die and come in and out, and he's constantly refreshing it, and I just think you can't do the same thing. "Spook Street" was just phenomenal and it was just so dark and personal and there was so much hurt and pain in it, and you think, "Well, we can't do that again. It'll feel like diminishing returns." And it just feels like a great thing to go in a different direction. You think, "Well, a series where Roddy Ho gets a girlfriend is automatically going to be funnier than a series where David Cartwright has dementia and people are trying to kill him."

But it's still the same show. It's still the same thing. You're graphic equalizing, but it's still got a unity to it across seasons, I think. I hope. Fingers crossed.

I wanted to talk to you about the opening scene of this season, which depicts a mass shooting. And I know there have been bombings and mass casualty events in the show in the past. Often in spy shows, it's easy to look at big events like that as outside your lived experience. Even the shootout in the streets of London in season 4 feels very specific to that story and these characters. But the mass shooting that opens this season involves a bunch of civilians, and because that happens with such depressing frequency in the United States, it feels different to watch that. How did you approach that scene?

That's a really good observation. I hadn't thought of that, but you're completely right because Stansted is enclosed. Dickie Bow in series two is just one person who nobody really knows. And then, Istanbul is its own thing. I suppose it's the bomb at the opening of series four, but that's so deep background, you don't feel that in the way that [the mass shooting] was very visceral. And we did think very carefully about it. The reason we did it, it's in the book, it's the kickoff, so we always want to honor what Mick does and we love what Mick does, so we were always going to do it.

And we did have a version where it cut out as he starts firing, but that felt ... it didn't quite go far enough to ... it just didn't give you enough, but we didn't want it to be horrific or upsetting, so you're staying with the gunman. But that makes it feel even colder and his blankness is just really, really disturbing. Then, you have the moment [when] something happens that you think, "What the hell's this?" But that just felt like a really good twist that the audience don't see coming and are confused in a good way. They're like, "What's happening?" and hopefully they trust that we will explain. So we were very, very mindful of that. And obviously it does echo horrific events in the real world. But again, it feels like a new thing for the show to do, which, it's important the show goes to new areas and it doesn't repeat. That's the main thing.

There was an interview that you did with Deadline where I think they asked you about adapting Mick Herron's "The Secret Hours" as a potential spin-off. Is that something that you're actually interested in adapting for real, or is that just a pie in the sky type of thing?

Both. [laughs] It's not happening. There's no plans to do it, but I would just love to see it. I think it's one of my favorite books of Mick's because it's so inventive and surprising and he just really challenges himself, but not in a way that feels indulgent to the reader. It just feels like "What a great device." He's in the present and people are digging into old files about an incident that happened in Berlin in the '90s, and then you flash back to Berlin and then they pull some of these people in the present to interview them and you gradually realize, "Oh my god, this is Lamb and this is Taverner and this is David and Dickie Bow is here." And it just felt like this wonderful sequel/prequel that explains so much in a really, really inventive way.

I just sort of get off on the idea of the de-aging technology being in such a good place, hopefully, that that wouldn't be an issue. And Gary is such an amazing actor that I'd love to see how he figured out how Lamb moved 20 years earlier and how he spoke. I just think that Gary would just dive into that and would just blow us all away again, in a different way. I just want someone to make it at some point. [laughs] I'm sure they will make all of Mick's books and all the sidebar books and the novellas, I'm sure it will all be put on screen, so I've no doubt that at some point that will happen.

Is there anything in particular that you're going to be eager to watch as a fan, assuming you keep up with the seasons as they go?

Oh, god, yeah, all the books. I've read them all. I'm very lucky that I get to read them slightly in advance of other people. So I know what's coming, and I can't wait to see it. And the cast are amazing, the crew are amazing. It's going to be fabulous. Adam Randall is back to direct series six. He just won an Emmy for series four. He's off the scale, so it's going to be great.

Do you think there's ever a chance you might be able to come back to the show several seasons later and jump back in, or is that not on your radar?

I hadn't really thought of that. I just think it will become someone else's thing and I don't think it's helpful to have anyone on the shoulder or coming in or any kind of ... they have to own it and they have to make it their own thing.

The first episode of "Slow Horses" season 5 is streaming now on Apple TV+, with a new episode coming each week.