‘Slow Horses’ Star Jack Lowden On River’s Season Three Emotional Turmoil, Growing Relationship with Louisa

Apple TV+’s Slow Horses, starring Oscar-winner Gary Oldman, built an audience over its first three seasons and is now firmly in the race for Emmy attention. The British drama series centers around Slough House, an administrative nightmare for spies who failed their more prestigious MI5 assignments but haven’t been sacked yet. They’re meant to endure endless hours of pointless, paper-pushing endeavors designed to crush their spirits. Somehow, they manage to find themselves squarely in the action in defense of the United Kingdom.

Co-star Jack Lowden plays River Cartwright, a man who seems to hold all the right traits for a brilliant MI5 agent but manages to jeopardize that trajectory thanks to a very public mistake. Lowden has been widely praised for his performance with critics hailing his effortless charm. He also thrives when paired with the brilliantly eccentric Oldman.

Here, in an interview with Awards Daily, Lowden details how his character River deals with the emotional impact of season three. He’s still stuck in Slough House, but the season shows that his home life becomes increasingly troubled. He also shares how he views River’s connection with Louisa (Rosalind Eleazar) as one of the show’s biggest highlights. He also raves about the writing team’s adaptability to keep the show fresh.

Finally, for fans of the series, he offers that maybe Lamb doesn’t actually hate River.

Awards Daily: Your character River goes through some major emotional upheaval this last season, especially with his grandfather who is having memory issues, and then River’s actions at the end of the season are going to put more strain on that relationship. What was it like going down that path with your character?

Jack Lowden: It was really wonderful that in something like Slow Horses, which is a dark comedy thriller, it’s quite unexpected that someone involved in espionage has to deal with that. Of course it’s a reality for a lot of people, and spies are human too and they have to deal with something like that. I think it’s a wonderful thing to explore in any way, the inevitability of losing people that you love, and it’s much more heartbreaking to see them disappearing in front of you. So the scenes with him were really quite tough because it’s usually such a fun-filled show in terms of what you get to do. But that’s why I think this show is so brilliant because it’s so multifaceted.

Awards Daily: Continuing with that theme, yours and Rosalind’s character Louisa are teamed up in a way you haven’t really done before on the show. And you guys have that moment in the car where you’re discussing the idea of loss. What was that moment like, and do you think we’ll see more of that dynamic between you two?

Jack Lowden: River and Louisa is something I’m really glad developed because Rose and I have very similar tastes as actors and we get along extremely well and have a similar sense of humor. I was really pleased to see that there was more of that in there. I think they have in a true sense a brother-sister way to them. They have a real openness with one another; they are both incredibly cynical, which fits them down to the ground. She can see through River quite readily, which makes for an interesting place to work from because she hates the job as much as he does. But with River there’s a small glimmer of hope of turning things around whereas she is much more resigned to the fact that she’s going to be there in Slough House forever. I love working with Rose.

Awards Daily: You both get to be in probably the biggest action scene the show has done so far with the shootout in the archive. What was shooting that scene like?

Jack Lowden: That was great! There’s a particular moment with the grenade that was quite fun. The special effects department did such a fantastic job rigging that whole thing up, making it fun but also incredibly safe. The thing I had to get my head around as River was the idea that this was a green on green or blue on blue: that this was our own people firing on us. I love the idea of that happening somewhere that none of us know about. That there is just this internal dispute and people trying to cover things up in the intelligence services. That they’re not fighting any domestic or foreign enemies that they’re supposed to be doing, they’re just fighting amongst themselves. I found that idea quite funny that they’re just in this bunker fighting each other. But to be able to do anything like that is really quite fun, because it’s done with a bunch of humor as well, and not done with such earnestness that you usually see in those kinds of situations.

Awards Daily: You also have the scene of running through MI5’s headquarters, but also having to think on your feet and talk your way around different obstacles, looking like you’re improvising on the spot. What is it like as an actor getting into that kind of rhythm?

Jack Lowden: It’s very unique with this kind of writing, with Will (Smith), the writer, always on set. If there was ever some kind of discovery during a rehearsal or take, I love that they’re open to suggestions. Which is why the show maintains that feeling of improv, as if saying it for the first time. Because Will comes from the background of “The Thick of It,” the writing is very malleable so in those situations that you’re talking about where River is literally trying to bluff his way through the Park it was incredibly useful. One of the great joys of the show is how sharp the writing is, but how willing people are to always take the best ideas . Which I think is essential for something living or dying.

Awards Daily: Do you have any clue what Lamb actually thinks about River?

Jack Lowden: [Laughs] Me personally (which is the romantic in me), I think Lamb knows he’s good, which is why he rides him harder than anyone else. He’s always been pissed off since the beginning because there’s nepotism in that River is the grandson of the former head of MI5, who he doesn’t like. So there is that element. I wouldn’t say that he sees a younger him in River because I cannot imagine Lamb as a 30-year-old man who was too far away from what he is now in his sixties. He just got away with it more because it was edgy and cool instead of washed up and disgusting. I think he recognizes that River has huge potential but he enjoys pulling the rug out from under him as often as possible.

Awards Daily: You have been playing River now for three years and you’ve already filmed the fourth season. Have you thought differently about him as a character since you first started playing him?

Jack Lowden: The reason I wanted to play him so badly was his feeling that the world has turned against him, and the cynicism and sarcasm he has. I do not think that has changed, in fact I think it has gotten more bedded in. I feel River has a reluctant admiration for what the slow horses do, and I think if it came down to it he would partially want to stay there. Because he strangely has more freedom there. They are tasked with doing the most mundane things but they always manage to end up at the forefront of everything. I think if he did get back to the Park and proper MI5 maybe his salary would increase and the rooms you would be in would be more important and nicer but he would miss being there. For me, every time we go back to that Slough House set it begins to feel like a comfy pair of slippers, it’s like going home. It is strangely like your safe space, so it has not changed that much. The storyline with Jonathan Pryce as my grandfather is the thing that’s really changed. It is a wonderful thing to play a character at work who has problems at home. It is a useful thing as an actor that not everything is seen. I really enjoy that.

Awards Daily: You have a lot of upcoming projects. Is there anything about those projects you want to share or anything about season four you can tell us?

Jack Lowden: Yeah, I don’t think I can tell you anything about season four. Someone or something would probably drop out of the ceiling right now if I did that. I can tell you that it was one of my favorites to have shot, it’s very Slow Horses but it is also very mature. The show just feels like it keeps maturing and maturing. In terms of other things, I’ve been doing a lot of things this year. It’s been absolutely manic but in a good way. I finished John Maclean’s film Tornado at the beginning of the year, which is his follow up to Slow West So it is a western set up in Scotland with Tim Roth, which was great fun. I just wrapped on James L. Brooks’ film Ella McCay, which was quite an experience. I’m really excited about that one.