Can you introduce us to Lethal White?

Lethal White is the fourth book. It picks up pretty much where Career Of Evil left off, some months on. It’s an interesting point in their relationship.

In the book, the first murder doesn’t occur until about 200 pages in, but there’s an awful lot of other stuff going on. There’s a cold case that is alluded to. In fact, it was never a case; there’s a murder that is alleged to have happened, and they’re trying to get to the bottom of it. In a very noir-ish way, two different cases start to overlap each other. It’s also set in the world of politics.

Did you have to do any extra research into the worlds of LW, beyond the script and the book itself?

No. I think the research thing is always a delicate balance. I did a lot of research into surveillance when we filmed the first books, and I’ve got a very good friend who’s a plain-clothed policeman. But because the whole show flirts with genre, the way we tell the story has just as much to do with The Big Sleep or Chinatown as it does with the reality of the thing.

You know Cormoran well by now. As we learn new things about him, how do you continue to approach the way his character develops?

I think this [book] goes into more depth about certain things than we’ve seen before, especially his relationship with Charlotte. It’s not immediately obvious why somebody like Strike would get so caught up with somebody like Charlotte. But I suspect a lot of his behaviour is to do with a kind of comfort or insulation - he likes his stodgy food, his beer, and he’s had this strange, painful childhood which is still a raw nerve. His relationship with Charlotte is like somebody willfully running towards pain. What’s going on there? I think some part of him must want that.

I talked to Jo and Natasha about it, and the main thing we came away with, is this idea that Strike and Charlotte are connected, somehow, bonded by a sense of being outsiders in their own family. And that could bring people together in a powerful way.

In terms of Strike’s other significant relationships, including with Lorelei in LW, what do these show us about Strike and his relationships with women?

I think you get a sense, certainly in the books, that whatever else Strike’s and Charlotte’s relationship was, they were very sexually compatible. And I think the same goes for his relationship with Lorelei too. She’s a genuinely kind, decent, and interesting person. But as somebody who doesn’t have the simplest life, or the simplest job, I think having that degree of immediacy is something he craves, however much there might be a question mark about him and Robin.

Can you talk about how far Strike’s relationship with Robin has come?

I had a sense of Strike being, emotionally, one layer of skin thinner in this one. There's this beat, this moment that happens near the beginning, which the book frequently returns to. It’s at Robin and Matthew’s wedding. Robin and Strike don’t quite know what’s happened, only that something has happened, and both of them carry that throughout the four episodes. They’re a little awkward with each other at times, not quite knowing how to get back to where they were before. They don’t quite understand what they’re doing or where they’re going.

I think a lot of LW is them having to just get on with it. It has quite a strong procedural element to it.

Can you talk about the tension that exists between Strike and Matthew?

One of the scenes that people seemed to talk about in The Silkworm was the pub scene with the three of us. I hope we get a repeat of that. Matthew and Strike have about three lines between each other in Lethal White, passing in a corridor. So in a way, in terms of what we see, it hasn’t developed much at all.

I think one of the reasons that the pub scene was so fun to play was that, despite the clear and palpable tension, everyone was pretending there wasn’t any, and all those things that the English do so well. I think they call it denial.

Can you talk about the fact that Strike being a modern-day, contemporary detective, is nevertheless using very few modern detective techniques in his work? Does this contribute to his appeal?

I’d just like to preface this answer by saying that while I don’t think that’s entirely true, I do understand why it's come about. Michael Keillor, who directed The Cuckoo’s Calling, said in an interview that Strike is an analogue man living in a digital age. This then got quoted back to me during an interview, and I said something like, "Oh yeah, I guess he is" - without really knowing what that was. But, as an example, there was a time when I was taking photos in Lula Landry’s apartment, using a camera rather than a camera phone.

That was a choice, but we moved away from it quite quickly. I think not having a smartphone, especially in Strike’s profession, wouldn’t just be swimming against the tide but also an affectation. But I guess where Michael and I were definitely on the same page is that Strike is slightly out of his time, at odds with his surroundings. When we see wide shots of him walking down the street, there’s just something about him - he doesn’t quite blend in. So, the reality is that of course, he’d have a smartphone - he just wouldn’t have any apps.

I think there’s something about the detective genre as a whole, with its roots in the gothic or something. Still, they often have something almost existential to them, and pretty much all detective stories place their heroes slightly outside of the worlds they inhabit.

In terms of his physical disability and his inadequacy in dealing with it, has that become second nature now with playing Strike?

Well, his lack of self-care is always useful to me in terms of knowing where he’s at. It’s a gauge now, whether he’s taking care of himself or not - a kind of barometer. In terms of me portraying the condition, there are certain things that are less of an intellectual exercise now, like how I’m going up or down stairs. But I’m slightly suspicious about getting too used to it as I think it’s important to remember that I’m not in pain, me, so it's always going to require an imaginative leap.

We feel that Charlotte is going to continue to be a part of the story for Strike. How do you see that relationship and that role playing out?

I don’t know how it will pan out, but I do think she will be in it a lot more, and I think that’ll be interesting. It’s a kind of a challenge; it has to feel like it will make sense. Without trying to explain it, you have to establish what their currency is to each other. I’m very much looking forward to that.

What makes Strike stand out from other detective shows?

I’m not sure that’s for me to say. But the relationship, Robin and Strike’s, seems to me to be the heart of the show.

Again, I feel I owe a lot to my forebears, the detectives I greatly enjoy watching, or the portrayals of detectives I greatly enjoy watching. Sometimes one feels that they balance moral imperative with a kind of obsessive need to try to understand evil. I think that Strike needs to understand it because of his history. I like the fact that he always seems to think he’s got the measure of the killer and why they’ve done it.

He’s brilliant at working it out. They both are, together. He always seems to think that, if he sits somebody down and says, listen, I know what you did and why you did it, that they’ll almost breathe a sigh of relief, as if he were a sort of older brother figure. They either tend to run away or hit him over the head with a bottle. He’s not a brilliant judge. Or he’s trusting. There’s optimism there because he’s trying to understand. At the heart of his vocation, at the heart of him, is a need to understand.

I think if somebody is threatening somebody he loves, it becomes very personal and he’ll wallop them. Otherwise, there is a strange detachment.

What do you think the future holds for Strike and Robin?

I don’t know. Not in real life, of course, but I’m quite a fan of catastrophe. I’d quite like things to go very, very wrong. But I don’t know - we’ll see.