From director John Madden and screenwriter Michelle Ashford, and based on the book by Ben Macintyre, the war drama Operation Mincemeat tells the stranger than fiction real-life story of two intelligence officers, Ewen Montagu (Colin Firth) and Charles Cholmondeley (Matthew Macfadyen), who developed a wild strategy to break Hitler’s grip on Europe and alter the course of World War II. By risking everything and recruiting a dead man to deceive the Nazis into believing troops would land in Greece rather than Sicily in 1943, their game-changing, logic-defying scheme became a mission that ultimately saved tens of thousands of lives.

During this 1-on-1 interview with Collider, Macfadyen talked about making the movie with a fellow Mr. Darcy, working as a peer alongside someone whose career he’s been inspired by, finding the dynamic between Montagu and Cholmondeley, and how the black humor balances out the intense stakes of this wild true story. He also talked about the Season 3 finale of Succession and when he knew the role his character would play in it, as well as working with his wife, Keeley Hawes, on another true story with Stonehouse.

Collider: This movie is fun because the true story of it all just seems so insane.

MATTHEW MACFADYEN: Yeah, it’s bizarre that it’s true. I know.

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Image via Netflix

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Even reading the script, did you keep looking up details to see if they were real?

MACFADYEN: I had the book, I just hadn’t read it. I’m a big fan of Ben Macintyre, who’s written lots of those true stories. It was just delightful because you think, “Wow.”

To ask you a bit of a silly question, when you do a movie that teams you up with a fellow Mr. Darcy, do you share any stories about what that’s like, or is it just an unspoken bond that you have?

MACFADYEN: It’s an unspoken, deep bond, where you don’t speak about it. We just looked at each other. No, we did talk about it a little bit, but not very much. We just giggled about it. And then, we said, “Do you think people will ask us about it, when we have to do the junket?” It’s a funny one. When you play someone who’s famously dishy in literature there’s a bit of pressure. You just think, “Oh, shit.” So, we both laughed about that. Mostly, I just loved making the film with Colin [Firth]. When I was half-forming the idea that I could be an actor, I was watching things that he was in, when I was 14, 15, 16. There’s a film he made called Tumbledown, and another one called A Month in the Country, and I’d seen him on stage. It was really lovely to finally work with him, 30 years later. It was great.

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Image via Netflix

What is it like to work with somebody so closely who you had previously been influenced by, and you had admired his work, but now you’re working with him at a point in your career where your peers? What does that feel like?

MACFADYEN: It feels lovely. It’s just a real pleasure. The nuts and bolts of being on set is the same. We’re both actors, and you do the work. If you get on and have a nice time, then so much the better, and we did. It was a lot of nattering and gossiping. And Colin is great friends with Kelly Macdonald, and I’m friends with her. I’d worked with her before. It was a nice group, with Johnny Flynn and Penelope Wilton and Jason Isaacs, who I knew. It was a really nice atmosphere on set.

When you do something like this, where the dynamic between the characters is so important, some of that is up to the script, but some of that is also up to what the actors bring to the characters and how they play off each other. Was the dynamic between these men something that was very clear on the page? Did you guys have any rehearsals or conversations about it, or did it just feel like it all naturally fell into place?

MACFADYEN: We had a good period of rehearsal. Inevitably, with something like that, you add in bits and pieces. There’s a love triangle, which is confected, dramatically, for the story. That was new, but that was great fun to play. And also, when you’re creating a character, like they were with the fictitious Major, it made sense that they would become invested because they were so imaginatively and emotionally invested in this story, and it bled into real life. That seemed to make great sense, and it was dramatically interesting. Cholmondeley and Montagu, in real life, really liked each other and admired each other, and worked very well together. They were both very bright and creative lateral thinkers, and they were both committed to the war effort. That was great to play. And then, you have the tensions because they’re under great stress and anxiety about whether it’ll work, as the story goes on.

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Image via Netflix

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I was fascinated by how really personal and intimate this story feels, in the middle of such an epic tale going on around them. Did that really help you identify with the story and these characters more? Did it help make it feel more accessible to you, to focus on their personal story?

MACFADYEN: A little bit. There was a lovely bit of backstory for Cholmondeley, with his mother and his glamorous older brother who died fighting. He was the heroic older brother. Cholmondeley had tried to be in the RAF (Royal Air Force) and couldn’t because his eyesight was bad. And he probably couldn’t have fit in the cockpit because he was so tall, and he had great big feet. That was interesting to play. But I think it was so well-written and the stakes are so high that you just have to play the scenes and make sure you’re aware of what’s at stake, I suppose. And in those situations where there is a lot at stake, there’s a lot of black humor, which was great. I believed all of that. Often, when things are very, very tense, people fall about with almost hysterical laughter. There are a lot of digs and a lot of gallows humor, which I think was a nice element to have in the film.

I’m sure you’ve heard this many times by now, but the Season 3 finale of Succession was absolutely brilliant, and your character really played a large role in that.

MACFADYEN: Yeah.

Why do you think he took that moment to betray Shiv so decisively? Was that something you thought a lot about?

MACFADYEN: I don’t know. I don’t know when the moment was. Maybe there was a phone call, when he’s at the wedding and the siblings have gone off to see Logan. Maybe it was then. Often, we don’t know why we make decisions, in real life. You think, “Oh, this is what I’m gonna do. It’s clear to me now.” Maybe Tom has a moment of clarity, and it’s not something that’s premeditated or really thought through. He just goes, “Okay, I’m gonna side with him, and I’m gonna take him,” and Greg comes along and that’s it. But it’s the result of a long accumulation of cuts from Shiv and his brothers-in-law. There have been lots of belittlings and betrayals and mini betrayals.

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Image via Netflix

My first thought after watching that finale was that it was the moment that Tom becomes a real Roy.

MACFADYEN: Yeah. Maybe he has got a spine.

Did you know about that, from the beginning of the season?

MACFADYEN: I did, kind of. I did, in a loose way, but I didn’t know the specifics. I forgot about it, in order not to get disappointed if it didn’t turn up. The writers are doing their thing, and whatever they want to do with us is great, so I didn’t want to get attached to a storyline. Jesse [Armstrong] told me and it was wonderful, but then I tried to forget about it. You can’t play that either, otherwise you’ll become stuck. So, I really didn’t know what would happen, or how dramatic it would be, or what form it would take, until I read episode nine, which was right at the end of Season 3.

It sounds like you’re also doing another wild-sounding real-life story with Stonehouse, and you’re working with your wife, Keeley Hawes, on that, playing a couple.

MACFADYEN: We’re playing husband and wife, yeah.

Had you been looking for something you could work together on? Did you guys just get lucky with that?

MACFADYEN: It fell into my lap, and Keeley knew the lovely producer, Ruth Kenley-Letts. They’re great friends, and they’ve worked together a lot, and Ruth said, “Wouldn’t it be great, if we could get Keeley to do this.” And I said, “Well, ask her.” It came together, and it was a really joyful thing. It was great. It might have been a nightmare. You never know. We met on set, and we’ve worked together, but you never know. But it was an absolute treat. It was really good. It was great fun. I didn’t want that job to end. It was a really happy job. That’s another insane story, which is true. You wouldn’t believe it, if it wasn’t written down.

Operation Mincemeat is available to stream on Netflix on May 11th.