Married spies with secrets? After Cate Blanchett and Michael Fassbender’s recent demanding roles, that’s almost a vacation

It’s taken a few false starts to get Cate Blanchett and Michael Fassbender on the same Zoom call. She’s been preparing to open a production of “The Seagull” at the Barbican in London, her first time onstage since 2019. He’s been on a much-needed holiday with his family before returning home to Lisbon. Perhaps that’s why, in an hour that finally aligns with everyone’s schedule, it feels genuinely miraculous to hear the two actors share stories of their craft.

There’s a lighthearted moment of catching up between them, reuniting after shooting Steven Soderbergh’s spy thriller “Black Bag” last spring. Fassbender wants to know how she feels about the play’s opening night (a bit nervous), and Blanchett is curious if he wrapped his series “The Agency” (yes, in December). They have an easy shorthand that suggests a long history. But in truth, they only shared a handful of encounters before making “Black Bag.”

They recall meeting at various awards shows in 2014, when Fassbender was Oscar-nominated as a supporting actor in Steve McQueen’s “12 Years a Slave” and Blanchett won the lead actress award for Woody Allen’s “Blue Jasmine.” A few years later, they were on set in Austin, Texas, for Terrence Malick’s elliptical 2017 drama “Song to Song.”

“We actually did a scene together in that,” Fassbender remembers.

“If you can call it that,” Blanchett cracks. She’s sparky but focused as she sits in her home office. “I don’t think it made the film. I don’t think anything I did in that movie ever made the film. It was in that phase where Terry, having come off the back of making one film a decade, made three or four in a row.”

“He literally did ‘Knight of Cups’ and then straight into ‘Song to Song,’” Fassbender recalls, speaking from what appears to be a very ornate living room with tall ceilings, before asking Blanchett, “Did you do ‘Knight of Cups’ as well?”

“I did,” she affirms. “But likewise I don’t know whether anything I did was in the movie. But that’s the contract, isn’t it?”

Not so with their current director, Soderbergh, whose efficiency and command are legendary. “You know that when you work with him, absolutely everything you shoot will be in it,” Blanchett says, with a sense of pride. She grins, adding, “And, in fact, he’s already shot and edited the thing before any of us have shown up.”

In “Black Bag,” Blanchett and Fassbender play a married couple who are both high-level spies in the British government. Soderbergh and Blanchett had been planning to collaborate on a different film, but when that didn’t come to fruition, the director pivoted to screenwriter David Koepp’s wry, unconventional take on an espionage story. He and Koepp had previously collaborated on “Kimi” and the ghost story “Presence,” and Soderbergh liked that the script had broad appeal.

“It’s hard to find things that are commercial that are also really good,” Soderbergh told me in London earlier this year. “And it had certain challenges in it that were of concern, and I wanted to see if I could pull that off.”

There’s a memorable intensity to the filmmaker that can sometimes feel remote. Blanchett admits that, initially, she was “absolutely terrified” of him.

“He was an enigma,” Blanchett says of making 2006’s “The Good German.” “He was totally present, but I had no idea how to communicate with him. After that experience, we got to know one another.”

She compares him to a peregrine falcon because “his frame rate operates at an entirely different speed to everybody else’s.”

“He is like a sharp-sighted bird,” Fassbender agrees. “When he walks into a room, he clocks everything.”

“You can’t replicate him,” Blanchett says. “I’ve worked with directors who have tried to imitate that relaxed quality that Steven has on set, but he is like a coiled spring. He’ll cut people off midconversation and just start shooting. He’s always ready.”

“Black Bag” undercuts traditional spy films by swapping out action in favor of dialogue, notably in the form of two extended dinner party scenes. In the film, Fassbender’s character George Woodhouse is tasked with investigating a mole in the U.K.’s National Cyber Security Centre. He has five suspects, including his elusive, elegant wife, Kathryn St. Jean (Blanchett), one of the organization’s top agents. Both dinner parties are part of an attempt to elicit the truth.

“I wanted to see if I could get away with a 14-page dinner scene because that’s not supposed to work,” says Koepp, speaking over the phone later from New York. “You’re not supposed to have six people sitting at a table and have it build and erupt and hold your attention. I was trying not to do spy-movie tropes, so rather than a car chase before something explodes, I wanted the climax of the movie to be another dinner at the same table.”

Soderbergh was admittedly daunted but also enticed by the puzzle being presented. “If you ask any director, ‘What’s your least favorite kind of scene to shoot?’ I guarantee you ‘dinner table’ is going to be right at the top of the survey,” he says. “So I thought, ‘Can I come up with a way to execute this in which I’m invisible to the audience but the scene is still moving?’”

Usually, Blanchett says, Soderbergh likes to have long restaurant meals with his cast ahead of shooting. This time, she and Fassbender only joined him for one.

“I think because he knew he was going to be filming dinner scenes, it was making him anxious,” Blanchett deadpans. “His blood pressure was going up.”

“We should have gone out paintballing or something,” Fassbender suggests.

“Next time,” she agrees. “He always has to have an impossible challenge for himself as a filmmaker. He loves to not know how to do something. He doesn’t like it to be easy for himself, which is counterintuitive to the atmospheres that he creates on set, which is so relaxed.”

Typically, Soderbergh doesn’t invite his cast to rehearse. He puts his trust in the casting process and empowers the actors to get the job done. But these dinner table sequences were blocked ahead of time because of the technical challenges — which led Soderbergh to take out the middle of the dining table and get inside the hole with the camera.

“We did rehearse those, but it was for him, really,” Fassbender explains, himself a veteran of the filmmaker’s process from 2011’s thriller “Haywire.” “What’s kind of terrifying about Steven, which I had forgotten, is you do one take and he’s like, OK, moving on.’ And you’re like, ‘Wait a minute!’ He gives a lot of trust to everybody.”

Unsurprisingly, the dinner table scenes are taut and dynamic. The camera moves between characters rapidly, resulting in a sense of excitement and unease, and the climatic revelation of the mole is genuinely thrilling. It’s no wonder the actors enjoyed the experience of making “Black Bag” so much, particularly coming off such demanding films as “Tár” and Fassbender’s “The Killer” for David Fincher.

“The thing with working on film is that you’re always full of regret,” Blanchett acknowledges. Fassbender nods his head: “The drive home,” he says.

Blanchett continues, “But with Steven, he always keeps the sets open, so if he goes home at the end of the night and looks at the edit and realizes he didn’t get a shot, or we need another line, or a character needs an extra beat, we can go back and do it. You don’t necessarily get that time up front, but he considers all of it as he’s moving through the thing, which is really fascinating.”

Koepp conceived “Black Bag” while writing the first “Mission: Impossible” film in the mid-’90s. During his research, he interviewed several CIA advisors about their careers and personal lives.

“I was struck that many of them felt like it’s really hard to maintain a relationship when you lie for a living,” Koepp recalls. “I carried that in the back of my mind for quite some time. Marriage is the ultimate trust institution. Those of us who are in long-term marriages feel like: This is settled and this is safe. I wanted to do something where there was suspicion and unease but not about whether the person is cheating or not. It’s about whether they are betraying their country or not.”

Although very little of Kathryn and George’s backstory is revealed in the film, they have an unbreakable bond and a clear attraction. They skillfully navigate between their relationship and their jobs — if there’s anything the other can’t know, it goes in a metaphorical “black bag.” That trust is shaken, though, when George begins to suspect Kathryn’s activities.

“Part of what people find interesting about spies, particularly spies in cinema, is their interiority,” Blanchett says. “That tightrope walk between a deep morality and operating in a totally amoral space. And in a marriage, there are secrets. You do protect your partner from things. There has to be, in order for a relationship to last.”

“They’re constantly operating from a paranoid perspective on things, which is what keeps them alive and keeps them in the job,” Fassbender adds. “Even in the department they work in, you have to keep an eye over your shoulder. A sociopath does pretty well in this environment, but you don’t want too many sociopaths in the same department.”

“Black Bag” is Fassbender’s second time playing a spy during the last year. On the series “The Agency,” from Paramount+ with Showtime, he portrays hardened CIA agent Martian, who is working in London after a long deep-cover assignment. Both projects were offered to him within days of each other, although the similarity was not intentional.

“I’m just doing spies now,” Fassbender jokes. Blanchett, his perfect audience, laughs. He quips, “I just love lying to everyone.” Still, the actor was able to find specifics to “Black Bag’s” George that differed from Martian. It helped that Soderbergh approached the genre with notable warmth.

“The depressiveness of that job, which you can see in a lot of spy movies, is not there on the screen,” Fassbender says. “It looks sexy. It’s slick. That’s a very smart thing he’s done for this particular story. Usually there’s loneliness and isolation when you see spies who have been through a career for 25 years.”

“There’s a lot of chutzpah in being a spy,” says Blanchett. “They’re very serious people, but they’re also so much fun. They can’t have boundaries because they don’t know when they’re going to have to cross them. There’s a fluidity to them, but that fluidity is just masking an enormous amount of damage.”

Soderbergh’s speedy filmmaking style allowed the actors to discover moments together on set, which they both enjoyed. Blanchett describes the director as “incredibly precise, but there’s a flow to him.”

“He’s totally able to pivot,” she says. “Sometimes you can overthink things. I used to think, coming from the theater, that if you have all the time in the world, you’ll get the perfect moment. And then you just string those perfect moments together. A lot of films, they have all the money and time in the world, and all the life gets leeched out of them, which is not the case for Steven.”

“Restriction sometimes brings freedom,” Fassbender notes.

“Yeah,” Blanchett agrees. “Although you don’t want to say that to too many studio heads.”

How do they deal with the pressure that still comes, even with all their years of experience?

“We both get into cold water in the morning,” Blanchett says. She means this literally: On set during “Black Bag,” the two discovered that each begins their day with an ice bath as a way of building focus. Blanchett even took her family to the Arctic Circle over New Year’s and they all leapt into a fjord.

“I’ll give you the details,” she tells Fassbender, like she’s sharing a state secret, “It was really special.”

Her conspiratorial air vanishes as the hour comes to an end and her focus shifts back to “The Seagull.” Like spies, actors know how to adapt as they go.