Cillian Murphy, Emily Blunt, and Robert Downey Jr. call themselves the “OppenHomies.” That’s the group chat where members of the Oppenheimer cast used to trade gossip, insults, and strategic communiques when not together on set, and where they chat now when not reunited at awards events. Filmmaker Christopher Nolan, however, is not included in this special club. Not because he’s the director and, therefore, their boss, but for a practical reason: “He doesn’t have a phone,” Blunt explains.

In Vanity Fair’s video oral history of Oppenheimer, none of the three stars hold back—ribbing Nolan for his idiosyncrasies while hailing how he tackled this sprawling historical epic. The trio spoke on the afternoon immediately after Oppenheimer dominated at the Golden Globes, and each of them remains in the Oscar hunt. Murphy stars as Oppenheimer, the stoic physicist who became known as the father of the atomic bomb. Blunt plays his staunchly protective wife, Kitty, while Downey plays his political nemesis, the calculating Atomic Energy Commission bureaucrat Lewis Strauss.

Yes, many of the rumors about Nolan’s sets are true. The director doesn’t allow extra chairs in the vicinity of filming, to literally keep his actors on their toes. There’s no lounging, no trailers where they can retreat. Phones aren’t allowed either. “If I see Chris Nolan, I throw my phone,” Downey says.

“Still—to this day!” Blunt agrees.

That forced focus led these actors to their most intense and acclaimed work; it also bonded them as well. “He’s not like one of those dads that you’re afraid of,” says Downey. “It’s more like…to have the word ‘disappointed’ uttered would be the most crushing blow.”

Murphy—who has worked with Nolan on Dunkirk, Inception, and all three films in his Batman Dark Knight trilogy—relates the unusual way the filmmaker draws an actor into a project. “He flies wherever you are and gives you the actual script himself in person. And it’s always printed on red paper with black ink. And [Oppenheimer] was a tome. It was a door stopper of a thing,” he says.

Why the strangely colored pages? “I think it’s to prevent against photocopying,” Murphy says. “Because Chris probably does possess a photocopier.”

“And a fax,” Blunt adds.

Downey confesses that Nolan made him drive to Nolan’s house in Los Angeles to read the script—which is how Downey’s wife knew that was going to say yes to the role of Lewis Strauss. “Unlike these two sycophants, my first reaction was, ‘I’m not going east of La Brea,’” Downey jokes. “I was told [by my team], ‘If this is your opening salvo, we can’t help you with the rest of your career.’ And I said, ‘All right, how far east of La Brea?’”

Switching to earnest mode, Downey acknowledges that even for seasoned veterans like him, getting asked to do a Nolan film is a unique compliment. “It is kind of an event just to get the call,” he says.

“And private, in a lovely way,” adds Blunt. “Usually everyone’s in the know, and your agents and your team, and all the producers know, and that’s being discussed by people. There’s sort of the chatter and the noise around putting a project together. This feels really distinctive and calm and private and peaceful.”

“And reasonable,” Murphy says. “The thing I should say as well is that every time Chris has called me, I’ve always said yes before I’ve read the script. So it’s just a formality, really, reading the script.”

“Can we pause for a second?” Downey says. “He calls you for the title character—and even just those four syllables together, you go, ‘Wow, this is heady stuff. This is important stuff.’ And he’s come to Dublin, so this is not the youzhe. [That’s Downey-speak for “usual.”] I’m sure he didn’t come to Dublin for your four days on Dunkirk.”

Then Downey catches himself: “Or did he?”

Murphy mulls it a moment and says, “I think his mom dropped me the script for Dunkirk…”

“Oh, God, stop it,” Blunt groans in response to Murphy’s obvious “favored nation” status.

“But seriously, you realized this is for the lead in this. It’s kind of like his whole career has been leading to this film, both yours and his,” Downey says to Murphy.

“I believe so. Certainly for Chris,” Murphy answers. “It was huge. Before I had actually read it, when we discussed it on the phone, I knew it was a huge part.”

Was the project more intimidating before or after he read it? “It didn't get any less intimidating,” Murphy says. “It remained. But in a great way. I’ve always said this: I need to feel intimidated by work. It needs to feel dangerous or impossible for me. If it feels like I know how to play that, I’m not really interested. It needs to feel like a huge leap. And this was one of the biggest leaps for me.”

Blunt and Downey felt the same pressure, which they agreed isn’t a bad motivator. “I like the feeling of mild terror too,” Blunt says. “When something feels out of reach or a bit remote to you at the beginning, and yet you’re going to have to put your feet to the fire in some way—I love that and want that. I think the huge comfort is getting to play that kind of role in a Chris Nolan movie because you’re safe. You’re safe to do whatever you want to do.”

“And Blunt is known for thriving in intense circumstances,” Downey begins, but he's interrupted when Blunt can’t hold back a laugh. Downey goes silent as she points a wary finger at him. 

“I thought you were about to throw me under the bus,” she says, braced for a wisecrack from the Iron Man actor. “He does this to me all the time. He will drop in these little tidbits of information about me that are not true. But you were about to say something nice. Keep going, continue.”

Downey begins again: “Well, knowing that she was just recently taken off parole, I felt that it would be a great opportunity for her to spread her wings…”

Despite the intensity and commitment necessary for their own roles, Blunt and Downey both say that as supporting players, they felt fortunate to “jet-pack in” to the movie—while Murphy was burdened with carrying the sprawling film, which was shot over 57 days. 

“It’s a butch thing to do, dude, because you want to explode,” Downey says. “I’ve heard directors like Peter Weir say—at every point directing a great actor in a film, he’s seen it when they lost it. [Oppenheimer] is a character and a time and a situation and a project where to lose it would be to lose everyone. It was a demonstration of principle like I’ve never seen.”

Murphy remains humble. “I could not believe the level of actor that Chris had got for each part,” he says in response. “It was just mind-blowing. And so I did feel so carried and held by these guys every single day, by every single one of them. There was real love amongst us all. I know that sounds cliché, and such an actorly thing to say, but it actually was the case. It was real compassion from these guys that I felt every single day. And then, of course, it's just the quality of their skills. You come into a scene with either of these guys and [the performance] just steps up immediately.”

When Downey is asked if he felt similar pressures when he was the center of a vast, historical biographical drama as the lead in 1992’s Chaplin, it’s his turn to be modest. “I didn’t have the benefit of being a mature human, as you were,” Downey tells Murphy. “So I wasn’t able to bring—really bring—what you brought.”

“To be put in the same sentence as that movie is good enough for me,” Murphy says.

“Okay, that movie didn’t sweep the Globes,” Downey interjects. “Anyway…”