Actor Josh O’Connor says one of the best bits of acting advice he ever received came in the midst of filming Disclosure Day, the latest summer blockbuster from director Steven Spielberg.

In the film, O’Connor plays a cybersecurity expert who gets hold of the government’s proof that aliens are among us and decides the rest of the world has a right to see the evidence. O’Connor wasn’t sure how vulnerable to make the character. Then he received a late-night text from Spielberg, saying: “The door is on the latch, just push.”

“And it unlocked the whole scene for me,” O’Connor says. “It’s like the emotions, just push the door, let it out. And I was like, ‘It’s genius. It’s beautiful. It’s poetical.’”

The next day on set, O’Connor thanked Spielberg for the feedback, and the director admitted that the message had been a misfire: It was an instructional text, meant for his wife as he was headed to bed. “But he killed two birds with one stone, and he doesn’t mind me telling the story. He likes the story, so it’s OK,” O’Connor says.

O’Connor previously starred in the British film God’s Own Country and he won an Emmy Award for his portrayal of Prince Charles in The Crown. Disclosure Day is his first foray into the world of big-budget blockbusters — but he says the experience wasn’t so different from some of the smaller projects he’s worked on.

“The actual day-to-day making of a movie, the collaborative nature of making a movie is pretty much exactly the same. … How do we portray this story in the best possible way?” he says. “[Spielberg] kind of keeps his set small. It feels like a sacred space for performance.”

Interview highlights

On his practice of making a scrapbook for every character he plays

The scrapbook thing comes right back from when I … made God’s Own Country, so it was a good like 12, maybe 12 years ago now. … You could call it a scrapbook or a kind of character Bible, a kind of a manual for how to access this character’s memory. So if you’re struggling with a scene, trying to get into the psychology of this fictional character, it’s like, well, let’s look at the scrapbook. …

I’ve used it for pretty much every character I’ve played since, but the form of this one [for Disclosure Day] was slightly different because we were shooting here in New York and I had an apartment in Manhattan … [with] this huge wall and I just started sketching images. I had this idea that Daniel had a sort of memory somewhere lodged in the kind of recesses of his mind of visions he’d had when he was a child and so these charcoal drawings became a kind of obsession … kind of inspired by the character in Close Encounters — you know, someone who uses art to understand their mind. … I did a lot of that and I put them up on the wall. And then I invited [co-star] Eve Hewson over for dinner to meet her and to chat about the film. And she walked in and she looked so mortified by this quite alarming wall, which looked like a crime scene. And so … I sort of very quickly took that down.

On his portrayal of Prince Charles in the Netflix series The Crown

At the beginning, I had a phone call from my agent saying that they’d like to meet you to play Prince Charles in The Crown, and my initial reaction was no, thank you. … I believe in a more equal society and the construct of a monarchy makes that very difficult. … [Also] I didn’t have an interest in the royal family, didn’t necessarily read much about them. …

But [the series creator] Peter Morgan said this thing to me, which really helped and unlocked a lot for me. He said … “Here is a character who is waiting for his mother to die in order for his life to take meaning.” And that was kind of enough for me to get my teeth into, and then from there it was about constantly coloring everything he does with the same sort of textures that you or I might feel around family, which is: How do you get the respect and the acclaim of your parents? How do we please our parents?

On working on a farm in order to prepare for his role in the 2017 film God’s Own Country

I moved up to Yorkshire in the North of England and I worked on … the farm that we were gonna shoot on. … I had this period where I was just there [and] there were no film cameras, nothing. There was no crew. I was there living and working with John, the farmer. And then at some point, the film crew turn up and I’m no longer his farm hand. I’m an actor. I have a job to do. But that didn’t stop John. … He was like, “Look at these annoying film guys who’ve just taken away my farmhand.” And so there’ll be days where I’d be filming, shooting a scene and then they’d call “Cut,” and John would be sort of waiting at the barn door, kind of a little hacked off that he’d lost his guy, and he was like, “Get back to work.” And so then I’d, you know, birth a lamb and then wash my hands and do another take.

On the grief he feels when a project wraps up

Even when I was a kid doing like school plays, I’d finish the play and my mom would always be like, “You know, he’ll be sick, he will get ill.” And I did, I’d always get ill. Pretty much, without fail, every job I’ve done in my career, I get sick at the end. And I think there is a grief that happens. You have to fall in love with this character, and you have to combine a bit of yourself and a bit of this fiction, and then you live as that character for two, three months, sometimes six months. And then it ends.

Lauren Krenzel and Nico Gonzalez Wisler produced and edited this interview for broadcast. Bridget Bentz and Beth Novey adapted it for the web.