Ant-Man and the Wasp: Quantumania’s Kathryn Newton learned to trust the Marvel process in MCU debut

Joining the Marvel Cinematic Universe is a bit like enlisting in the military – you get the chance to become a hero and serve your country (or in this case Hollywood), but once you’re in, you might be in for life. At 26 years old, Kathryn Newton is making the leap, though, with her eyes wide open.

The Orlando-born actress, best known until now for her roles in HBO’s Big Little Lies and 2020′s body-swap horror comedy Freaky, is being positioned as the next generation of MCU superhero thanks to her co-starring role in Ant-Man and the Wasp: Quantumania. Playing Cassie Lang, the 18-year-old whiz kid daughter of the pint-sized Avenger Scott Lang (Paul Rudd), Newton gets to engage in all manner of cosplaying shenanigans as her on-screen family is zapped into the subatomic universe known as the Quantum Realm.

Cassie is so integral to the proceedings that Newton is already a near-lock to appear in the next Avengers movies, 2025′s The Kang Dynasty and 2026′s Secret Wars, and Thanos knows how many other potential MCU spin-offs, sequels, and Disney+ one-offs. So what does locking in your foreseeable future to one megafranchise mean for a career? Ahead of Quantumania’s release Friday, Newton stopped for a promotional tour in Toronto to talk with The Globe and Mail about the power of the MCU machine.

How does it feel to be a part of the MCU machine? I mean, this is a big commitment. Is there a part of you that, after signing, goes, well, my next decade is gone?

The only thing that went through my head is: I’m so ready. This is something that I’ve always dreamt of and kept in my back pocket since I saw the first Iron Man movie at eight years old with my dad. I told him then that I wanted to be Marvel’s biggest hero of all time, and I secretly told myself that if I don’t do this by age 25, I should get another career.

What does your dad think today?

He’s just my dad, so he’s like, “Oh, that’s pretty cool.” He doesn’t care like I care, but he’s proud of me.

What’s the level of improvisation or spontaneity allowed on this kind of movie? How much room is there for actors to play around?

Taking it back to the machine, it was so different than what I thought it was going to be. I thought I’d come to work, say my lines, look at the green-screen tennis ball in front of me pretending that it was an alien, and that’s how it’s going to be. A machine. But it was the complete opposite. [Director Peyton Reed] told me the story was about a girl and her dad reconnecting, and when I got the script, it felt like it was written for me.

Did you get that script under lock and key? I ask because spoilers are so integral to how the MCU operates. How careful do you have to be with spilling secrets – are you worried about being the next Tom Holland?

People call me Tom already now because I let them slip. But my motto is now: Say less. And things are always changing. So much of this movie was improvised – not because we used it, but because Peyton wanted us to play and have an energy that the audience could feel.

The design of the movie’s poster references Joe Dante’s Innerspace, a classic of the, well, shrinking-people genre. Did Peyton talk about his influences, or give you a syllabus of sorts to prepare?

He did, and I can’t remember off the top of my head, but mostly we went off the page. These Marvel movies are weird – you have to trust the machine. Because one day I’d be on set and Paul and I are looking at nothing, and I’m looking at Paul, and he’s looking back at me, and we’re both going, “Are we doing this right?” The point being that you have to let go and not hold back and trust the Marvel process.

So when you’re on that soundstage, it’s like looking at a tennis ball on a stick pretending it’s some fantastical creature?

Some scenes I would have to act with a tennis ball, but most of the movie Paul and I were on a practical set, which is amazing because the lighting is the same and you’re seeing something better than a tennis ball. Sometimes I couldn’t keep it together, because I’d be acting against a regular person like you or me in a grey suit who was acting like a weird little alien dude, making weird gargling noises and I was supposed to be terrified. But really I had Paul next to me whispering, “Don’t laugh, don’t laugh, don’t laugh.”

This interview has been condensed and edited