The former Billy Elliot star adds a new meaning to the phrase “brick house” as The Thing in Fantastic Four.

It sounds like a joke at first: “starring Jamie Bell as The Thing”. The ballet boy from Billy Elliot? The spry young Geordie with the slim shoulders? Mr Bell’s a slight 5’ 7”, perfectly constructed for a demi-plié or pirouette. But punching through walls and yelling, “It’s clobbering time”?

“That’s what I said when they offered me the part,” he laughs. “You can’t be serious. I mean, look at me!”

Mr Bell is not very Thing-like. Business-like, perhaps. He’s just flown in to LA from New Zealand where he’s been shooting 6 Days, a movie about the Iranian Embassy siege in London in 1980. (“Hence the burners,” he grins, rubbing his sideburns.) With that, and his AMC series Turn and now press for Fantastic Four, the fatigue is setting in. He had a car take him to the shoot today, at a beautiful Richard Neutra house near Silver Lake Reservoir. “I should have walked,” he says. “I only live down the road.”

Casting Mr Bell as The Thing was an unexpected move by Fantastic Four director Mr Josh Trank, best known for his 2012 indie superhero hit Chronicle. But that, says Mr Bell, is what Mr Trank was going for. “Unexpected cast. Unexpected tone. You know, surprise people,” says Mr Bell. “We talked on the phone for two hours, and that was it. Next thing I know, I’m in the middle of Louisiana in a motion-capture suit, on stilts.”

Fantastic Four isn’t Mr Bell’s first blockbuster. He made The Adventures of Tintin with Steven Spielberg in 2011, another motion-capture deal. As a former dancer, he’s well equipped for this kind of work – it’s all about movement. “I watched a lot of wrestlers and heavyweight boxers, the way they would move and sit,” he says. He holds his arms out like brackets to demonstrate, elbows bent, shoulders sloping.

It was an odd experience, all in all. Mr Bell would show up in his pyjamas, get up on stilts and perform the same movements over and over again.

“Blockbusters are these gargantuan, slow-moving creatures,” he says. “We filmed a scene of us literally getting out of a teleportation pod and taking a few steps. It took three days. You get lackadaisical. What are we doing? Oh yeah. Getting out of the pod again.”

He was living in a mall at the time, above a J.Crew store (there aren’t that many hotel options in Baton Rouge, Louisiana). “It was nothing short of incredibly depressing,” he says cheerfully. “Totally impersonal. You’re living in ‘buy, buy, buy’ the whole time. So, of course, I accumulated a ton of shit I don’t need. Before I went home, I had to buy another suitcase to carry it all.”

Mr Bell regards blockbusters as a career move. “You get to work with good directors and good actors because, you know, everyone wants to be in these movies,” he says. “And obviously, being in a big film helps when it comes to making other things and moving forward with your career. You get this illusory kudos just by association with a project like this, so studios support you and put you in stuff. It sounds superficial, but it’s important.” He shrugs. “And obviously you’re well taken care of.”

It’s understandable that Mr Bell is feeling a little pragmatic. He is a father now, to a two-year-old son with the actress Ms Evan Rachel Wood (the two split amicably in 2014 after a 19-month marriage). Mr Bell never knew his father, who left before he was born. “Raising a kid is difficult,” he says. “But those aren’t my principles. I don’t really run away from things.”

In fact, growing up fatherless, he says, has helped him now that he has a boy of his own. “I was raised by women, my grandmother especially, so I think the nurturing side of me is a bit more profound than it would be if I just had two parents.”

One of the oddities of Mr Bell’s career is that many of his previous roles have resonated with his own experiences in an uncanny way. He’s played several characters who are missing a parent (including the titular character in Hallam Foe and Chris Munn in Undertow), while his breakout movie Billy Elliot might have been a documentary of his youth as a ballet dancer in the north-eastern town of Billingham.

But Mr Bell has been seeking increasingly adventurous and far-reaching material. He’s 29, at the peak of his powers, and his hunger to improve is plain. He’s a thinker and observer, who likes to walk the streets or ride the subway and just watch people. “A lot of the time I think if I did what that person just did on a film, the director would be like, ‘That’s ridiculous. It’s too much.’ Just random physical gestures, the way people try to cover their embarrassment, or the way they walk.”

These musings have resulted in roles such a K, a sinister male dominatrix in Mr Lars Von Trier’s Nymphomaniac Volume II. This, evidently, was more of a stretch for Mr Bell. “I don’t practise those things in my personal life,” he says, laughing. Then there’s The Thing, a creature with rock-like skin and (in previous outings of the franchise) a thick New York accent. Playing characters like these has tapped in to Mr Bell’s preference for anonymity, something he exercises when it comes to his personal life. “You don’t really know anything about him,” he says of K. “My characters hide behind rocks, or quiffs and dogs. You don’t see my face. My voice is modulated. I like it that way.”