The star of Broadway’s <i>American Psycho – The Musical</i> demonstrates his killer way with a bar of soap and an electric toothbrush.

Mr Benjamin Walker, star of the new Broadway show American Psycho – The Musical, is pacing a downtown New York City apartment. It’s a big loft, expensively masculine with low-slung modern furniture and muted animal hides draped just so – and it definitely does not belong to Mr Walker.

It’s been hired for the shoot, which explains why one of Broadway’s hottest stars is padding around the kitchen in his socks. These are strict house rules. The slice of apple that Mr Walker is eating may not go into the living area, and the marble counters must be treated with utmost delicacy. A pre-shoot memo also instructs paying guests to “bring your own floor protection” and leave the stereo the hell alone. No Genesis, no Huey Lewis And The News.

The privileged uptightness of it all is somewhat reminiscent of Patrick Bateman, the Wall Street serial killer at the centre of American Psycho. But maybe it’s not that crazy a coincidence. This is Manhattan. There are would-be Batemans lurking everywhere, and not just on Halloween, when there seems to be at least one guy in a suit and a transparent raincoat at every party. “New York today is American Psycho on steroids,” Mr Bret Easton Ellis, the novel’s author, declared recently. Divisive upon publication in 1991 and adapted almost a decade later into a film that became a cult classic and helped launch Mr Christian Bale in the process, Mr Ellis’ blood-spattered satire of Reagan-era excess is now a global phenomenon. It has survived – indeed, surpassed – the 1980s much in the manner of Bateman’s idol, Mr Donald Trump.

Mr Walker, a natural jokester with a fireman’s jaw, is the face of its next chapter as Bateman returns to his original hunting ground of New York. (The behind-the-curtain talent includes Tony Award-winning composer Mr Duncan Sheik, artistic director Mr Rupert Goold, writer Mr Roberto Aguirre-Sacasa and the in-demand set designer Ms Es Devlin. MR PORTER is once again providing the wardrobe for the male cast, just as we did for the original London production, starring British actor Mr Matt Smith.) Mr Walker’s portrayal is slightly more sympathetic than Mr Bale’s, partly due to the fact that he sings and dances to electro-pop that isn’t afraid to rhyme “mahi-mahi” with “Isaac Mizrahi”. But Mr Walker, like the rest of the production, also brings Bateman’s frustrations – with his own depraved proclivities, with his money-obsessed milieu – to the surface. And, reactions have shown, the humour. “I’m surprised at how funny people find it,” Mr Walker admits.

At the same time, however, Mr Walker clearly relishes playing a monster, especially one who narrates aloud his favourite fashion labels and sickest thoughts. He loves that an audience member hissed at him during a recent preview performance. And he views mobile phone interruptions as an opportunity to amp up the horror-camp: “I mean, I just cut a man’s head off with an axe! What do you think I’m going to do to you if your phone rings again?”

Part of Mr Walker’s scariness as Bateman is physical. He’s sculpted his back and shoulders to terrifying perfection for the role, which requires him to enter the stage on a tanning bed. (See Mr Walker’s fitness regime.) It’s not the first time he has stripped down in the name of art, or played with a potentially uncomfortable mix of elements. He did both in Bloody Bloody Andrew Jackson, the gleefully anachronistic rock musical that made Mr Walker a breakout theatre star in 2008. That led, for almost obvious reasons, to 2012 film Abraham Lincoln: Vampire Hunter. Clearly, he has the lockdown on wildly reimagined 19th-century American presidents.

Don’t let the broad shoulders deceive you, though. Combat comes much less naturally to Mr Walker than showbiz. “I was a dancer first,” he says, and his mother, a musician, first got him into singing. (He’s since proven his vocal chops in Spring Awakening, for which Mr Sheik won his Tony Award, and The Threepenny Opera.) By high school, he’d decided that his future lay in acting, broadly defined. He studied at The Juilliard School, the elite New York performing-arts academy.

Mr Walker’s father, a jack of all trades, taught him construction skills that would later come in handy for earning rent money. He also ran a video store at one point. Funny, then, that Mr Walker now finds himself surrounded on a nightly basis by Bateman’s shelves of meticulously organised home videos. “That was my childhood, re-shelving movie boxes,” he says.

It was also, thanks to parental viewing restrictions, full of Hollywood classics. Among his acting icons he lists Messrs Gary Cooper and Gregory Peck, and you can see a little of them – their solidity, their matinee-idol chins – in Mr Walker. That said, his default mode is not deadly serious. He has enormous respect for comedians, and has hosted stand-up evenings in New York for years.

“It’s storytelling at its purest – and it’ll toughen you up real quick,” he explains. He slips into a velvety register to demonstrate his latest riff, a take-off on Bateman’s famous grooming monologue that’s more reflective of his own personal habits. “I use a bar of soap I got at a Holiday Inn in Albuquerque, and an Oral-B electric toothbrush – but I’ve lost the charger, so now it’s just a shitty toothbrush.”

So this Bateman is not into moisturisers and haircare products? “Oh, no, I’m a pig.” Mr Walker snorts. Especially lately, he adds: the protein shakes have been giving him gas.

None of this matters much once the curtain’s up. It’s certainly the last thing on Mr Walker’s mind. The wonder of it all is still with him. “Every night, coming up onto the stage in the tanning bed, I’m like, ‘Am I really doing this?’” Ten years ago, when he was 23 and just out of college, he didn’t imagine himself here. He didn’t not imagine himself here, either.

“I just kind of knew that it’s a long grind, and the ‘overnight success’ actually takes about 10 years – and that actors have less control over their careers than people think. One of the few things we can control is who we work with, and for me, those decisions are less about shaping a career and more about getting better. After every job I’ve learnt something, been better at something or done something that I was afraid of.”

Mr Walker pauses, perhaps worried he’s starting to sound like someone else. “So,” he concludes, “if I can keep doing that, I think my 23-year-old self would give me a douchey high five.”

MR PORTER is providing the wardrobe for the cast of American Psycho – The Musical, now showing on Broadway