NEW YORK − In “Cabaret,” Eddie Redmayne plays the ultimate master of ceremonies: a puckish purveyor of loose morals and tight stockings in Jazz Age Berlin.

But when he’s not onstage at the August Wilson Theatre, which has been stunningly transformed into the decadent Kit Kat Club, the Oscar-winning actor says he has adopted "quite a monastic living." He and his co-star, Gayle Rankin, are texting around the clock on WhatsApp, feverishly trading intel on vitamin drips, throat-coat teas and Chinese medicines. Backstage, you’ll often find them sharing bottles of Gatorade and bags of Lay's potato chips (“The oil is very good for your throat!” Redmayne assures us).

“There’s a morbid fascination that we’re enticing all these people to our club to get boozy and be hedonistic, and we’re going to be stone-cold sober,” he jokes on a Monday morning Zoom call. “I had a Negroni last night to celebrate the last show of the week and instantly felt guilty.”

“Guilty and drunk!” Rankin adds with a laugh. “I had an Aperol Spritz and I was like: ‘Woo! This is crazy!’”

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Their discipline is all part of keeping up with the rigorous demands of “Cabaret,” a bold and bewitching revival of the classic John Kander and Fred Ebb musical, which opens on Broadway April 21. The story is set in pre-Nazi Germany, where an American writer named Cliff (Ato Blankson-Wood) becomes besotted with a devil-may-care showgirl named Sally Bowles (Rankin), who performs at a seedy nightclub overseen by an eccentric Emcee (Redmayne).

Reimagined by director Rebecca Frecknall and performed in the round, the hypnotic new production gives Broadway audiences an experience unlike any other. Theatergoers can arrive an hour early to the club, where they’re whisked through a neon-lit back alley and greeted with free shots of peach schnapps. Inside is a sort of debaucherous Disneyland: allowing guests to roam upstairs to various themed bars, where scantily clad dancers beckon you through beaded curtains and glitter-painted musicians straddle their instruments. Emblems of eyes follow you everywhere, from the club’s ornate wallpaper to a giant, golden disco ball at the entrance.

The idea is to make the audience “discombobulated,” Redmayne says. “You’re being performed to by an extraordinary prologue cast. All of this is to will you to leave your troubles behind, so by the time (the actual show starts), we can seduce and compel you into a space where the story is the thing.”

Throughout the show, Redmayne leers at the crowd from the edge of the stage and slinks around tables of dining guests. During the sultry opening number, “Willkommen,” Rankin’s Sally shakes hands and stumbles over audience members as she wanders through the mezzanine.

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“I weirdly have seen a lot of people I know,” Rankin says. “It’s so intimate and very visceral. And it’s so interesting to have people call you Sally Bowles, like, ‘Hi, Sally!’ I’m like, ‘Oh, yeah! Hey!’”

Gayle Rankin finds 'hope' in the irrepressible singer Sally Bowles

In “Cabaret,” Redmayne and Rankin take on the respective Oscar-winning roles made famous by Joel Grey and Liza Minnelli in Bob Fosse’s 1972 film. Both actors have long histories with the show: Rankin, 34, played prostitute Fraulein Kost in a 2014 Broadway revival before her breakout role in Netflix series “Glow.” Redmayne, 42, won an Olivier Award for his performance as the Emcee in London two years ago – a role he once portrayed in a high-school production in his native England. Even at a young age, he was drawn to the “inscrutability” of the character.

“It was so alive in its abstraction that it was completely freeing, even at 15 years old,” Redmayne recalls. He wasn’t raised in a theatrical family, and his parents had fears about him pursuing a career in the arts. “But when they saw the joy this part gave to me, they got fully behind my passion for it. My mum has some footage of it somewhere that I hope the world will never see.”

Rankin thrillingly delivers the musical’s most iconic numbers, including the heart-wrenching showstopper “Maybe This Time.” For her, it’s the most daunting moment of the night as Sally mulls the possibility of a more domesticated life with Cliff: “It’s about risk,” Rankin says. “Sally’s walking that line of, ‘How much of yourself are you willing to share and expose?’”

Then there’s the haunting title song. The Scottish actress compares Sally to a “phoenix” in that moment, as she wrestles not only with an unwanted pregnancy, but the rise of fascism in her own backyard.

“It’s like a séance that Sally is trying to conjure for herself and the world. She’s trying to stay alive at the end of the show,” Rankin says. “There’s a burning glimmer of hope inside this play, as dark and horrendous and cautionary as this piece of work is. I think Sally knows that.”

Eddie Redmayne's kids partially inspired his performance as the Emcee

The Emcee, meanwhile, shape-shifts from a sad clown to a ghoulish stormtrooper to an Aryan conductor over the course of the evening. Redmayne researched extensively for his performance, taking cues from expressionist German dancer Mary Wigman and the "weird, contorted" drawings of Austrian painter Egon Schiele.

For the Emcee's more playful side, he also found unlikely inspiration in his children, Iris (7) and Luke (6), whom he shares with wife Hannah Bagshawe.

“My kids love coming into the dressing room and trying on the gloves for ‘Money,’” Redmayne says. “My son finds it quite thrilling and does quite a good rendition of ‘Willkommen.’ And my daughter has taken to running around singing the lyrics to ‘Don’t Tell Mama,’ which are wildly inappropriate. ‘You can tell my papa that’s all right / ‘cause he comes in here every night.’

“She’s only 7 and has no idea what she’s singing about,” Redmayne adds with a shrug. “So I’m having to discourage that!”