If ever there was a reluctant Hollywood star, it’s Joaquin Phoenix. The actor, who has featured in everything from Gladiator to Walk The Line, has never been one for parading himself on red carpets or photocalls. You sense that he’d much rather be burying himself in prep for a character or spending time with actress partner Rooney Mara and their two children, than waving inanely at photographers. But that’s just part of the mystery of this most mercurial of actors. 

Now he’s back as Arthur Fleck for Todd Phillips’ Joker: Folie à Deux, the musical (yes, you read that right) sequel to Joker, the 2019 film that won Phoenix an Oscar and grossed over $1bn, becoming by far the biggest hit of his career. Just don’t expect him to know why. ‘I’m not sure why it resonates with people,’ he shrugged at a press conference during the Venice Film Festival. ‘I think different people are attracted to different elements of the film. That’s what I’m always surprised by when people talk about it.’
 

Perhaps what resonated was the chance to see Phoenix’s utterly unique take on the Joker (traditionally Batman’s villainous nemesis in the DC Comics universe) in a performance that brilliantly re-invented a character already so indelibly played on screen by the likes of Jack Nicholson, Jared Leto and Heath Ledger. A full-bodied transformation, Phoenix tapped into wannabe stand-up comic Fleck’s manic-depressive state; just the sight of him laughing uncontrollably sent shivers down the spine.

This time around, Fleck is incarcerated in Gotham’s Arkham Asylum, awaiting trial for the five murders (six, if you count his mother) he committed in the original movie. It’s in this gloomy pen that he meets Lee Quinzel (Lady Gaga), who fangirls over him. Soon, they’re singing old-time standards such as ‘That’s Entertainment’, and causing mayhem. If Joker was a love letter to revolution and violence, the sequel is a tribute to love itself. Arthur’s ‘quest for love’, says Phoenix, and the ‘safety that I think he yearns for and has yearned for is a big propellent on this one’.

The first sequel of Phoenix’s career, Joker: Folie à Deux isn’t the first romance, however. Past films such as Two Lovers (by his regular collaborator James Gray) show that when he takes on a love story, it feels real and rich; even if he’s falling for his computer’s operating system, as he did in Her. Intensity, however, remains his watchword. Just think of his naval veteran sucked into a Scientology-like cult in The Master, smashing up a toilet in his jail cell. It left no doubt that Phoenix is the modern-day equivalent to Rebel Without A Cause’s James Dean.

Such a desire to perform has always been there, of course. Born in Puerto Rico to missionary parents, his family later settled in Florida where Phoenix and his four siblings were swiftly signed up to a talent agency. A child actor from the age of eight, he first appeared in the 1982 TV version of Seven Brides For Seven Brothers. By the end of that decade, while his brother River was becoming a star, Phoenix was quietly winning roles, including Ron Howard’s Parenthood. But it wasn’t until 1995’s To Die For, starring opposite Nicole Kidman, that the true Phoenix rose.

Observing the now grey-haired 49-year-old, I was reminded of his most notorious Venice appearance, when he featured in I’m Still Here, Casey Affleck’s documentary that chronicled his infamous meltdown of 2008, as he quits acting to forge a career in hip hop. The film showed him ingesting cocaine, ordering sex workers over the internet and treating the iconic TV host David Letterman to a monosyllabic interview, as he slumped in his chair behind shades and bushy beard. People revelled in watching this celebrity implode: until it turned out Phoenix’s madness was all in the aid of an elaborate prank.

It was no surprise that Phoenix’s faked crumbling fooled us all, given what happened in the wake of Walk The Line. After playing the pill-popping Johnny Cash, he checked himself into rehab when his drinking got out of hand. ‘Alcohol was something I relied on too much,’ he said at the time. While many actors and artists have faced addiction issues, it was a worrying moment given his brother River died from a drugs overdose outside LA’s Viper Room club in 1993. 

I’m Still Here showed Phoenix’s twisted humour, enjoying what he called the ‘sense of discomfort’ that this far-reaching Method performance went. Taking things to extremes? It’s always been that way with him. For Lynne Ramsay’s You Were Never Really Here, in which Phoenix played a traumatised military veteran who goes on the hunt for a missing girl, he bulked up considerably. ‘He came eight weeks in advance… I’ve had actors come early to prep but never that early,’ remembers Scottish filmmaker Ramsay. ‘He came to New York, left his home and built up like that in about eight weeks.’

For Joker, he did the opposite, shedding 52lbs to lend would-be stand-up comic Arthur Fleck an almost cadaver-like look that he replicates in Joker: Folie à Deux. ‘This time it felt a bit more complicated,’ he told the assembled Venice press corps, ‘because there was so much dance rehearsal that we were doing, which I didn’t have last time. And it felt a bit more difficult: I’m now 49. I probably shouldn’t do this again! That’s probably it for me.’

While that might be the end to Phoenix’s weight yo-yoing for the sake of a character, he certainly hasn’t lost his appetite for risk. This last 18 months has seen Phoenix push himself to his limits. In the surrealist horror Beau Is Afraid, he was the timid mummy’s boy who goes through a nightmare journey back to the womb, so to speak. A dedication to his fellow cast members spoke volumes. ‘Sometimes you’re just really grateful when you can look into another actor’s eyes and see them looking back; and Joaquin looks back,’ co-star Patti LuPone told me last year. 

Then there was his reunion with Gladiator director Ridley Scott for Napoleon, with Phoenix offering up a masterful turn as the insane French conqueror. Since then, he’s undergone another reunion, with Beau Is Afraid filmmaker Ari Aster for the forthcoming Eddington, in which he plays a smalltown sheriff in New Mexico during the pandemic. Given the extremities of Beau Is Afraid (not least that opening sequence where he’s hounded in his hellish neighbourhood) the mind boggles as to what he and Aster might come up with next. 

Still, for Phoenix, when it doesn’t feel right, it doesn’t feel right. Just before Venice, he quit Todd Haynes’ new gay drama set in the 1930s just five days before production began. The explicit-sounding film was said to contain graphic sex scenes, which would’ve secured it a controversial NC-17 rating in America. Phoenix refused to elaborate on why he quit (‘if I do, I’ll just be sharing my opinion from my perspective,’ he noted in Venice. ‘And the other creators aren’t here to say their piece and it just doesn’t feel like that would be right’). 

While this might tarnish his PR image ever so slightly, it’s clear that Phoenix won’t enter into anything unless he’s 100% committed. Like anyone else, he’s beset by worries, but he uses them. ‘I think the most difficult thing is just stopping the noise in your own head and you just get so caught up in second-guessing yourself and doubts,’ he said in Venice. ‘And you have to have that anxiety and fear because it motivates you.’ There’s no one better at channeling those fears than Joaquin Phoenix. 

Joker: Folie à Deux is in cinemas from Friday 4 October.