Joaquin Phoenix talks the Joker, his career and 'You Were Never Really Here'

Actor Joaquin Phoenix poses at a photo call for the film 'Don't Worry, He Won't Get Far On Foot', during the 68th edition of the International Film Festival Berlin, Berlinale, in Berlin, Germany, Tuesday, Feb. 20, 2018. THE CANADIAN PRESS/AP-Markus Schreiber

TORONTO -- Joaquin Phoenix is coy when asked about rumours he's playing the Joker in an upcoming Batman villain-origin movie.

"The Joker? Who's that? Oh, the Batman Joker," the Oscar-nominated actor says with a raspy chuckle over the line from New York.

It's a glimpse of the playful side of someone who's been labelled enigmatic, private and reclusive.

"I have no idea," he adds. "Here's my thing: I never know what I'm doing until I'm actually doing it, until I'm actually shooting. So there are several things that I think are interesting and I don't know what I'm going to do."

Even his latest film, "You Were Never Really Here," came together rather unexpectedly.

In theatres Friday, the psychological thriller stars Phoenix as a troubled former U.S. soldier who now takes care of his ailing mother -- while working as a mercenary rescuing young women kidnapped for sex-trafficking rings in New York City.

The story, based on a novella by American writer Jonathan Ames, earned Phoenix a best actor award at last year's Cannes Film Festival. Lynne Ramsay, the film's writer-director, also earned a best-screenplay honour.

Phoenix said he was originally supposed to be shooting another project, the upcoming comic western "The Sisters Brothers," when Ramsay contacted him for "You Were Never Really Here." The former is based on the award-winning novel by Vancouver Island native Patrick deWitt.

But then "The Sisters Brothers" was put on hold and the actor suddenly had some time to fill.

"I called (Ramsay) and I said, 'Hey, do you think you could shoot ('You Were Never Really Here') in eight weeks?"' Phoenix says laughing, figuring it was "impossible."

"She said, 'Oh yeah ... we can shoot in two months."'

About his interest in the role, Phoenix said he liked that "You Were Never Really Here" avoided "some of the cliches of the genre."

His character suffers from post-traumatic stress disorder and is considered "brutal" as a mercenary. Yet he's also gentle, courageous and inherently good.

"I thought there was something really touching about that, and not in the kind of cliched way of, 'They kidnapped my daughter. I will not stop until I bury them all,"' says Phoenix, an Oscar nominee for roles in "Gladiator," "Walk the Line" and "The Master."

"It was a character where there was the opportunity to have him question what he was doing throughout the film. At times you feel like, 'Oh, he's going to give up,' or, 'He's just going to completely lose it. He can't finish this."'

Phoenix bulked up in the gym for the role, and researched the psychological effects of trauma.

"Lynne sent me these audio files of fireworks and she said, 'That's what's in his head,"' Phoenix recalls. "I put those headphones on and that is a really big clue."

He also worked with Ty Ritter, founder of Project Child Save, who has rescued kidnapped children sold into sexual slavery.

"When I read the script, I thought it was fiction. I didn't think there were people that really did these extractions, and yet he really does," Phoenix says.

"I just didn't understand how prevalent it was. He told me some statistics that are almost unbelievable."

On the horizon, Phoenix's projects include "The Sisters Brothers" -- which did eventually come together.

He says he got to meet deWitt when the Canadian author and his family visited the set near the end of production.

Despite having retreated from the spotlight a couple of times, and harbouring uncertainty about his future roles, Phoenix does seem committed to acting long-term.

"This is what I do, what I feel in my bones," says Phoenix, whose 2010 mockumentary "I'm Still Here" was about his supposed retirement from acting.

"This was the whole joke of 'I'm Still Here' -- there not a point where you are forced to retire. It's not basketball. It's not like you're like, 'I'm getting in my 30s, it's over.' You can go forever, and it's something that feels good.

"So as long as they'll have me, I guess I'll do it."