An invisible ripple passes through the room as Jared Leto walks in. He's lost inside a bulky duffle jacket and, like many celebrities, is surprisingly diminutive in the flesh, a sort of pocket edition of the tousled heartthrob you know from Requiem For A Dream and My So-Called Life.
But there's no doubting his mega-star wattage. The eyes are bright and questing with just a hint of ice, his face all angles and dramatic swoops, as if hewn from quartz.
"I'm at the point in the night where I am wondering how am I going to find the energy to go on stage," comments the actor-turned rock frontman, to nobody in particular, as he settles into a couch. "Then, the songs COMPEL you go to the place where you need to be. We've been touring since March and we're tired. It's a good tired – a 'battle sleep'."
"We" is Thirty Seconds To Mars, Leto's riotously popular, slightly ridiculous arena band. He put the group together with his brother Shannon just as his movie career was turning stratospheric in the late 90s and, several years ago, did something unthinkable – semi-retired from acting to focus on rock and roll.
It seemed the ultimate folly. When a Hollywood mainstay straps on a guitar, it seldom ends well. Keanu Reeves, Johnny Depp, Russell Crowe ... they've all fuelled the stereotype of the indulgent A-lister cashing in their celebrity chips to inhabit a rock star fantasy. Why would Leto, a gossip mag mainstay briefly engaged to Cameron Diaz in the 2000s, be any different?
As it turned out, Thirty Seconds To Mars were for real. Granted, critics take palpable pleasure in beating up their music, which might be described as Lindsay Lohan's idea of what Radiohead should sound like (is that bad?). However, they've found their fan-base, selling in excess of ten million albums. Such is their success, it has threatened to completely derail Leto's acting: his new movie, the Oscar-tipped Dallas Buyers Club, is his first since 2008.
There's a game you have to play interviewing Leto (41). Backstage at The O2 in Dublin, he's flanked by his brother and by Thirty Seconds To Mars guitarist Tomo Milièeviæ and this is supposed to be a 'group interview', in which we talk about the band's new record and the forthcoming documentary, Artifact, a chronicling of their $30 million legal battle with EMI Music. But, with Dallas Buyers Club sucking up a lot of oxygen and Leto predicted to receive an Oscar nomination, there is an imperative to nudge the conversation towards more open waters.
We start by inquiring how he negotiated the gruelling shoot for Dallas Buyers Club, in which he plays a transgender woman dying from Aids, while simultaneously writing and recording Thirty Seconds To Mars' latest album, Love, Lust, Faith and Dreams (an LP only marginally less preposterous than the title suggests). As has been well documented, the role of the Aids-afflicted Rayon was as all consuming as the virus slowly destroying the character: Leto was required to embark on an extreme diet, shedding so many pounds that by the end he was just ribs and a haunted stare. Not conducive to great songwriting, you would imagine.
"Actually it worked out fine," he says. "I was finishing the album. I think we had begun mixing. It was towards the end of the year. It worked out perfectly in terms of timing for the film. Anyway, we shot the movie very quickly, only 25 days."
In recent red carpet interviews, Leto has appeared to shrug off the suggestion that Rayon may win him an Oscar. Speaking at the Governor's Ball in New York in November he conspicuously played down his chances.
"It's nuts," he said. "They don't give Oscars to people like me."
He is more considered as Day & Night brings the subject up. Sure, he'd like to win an Oscar. Who doesn't want to see their work publicly acknowledged? He would never cold shoulder such an opportunity.
"I wouldn't ever say that I don't care," he says. "I've made a lot of small movies in my life. Whether it is our new Thirty Seconds To Mars documentary Artifact, a film we made ourselves or [Dallas Buyers Club] it is great to have a celebration of art and creativity. That is wonderful. It doesn't always happen that you are invited to the party. I don't snub my nose at it."
With Thirty Seconds To Mars in the middle of a marathon world tour, is the Oscar talk and Dallas Buyers Club buzz a distraction? "No. We shot the movie a year ago. Look, I'm basically the same person regardless of what I do. We do undertake different projects, all the time. In fact, most of the time, I'm shooting and editing and working on content."
Though he won't remember, Leto and Day & Night have some history. The last time we conversed he turned a little tetchy when we wondered about all the angst in his music. Our argument, essentially was, 'dude, you're JARED LETO – you're talented and dashing and have dated Scarlett Johansson and Cameron Diaz. What have you got to be angry about?' A chippy sort, he did not take it well, to put it mildly.
"I was born in Louisiana and climbed out of the muddy banks of the Mississippi," he said, indignantly. "My brother and I lived on food stamps. We came from a very humble, blue-collar background, with a vagabond hippy mother. It's an experience that informs us to this day."
Maybe it's the presence of his band-mates but he's more sanguine second time around. Still, he is keen to reinforce the fact he and Shannon grew up borderline destitute in Bossier City, Louisiana. All that they have achieved in life they have done for themselves. He's a self-made man and proud of it.
"I think it shapes your entire outlook," he says. "We are from humble beginnings. That always colours and influences who you are."
Leto, by his own admission, was bad news as a kid. Intelligent yet easily bored he was frequently in trouble at school (indiscretions included "basic arson and thievery"). In a previous interview he has stated that his ambition was to be "a painter or a drug dealer".
Because he is from down at heel origins, Leto says he feels an affinity with Ireland.
"I love this country because people here come from a place where you really have to earn it. The Irish have a fantastic spirit."
This goes beyond the usual guff. In his 1996 movie Last of the High Kings Leto was required to speak in a middle-class Irish accent and pulled off a decent approximation of a south Dublin Mid-atlantic lilt (a feat he replicated in Oliver Stone's car-crash Alexander, of all movies).
"I do feel an affinity. Maybe it is an American reaction – a genuine love of the Irish. It is almost exotic."
Leto is disdainful of 'dilettante' actors who dabble in rock and roll. From the beginning of Thirty Seconds To Mars he has sought to play down his Hollywood celebrity. Initially the three musicians declined to be photographed. Promoters were contractually prohibited from using Leto's name when advertising shows.
Meeting the press, Leto insists that his bandmate's sit in (even if, as is the case today, they are happy to leave the talking to him).
As an actor it is no surprise that he views Thirty Seconds To Mars' battle with EMI in melodramatic terms – or that he would make a documentary about his vicissitudes. Signed to a five-album deal, in 2008 Leto and company tried to extract themselves from the arrangement, feeling they were not adequately compensated (they say they never saw a cent off the ten million records they sold). In response, EMI hit them with a $30 million lawsuit. The way Leto tells it, all that the group had worked for – indeed their very existence – was jeopardised (a California court eventually ruled in favour of Thirty Seconds To Mars – ironically they re-signed to EMI soon afterwards).
"We were holed up in a house in the Hollywood hills fighting for survival," says Leto. "In hindsight it was an important time for us. Out of that struggle came our album This Is War. It was an extraordinary journey.
"Most of the people I interview in Artifact are employees of record companies. They were treated as badly if not worse than us. I think the movie is an interesting look at the music industry, which was caught by the arm of technology and spun around by the tail.
"We were a band that had success on a scale we never dreamed possible only to find out we were not being treated right. So we decided to fight."
Artifact has just been released on iTunes.