Al Pacino and Robert De Niro on ageing, de-ageing and The Irishman

He looks incredulous after he's asked whether he'd consider doing a superhero movie (it's just a few days after Scorsese's comments about Marvel). "We've just done one!" he quips, referring perhaps to the miraculous technology that has allowed the two veterans to transform into men 20-60 years younger than themselves.

After spending three-and-a-half hours immersed in the movie, which centres around the relationship between real-life union boss Jimmy Hoffa (Pacino) and mob hitman Frank Sheeran (De Niro), it comes as a shock to see them in real-life looking their real ages.

A lot of the conversation ahead of The Irishman's release has been focused on the visual effects employed to remove the cracks of old age. But the real success story is in the physicality of the performances.

Pacino, embodying the charismatic and vivacious Hoffa with vigour, truly moves like a man half his age. But it didn't come easily. While his co-star praises their "posture coach" Gary, for helping them to maintain a younger gait on set, Pacino brands him "the annoying man".

“He would just tap me on the shoulder and say, ‘you know, you’re 39’,” Pacino said. “And it wasn’t enough because you would forget it by the time that take had ended.”

Remarkably, this is the first time the Scarface star has worked with Scorsese, despite being two giants in Italian-American filmmaking for the best part of 50 years. He and De Niro have appeared in the same film four times over, though they famously didn't share any screen time in The Godfather 2. Nonetheless, they have maintained a strong bond over the course of their careers.

"A lot of the things that happened to us in our lives professionally were very similar, and so we found that we would occasionally reach out to each other and see each other. It was interesting to be going through similar stuff, because it was really a period of real change in our lives when things started happening, and there was camaraderie brought on by that," Pacino said.

Despite this, De Niro leaves his colleague to do most of the heavy lifting in the interview. He does, however, have some thoughts on Sheeran's complex relationship with guilt.

The Irishman spends a large chunk of its hefty runtime exploring remorse and mortality. As Sheeran, De Niro grows old and weary, and in his old age, he is forced to reckon with his violent actions.

In stark contrast to the cocaine-fuelled protagonist Henry Hill in Scorsese's magnum opus, Goodfellas, Sheeran is a reserved figure: a loyal foot soldier who methodically disposes of his victims with two swift gunshots to the head. He takes no pleasure in his actions, and seems to bury his remorse deep down, only for it to be awakened by his daughter, Peggy (Anna Pacquin), the only moral presence in his life.

"Frank was religious, raised religiously, and had this thing, this dilemma with people he loved where he had to choose between one or the other," De Niro said, referring to the dispute between Hoffa and Sheeran's mafia boss Russell Bufalino (Pesci). He was forced to pick sides, which meant taking the life of a friend. "It weighed on him so much that he had to get it out finally, that it was him. He was a guy with that kind of a conscience."

Sheeran's confession (to a crime which likely constitutes a spoiler for the film, which those inclined can read about here) was revealed in investigative journalist Charles Brandt's non-fiction book I Heard You Paint Houses, upon which The Irishman is based.

"He says in the movie, 'I killed some people, I didn’t know them, I didn’t know their family.' But those people that were his friends, people that he loved, like with any human being he was deeply remorseful," De Niro said.

There is something almost serendipitous about his reunion with Pacino here, in the latter stages of their careers, taking on a film that feels like a coda to the gangster masterpieces they've made along the way. Pacino confirms my suspicions: it's a film that could only come with age.

"Marty [Scorsese] said he saw through a different lens," Pacino said. "I don’t see us doing this 20 years ago, I just don’t. I think its something that could only have happened for us now. So it’s odd that we need youthful makeup."

With this new perspective, Scorsese and his cast of legendary actors manage to give us something we couldn't reasonably have expected: a masterpiece that manages to live up to the lofty expectations that their names, one after another on the poster, will instil in everyone before they click play.

The Irishman is out on Netflix on 27th November 2019