'I'm sh**ting myself," Tadhg Murphy tells me.
"That happens when you really want something and you get it. The enormity of it hits you and the total and complete anxiety sets in. And you start thinking 'I hate me. They will hate me'," he laughs.
Murphy is about to take over from Cillian Murphy in Enda Walsh's 2014 hit show Ballyturk.
When the show premièred at the Galway International Theatre Festival, it became the fastest-selling show in the festival's 40-year history.
It is now being brought to the Abbey stage and Murphy is in the thick of rehearsals.
Corkman Cillian is a big act to follow but I'm surprised to hear Murphy talk of stage fright given his abundant and eclectic body of work.
He has starred in both critically acclaimed artistic hits and big-budget box-office flops.
He was nominated for an IFTA for his role in Boy Eats Girl, was the rugged Norseman Arne in Vikings, has worked for the Gate, the Abbey as well as Druid and he shared the screen with Colin Farrell in blockbuster Alexander.
Growing up in Dublin's Blackrock, Murphy realised he wanted to work in a creative capacity when he was just 13.
A childhood game went awry, and he lost his right eye after being hit by an arrow. He has said that the freak accident ended up being a positive experience as it made him decide what he wanted to do with his life.
In his twenties, he was accepted to study acting at Trinity College. His year was filled with exceptional talent, Celtic Woman's Lisa Lambe, Druid stalwart Aaron Monaghan, and, of course, Oscar-nominee Ruth Negga.
While at college, Negga and Murphy fell madly in love and got engaged. Several years after they gradated, they went their separate ways - but they remain good friends.
Speaking before Sunday night's Oscar ceremony, when the Best Actress award went to Emma Stone, Murphy said the outcome was irrelevant.
"She is f**king phenomenal," he tells me. "Even if she doesn't win, she's done a movie that is really important and that's all that matters really. It's so well-deserved."
At college, Murphy's skill was apparent to the drama department, and, according to Professor Brian Singleton, his "generosity of spirit and spirit of enquiry" have been central to his success.
Over the past year, he has been working on big-budget TV dramas, but has been dreaming of working on Ballyturk for two years.
The set-up is typical of much of Walsh's work: people waiting in a hermetic room for something bigger and better to happen.
In this case, the two men pass the time by acting out skits, flinging themselves around the place and dancing to 1980s pop songs. It's a real trip. The dialogue is frenetic and the play itself has been described as "deliciously strange", "giddily disturbing", "tantalisingly open-ended" and totally "pointless" - depending on who you're reading.
Murphy saw the show when it played in Dublin's Olympia and was transfixed.
"I was blown away by the whole production and I thought I have to do that show. I was so moved by it.
"Afterwards, we went for a pint, and Cillian said 'You have to do it' and two years later, here we are".
Murphy will take over Cillian's role in the play while Stephen Rae is being replaced by Olwen Fouéré in a shrewd piece of gender-blind casting.
It's not the first time Murphy and Walsh have worked together. He starred in the 2008 production of The Walworth Farce - which was a tour de force.
It was so good it inspired one of his good pals, Domhnall Gleeson, to stage an all-family version of it with his father and brother at the Olympia in 2015.
"Enda is my favourite writer and being in this play at the Abbey stage is amazing," he gushes.
In the next few months, Murphy will appear with more frequency on our TV screens.
He will feature in Sky Atlantic's new series Guerrilla, written by Oscar-winning screenwriter John Ridley (12 Years a Slave) and produced by Idris Elba.
The show is set 1970s London and focuses on the Black Power movement.
"I play an IRA guy who is helping to arm people," Murphy says.
He will also star in period drama Will, directed by Shekhar Kapur (Elizabeth: The Dark Age).
This drama by Craig Pearce, the long-time writing partner of Baz Luhrmann, focuses on the life of a young William Shakespeare and the young Dubliner will play his arch nemesis Baxter.
"It was colourful, and great fun and totally different to Guerrilla. And I got to act alongside Colm Meaney - which I always wanted."
Murphy, who currently lives in Berlin, is enjoying being back in Dublin for Ballyturk's run.
"I moved to Berlin three years ago. It's incredible. I like the buzz, and everything is cheaper and there are a lot of poor people being creative," he says. "It's a brilliant city."
I ask if he is moonlighting as a cultural ambassador for the city.
"Yes, you can call my Tadgh Merkle or Angela Murphy," he jokes.
Despite this, he still feels the pull to return.
"I miss Ireland," he says. "So I love coming back to see my friends, do a show and get a hit of the craic."
Ballyturk is at Dublin's Abbey Theatre until March 11