Aisling O’Sullivan used to think that the world of acting wasn’t meant for “people like” her. In other words ‘twas far from Hollywood that a young woman from “a mountain in Kerry” was reared!

At least, that’s how she felt until she was roughly 25, when she took a leap of faith into the very world she feared most. That’s what’s so inspiring about her success story.

Since then, nine years ago, Aisling has appeared in movies such as The Butcher Boy and Michael Collins. Her theatre work in London alone has encompassed numerous prestige roles including those of the Duchess in The Duchess Of Malfi for the RSC, Julie in Miss Julie and Helen in The Cripple Of Inishmann. In Ireland, meanwhile, she has featured prominently in The Cavalcaders, The Famine and The Murphy Initiative.

Now Aisling is about to make her debut at the Gate Theatre, playing one of the three female leads – along with Marie Mullen and Eileen Walsh – in Mark O’Rowe’s latest play Crestfall.

The play, which is directed by Garry Hynes, is described as focusing on “a place between nightmare and waking, a savage quarter so dark, the tiniest glimmer of light is almost extinguished. Almost.” Crestfall is “shocking” in parts, according to the Gate press release. Why?

“It is a shocking play and could offend people if they weren’t alerted in advance,” Aisling explains. “It’s a great play, profound, poetic and beautiful. But it’s also disturbing – though I can’t exactly say why. But it’s also incredibly uplifting at the end.

“It’s about three women who are very honest and who don’t shy away from the underbelly of humanity – whether in terms of their own individual lives, their relationships to each other or to the world they live in. It’s like a mythical western in ways!”

So is there a three gun shoot-out at dawn!

‘You could say there is,” Aisling says. “There definitely is a showdown of sorts. My character is a woman, living in a town, married, with a child and, through the course of the play, she reveals herself more and more. It’s fascinating to work on, at every level.

“The last play I did was The Duchess Of Malfi, an English classical play for the RSC. And playing the Duchess I had to learn how to use language, and to understand rhythms in classical plays. Which was difficult because I’m Irish. I also had to have an English accent and they have a different way of speaking.

“Yet that has been enormously helpful in this production because, although I’m playing an Irish woman, Mark has written a classical drama. He’s a genius and he’s written rhythms underneath his plays and if you follow the rhythms they tell the story. It’s like Shakespeare.”

Aisling O’Sullivan also is clearly exhilarated by working with Garry Hynes again – despite the latter’s reputation as a demanding director.

“It’s not so much that she’s demanding,” Aisling explains. “She cares passionately about the plays she does. And I do, too. I’d argue to the death for a play. But at some point I can back off because I’m not the director, I can say to myself ‘the director knows more about this’. But she’s in a position of enormous responsibility, enormous authority. And she also works with new plays, so she has to trust her instincts, to protect a play.

“To Garry the work is vital. Particularly when, as is the case with Crestfall, she has four weeks to put on a great piece of theatre. In fact, I believe this play will be around for hundreds of years, so that responsibility, for all of us, is huge. But I definitely think all the work will be worth it.”