BLINK and you may have missed Amanda Ryan's last appearance on the York Theatre Royal stage.

"I was in Headlong's The Winter's Tale and we were there for only two nights in 2009," she recalls of her whistle-stop visit during the September TakeOver festival. "I played Hermione, which was a part I'd always wanted to play since I was in the youth theatre at the Young Vic. I used to usher as well, paint the stage, anything! I would put in as much effort as I could do into everything."

Such determination has since paid off in a professional career on stage and screen that has included playing Lettice Howard alongside Cate Blanchett in Elizabeth and two years as Carrie Rogers in in Channel 4's late-night scallywag sitcom Shameless.

Now she is in York once more, starring in Juliet Forster's Theatre Royal production of Harold Pinter's 1978 play Betrayal in the role of Emma, who is having an affair with her husband Robert's best friend and fellow publisher, Jerry.

It is a backwards-winding play from 1977 to the affair's start in 1968, built on lies and deceit. "Everyone may know how to be truthful in those situations but... when you bring it to the stage in a Pinter play, these characters have great masks. They could just shout at each other or cry, but we did a lot of experimenting in rehearsals with Juliet giving us the chance to take it to the limits, to see what's under the surface.

"At one point, I was banging my fists on the bed, pulling off the table cloth, as we had to see what was exposed by doing that because we're all lying to each other in this play."

In rehearsals, on her script, Amanda wrote next to each line whether it was the truth or a lie. "In the scene in Venice, Emma is just lying throughout, so there's double thoughts going on all the time: what she's thinking and what she's saying!" she says.

"It's a great play because each of the characters generally comes into a scene with a secret or having information that the other doesn't, but during that scene or by the end of it, the secret or information is revealed, so you come into that scene knowing what you're hiding, which influences how you play it."

Emma is enjoying playing a character at odds with her own way of living her life. "I would like to think that I don't have these masks that these characters have; I think I am more direct in my feelings," she says. "What I've enjoyed doing is trying to find the truth of Emma having an affair with her husband's best friend for seven years, because it's not something I could do."

Betrayal is Amanda's second show in North Yorkshire this year, having appeared at the Stephen Joseph Theatre, Scarborough, in Shelagh Stephenson's dark, sad comedy The Memory Of Water in April. "I was playing mad, needy Catherine, and there was no down-time in that role," she recalls. "It was a real work-out!"

Betrayal runs at York Theatre Royal until Saturday, 7.30pm, plus 2pm, Thursday, and 2.30pm, Saturday. Box office: 01904 623568 or at yorktheatreroyal.co.uk