PREVIEW - Treasure Island at the National Theatre

IT'S a dark and stormy night. Jim, an inn-keeper’s granddaughter, opens the door to a terrifying stranger. At the old sailor’s feet sits a huge sea-chest, full of secrets. Jim invites him in – and her dangerous voyage begins.

Such is the beginning of Robert Louis Stevenson’s classic tale Treasure Island, a story of murder, money and mutiny.

A thrilling new adaptation of the story by Bryony Lavery is being brought to life on the Olivier stage at the National Theatre as part of its winter season.

Among its star-studded cast is Peckham actress Gillian Hanna who plays Jim's granddaughter. It is a role she tells me she's enjoying playing, not least because she gets to keep her feet firmly on the stage.

"It's a hugely exciting production and swash will be buckled all over the place," she chuckles. "There is adventure, swords, fighting, the climbing of rigging and unfurling of the sails - which thankfully I don't have to do but it's all very exciting and terribly dramatic!

"I have found a rocking chair on the stage so I get to oversee things a bit."

For fans of the book Gillian says the production is "pretty faithful" to it and promises it will be "quite scary".

"There are some real jolly 'yo ho ho' types of course but there are some really horrible guys that will kill anyone in their way to get their hands on the money so it's quite scary," she says.

"It's pretty faithful to the bones of the book though there are a few tweaks."

John Silver for example will not be played as an old man but rather someone much younger and rather than Jim living at the inn with her mother, this version sees her live with her grandmother.

"Bryony wanted to make her a lot older," says Gillian. "She's a lovely character. They have this inn on the edge of nowhere but it's hard to make a living and they have a hard life. They don't eat a lot of the time because they are so poor.

"She's very protective of her family but she's a very tough granny and she's a great part to play."

Gillian was able to have input into her characterisation and put her foot down about one aspect of the make up.

"When we were discussing the character they wanted me to have warts," she says. "But because she's the equivalent of a good fairy and she's the grandma who people rely on, I said no. Warts in this sort of show when you are dealing with archetypes have to be on bad characters."

Warts aside it's clear Gillian is enjoying being part of the production which she describes as "huge".

"It was the whole package that appealed," she says warmly. "It's such a classic story - an iconic piece of English literature. It is incredibly well written and rattles along. There are a lot of people who say it's the best book he ever wrote.

"I suppose it's sewn itself into the fabric of our cultural life. The language in it isn't convoluted - it's relatively straightforward and is a real adventure story.

"It's also lovely to work at the National as you are treated so well," she adds. "And it's lovely to work on something that's so big. It suits the Olivier because it's such a huge stage. It's great fun and is a very special show."

That Gillian became an actress in the first place was rather by accident than design though she admits it suits her as she "can't sit still".

"I could never do an office job for eight hours a day," she laughs. "My mum made me take a secretarial course for something to fall back on but I lasted two months - I just couldn't do it.

"By pure fluke I went to university in Dublin to do modern languages. A friend of mine wanted to audition for something at the drama club but was a bit shy so I went along with her and, oh dear, I got the part instead!"

Despite this early success Gillian says she still didn't consider acting as a career. So she continued with her studies, gaining a first class honours degree.

"I did do a few more plays while I was there and then someone asked if I was going to do this properly and a director said he knew someone who ran a theatre in Liverpool. It was the Everyman but I was so idiotic I didn't realise!" she laughs.

"The Everyman called me and in the end that was that."

She then moved to London, eventually settling on Peckham, a place she says she loves and has since enjoyed a successful career both on stage, as a translator, writer and playwright.

"I've lived here for 30 years and have the whole world on my doorstep," she says. "It's fabulous, and I love being near Peckham Rye which is where the oak tree William Blake had his vision of an angel. I'd like to think it's true but I've not seen on yet!

"I love the variety of this job," she adds. "TV, theatre, film, writing, they all present different challenges and different ways of working - besides it's a bit too late to retrain as a brain surgeon!"

Treasure Island is on at the National Theatre until Wednesday, April 8. Tickets from £15. Visit www.nationaltheatre.org or call the box office on 020 7452 3000.