Look at Julia Watson and you inevitably still think of her most famous role to date, ambitious, independent doctor Baz in Casualty.

But in her latest stage role, as Hester Collyer in Rattigan's The Deep Blue Sea, we first meet her on the verge of taking her own life.

"It's a play about a woman who's caught in between two relationships," explains Julia. "It's an amazing play a thriller, a black comedy and a melodrama all at once. It's a real page-turner!"

While Baz wasn't known for her straightforward love-life, for a woman living in Hester's time life was all the more difficult.

"When we meet Hester she has left her husband for a younger man but this is the 50s. She's fighting against the accepted way of life of being looked after and relying on a husband," Julia says.

"Attitudes to divorce and being gay and things were different then, but the emotions are still the same today. The pain felt by all the parties is the same."

But Hester doesn't remain a victim. "The play's about her becoming stronger. She's being castigated for simply falling in love, and she knows he doesn't love her in the same way. But the ending is quite positive it's not about a woman in a passive role."

What's interesting about this play is that Rattigan originally wrote the play about a gay love triangle but the censors wouldn't let it through, so he re-wrote it. Julia feels the message is the same. "It's essentially about people on the outside of respected society," she explains. "Although it's not overtly stated in the play, there's a doctor in it who has obviously lost his job simply because he's gay, for example."

But while she's dismissive of post-war morals, Julia loves the other aspects of being transported back into the 50s. "It's very Brief Encounter. The language is quite clipped and BBC and it's difficult to sound convincing without being too prim and proper!"

She welcomes the historical roles, though, having become ingrained in the public consciousness in largely contemporary roles in Casualty, A Touch of Spice and the children's show Welcome to Orty-Fou, but her stage roles tend to fit that criteria she was last seen in the Bill Kenwright tour of An Ideal Husband.

"I've done so much modern-day TV it's great to be doing period stuff. I love all those big frocks," she smiles. "And I love doing Shakespeare."

Julia's also embarking on a new side her career with a production role, but has still to achieve her ambition of being in a feature film. " I've never seen myself on the big screen," she says ruefully. "Having said that, though, it's probably just as well it might be quite distressing!"

The Deep Blue Sea is at the Palace Theatre, Clarendon Road, Watford from next Friday (February 1) to Saturday February 23.

Performances are at 7.45pm Monday to Thursday and 8pm Friday and Saturday, with Wednesday and Saturday matinees at 2.30pm and 3pm.

Call the theatre box office on 01923 225671 to book tickets, which are priced £4.50-£18.