Although Rachael Stirling confesses that the prospect of playing Medea fills her with 'utter fear and terror', she's still full of an infectious gaiety during a lunchtime break from the demanding rehearsals of this co production between the renowned Headlong Theatre, Watford Palace and Citizen’s Theatre Glasgow. Nor does she seem especially daunted by the fact that she's playing a role in which her mother, the redoubtable Dame Diana Rigg, excelled in a revival of the Euripides classic in the 1990s. Nevertheless she recognises the fact that Medea presents the actress playing her with a particular set of challenges.
'I could tell from the hushed tones of my agent that he was ringing to tell me that I'd been offered something special,' says Rachael. 'It wasn't a run of the mill television or film job. If you get asked to play a part that makes you feel frightened then you have to do it. Medea is the opportunity of a lifetime.'
She has warm praise for what writer/director Mike Bartlett has achieved in re-booting this jewel of classical Greek theatre.
'Often you see updates of Greek drama where you get a sense of the original play being shoe-horned into an inappropriate shape but I think that with this play, it's been a very smooth transition. It's the same woman, the same Medea: Mike hasn't compromised on anything. And for all the complexities of the play, Medea is still fundamentally about a complicated woman who is suffering from a broken heart and who cannot accept that her husband has run off with somebody else.'
The Greek myth, which forms the basis of the traditional narrative, relates how Medea, a princess of Colchis, betrayed her family and her country by helping Jason steal its famed Golden Fleece. Mike Bartlett, by contrast, has imagined that the couple have met on holiday in Crete when Medea has rescued Jason from drowning. They have married and set up home together in a young executives' estate, deep in suburbia.
'Medea is already seen as an outsider in this community and the fact that she's clever, that she's an intelligent woman further sets her apart from her neighbours,' argues Rachael. 'Men hate clever women; it goes against all the rules. At the same time, she can be very witty and this has helped her form some friendships. There's always the sense, however, that you'd prefer to see Medea being entertaining on stage rather than sitting next to you in the auditorium.'
Medea is credited with possessing magic powers, a belief that adds weight to her outsider status. Doesn't that characteristic make it hard to think of her as a contemporary woman?
'That is why it was important for us to make sure that the way she takes her revenge is rooted in reality,' explains Rachael. 'What she does is achievable. Medea then turns on her own son. I have a brother of about his age and I love the bones in his body and I couldn't do anything to hurt him. However, in researching the subject and looking at cases of child abuse in which mothers and fathers harm their children, I've come across the theory that the child comes to embody what the parents feel is their weakness. As a result, they stop empathising with this little person and they become detached from their natural instincts as parents.'
It's important to remember, says Rachael, that Medea can be good company.
'She'll make you laugh with her irreverence and she'll speak her mind, whatever the situation. There isn't an ounce of self-pity in her and there's even something joyful in the agony of what she has to endure. In a way, she's quite naive about people and about her marriage. Medea's attitude to Jason is quite clear. He made a promise to her and then he broke it. Medea doesn't believe in this modern-day relaxation in standards of behaviour.'
Rachael is keeping shtum about how she's preparing to chart all the various aspects of Medea and while she is full of the fierce concentration which this role demands, she's not looking for any special sympathy.
'I always hate it when I hear actors talking about the process of what they do so I'll keep my thoughts to myself,' she says. 'And I'm not complaining about the strain of playing Medea. It's not as if we're saving lives.'
Rachael is extremely excited about a very special episode of Dr. Who which we'll be seeing next spring. Written specifically for Rachael and Dame Diana by Mark Gatiss, it will be the first time that mother and daughter have appeared together.
'It was an amazing experience,' says Rachael. 'Mark's been a good buddy of mine forever and he came up to me one day and he asked if Mum would be interested in doing this lovely script. Normally when we've been asked to act together, it's been either to do Hay Fever or The Importance of Being Earnest so this made a nice change. The script was so joyous, so silly and so camp; we had a marvellous time doing it.'
Although Rachael acted in school plays, with the National Youth Theatre and at university, where she took a degree in Art History, she didn't automatically choose to follow in her mother's footsteps.
'My Mum was quoted in an interview, saying that I wouldn't become an actor, although she'd never asked me about it. I think I always knew I would but I've never been somebody who's made long-term plans in case I don't achieve my goals and then I'll feel as if I'm stagnating. I was a bit of a backstage baby but I wasn't at all precocious and there was never a light bulb moment when I decided to go on the stage. However, acting has always satisfied me, both intellectually and emotionally in a partnership of the head and the heart, and I think that inwardly I always knew that I would do it professionally.'
Rachael's father, the theatre producer Archie Stirling, is less high profile than her mother. What have the Stirling genes contributed to her?
'I think that my Dad is the yang to my Mum's ying,' she says. 'There's a bit of a Bertie Wooster about my father. He's very easy-going, he never judges people and we get on brilliantly. I am aware of the Stirlings, of course, and that the family were once very grand but that's all in the past.'
This tour of Medea marks the first time that Rachael has taken to the road. Indeed, this engagement marks a series of firsts.
'I can't wait to get to Glasgow to play the Citizens' Theatre. Although I appeared at the Theatre Royal in Glasgow with the National Youth Theatre, this will be the first time I've acted professionally in Scotland. I'm also looking forward to going back to Cardiff where we made the episode of Dr.Who; I hope the fans will come to see us.'
For the future, post Medea, Rachael is hoping that this autumn's The Bletchley Circle, which has performed strongly in the ratings, will be re-commissioned by ITV. If not, there are a number of different skills on which Rachael the Renaissance Woman can fall back on. She has featured as a skilled interviewer on Radio Four's Loose Ends, for example.
'I was very well schooled in the art of interviewing by Ned Sherrin, who used to present the programme,' Rachael explains. 'You learn to spot the nervous guests. When you see the beads of sweat forming on their upper lip, you know you're going to have to jolly them along. And I recently spent three months pulling pints in a pub. I'd become so fed up with the poor quality of the scripts I was reading that I told my agent not to send me any more. Instead, on Saturdays, I helped a group of wee bairns with their reading and I loved working with the little 'uns.'
Medea comes to Richmond Theatre from Tuesday 20 to Saturday 24 November. Click here for further information.