Denny is a habitual offender who has been emotionally deprived all her life. To compensate, she fixates on older women, and who better to exploit this fixation than Shell Dockley?

Denny will do anything for Shell - including the most violent act. She is a heavily tattoed, butch lesbian with a body made strong by her frequent visits to the gym. Denny's scary because she has so little control of her emotions. But one day a new inmate arrives on G Wing who changes her life forever.

Alicya knows that her character had a hard upbringing. "Denny is well hard - but that comes from a life before prison. A life spent since the age of seven in foster homes and institutions. She has endured a lot of abuse and in prison she is dishing it out, rather than taking it."

But there are happy moments in Denny's life. "She is bang in love with Shell, because as far as Denny is concerned, Shell loves her and they always have a laugh together."

So does Alicya think there are prisoners who do their time like Shell and Denny? "When we went to Winchester prison to do the research I did see one prisoner a bit like Denny.

"She was a bit older, but she had been in institutions for most of her life and seeing her was very useful to me in helping me understand what makes someone react in the way Denny does."

But Alicya knows that prison is just another institution and so doesn't necessarily mean you can leave behind the problems you faced before. "I think the support between the inmates in a women's prison is much greater than in a men's prison. The relationships are stronger - but there is so much that is lonely.I think to get on in prison you do have to be a very strong individual."

So would Alicya liked to have played one of the officers in Bad Girls instead of a prisoner?

"No way. I love playing a prisoner - I think there is so much to get your head round. Much more about relationships goes on in a prisoner's head and I've been able to be really naughty as a prisoner - Denny doesn't live by the rules and so I've enjoyed being able to play that side of her character."