NEVER mix business with pleasure, and never work with your loved ones.

Martha really should have kept those ideas at the forefront of her mind before agreeing to take on the case of her ex-boyfriend Sean in Silk.

Instead she’s up to her neck in problems, most of them caused by the fact that she can’t consider the facts coolly and dispassionately because of their shared history. His reappearance has shaken the legal eagle in other ways too.

“Martha has to start to reassess what is really important in her life,” says Maxine Peake, who plays her. “This person’s arrival forces Martha to remember the person she was and why she embarked on the career she did. She realises that things have changed greatly and that her teenage goals and ideals have gone somewhat out of the window.”

It’s clear to regular viewers that Martha has convinced herself that Sean wouldn’t lie to her, and so is blind to the massive holes in his story – holes so big, Clive could repeatedly drive a lorry through them without touching the sides.

He tells her something along similar lines, but instead of making her see sense, his words merely make her dig her heels in and become more determined than ever to clear Sean’s name.

“Clive hates her ex-boyfriend and they end up having a massive fight,” says Rupert Penry-Jones, Peake’s co-star. “It took a while to shoot but even longer to get over the bruises. We were a bit bashed up.

We were throwing each other around and against walls, but how much of it will end up in the final cut I don’t know.”

To make matters worse, Martha’s behaviour makes her colleagues wonder if she has what it takes to lead the firm into the future and she herself is forced to question her long-term career as a barrister after the verdict is read out.

But what impact will the trial have on Martha and Clive’s relationship? After all, it’s clear there’s a real spark between them, and they have succumbed to passion in the past. Could they have a future together after all that’s happened?

Penry-Jones isn’t convinced they do: “I don’t know why he decides to suddenly tell her how he feels, but I don’t think you can always explain these things.

“He’s looking at her; she’s dancing, she’s free, so he thinks he’ll give it a go. I think there’s always hope for them. I think she’s who he wants, in the end, but I’m not sure he’ll ever get her.”