Wild Bill: Rachael Stirling on her new crime show and Rob Lowe's pecs

The star of everything from treasure hunting comedy The Detectorists to erotic Victorian drama Tipping The Velvet is down-to-earth and has a habit of dropping “babe!” or “fricking!” into the conversation, often in the same sentence.

Refreshingly, she doesn’t take showbiz too seriously.

Rachael reveals she hasn’t even signed up for the option of a second series of surefire hit crime comedy-drama Wild Bill, in which she co-stars with American heartthrob Rob Lowe.

“I haven’t signed anything babe,” she says, as if it would be her last thought to do so.

“With a tiny person (Jack, two), you can’t say, ‘I’m going to do more’, but I’m not ruling it out.

So when things go again, like Bletchley Circle or Detectorists, it’s quite a surprise.”

Although obviously keen on the show, Rachael reveals she had only watched the first episode the night before.

Her sofa companion was husband of almost three years Guy Garvey, from the band Elbow.

And for the record he enjoyed it too.

“We howled and guffawed our way through it,” she says.

“Rob is brilliant and it’s got all those cop elements that you want in a drama, and then for titillation purposes, a head in the freezer.

“It also has this wonderful denouement at the end under a fricking...” She stops as we realise we’re about to enter spoiler land and she says instead: “But it’s cinematic too, which it should be with Rob, who brings a bit of Hollywood.”

And he has done that. Filmed in the Fens, in and around the Lincolnshire town of Boston, The West Wing star Lowe plays an American policeman with a great clean-up rate who arrives in the town to shake it up.

On arriving, Lowe himself was pleased with the reaction. He said: “One couple said it was the biggest thing to happen in their town since the war.”

Rachael has a more brutal assessment of the show, set in a place with the highest murder rate in Britain, along with the biggest “Leave” vote in the Brexit referendum.

She says: “Actually, what it is – but dressed up – is a document of a cross-section of society that is a kind of broken, disenfranchised part of Britain, but it also takes a funny, quirky, kind of gentle, occasionally pointed look at where we are as a society.”

What will the people of Boston make of it?

“They were proud as punch – I don’t think they will be particularly shocked. I don’t think it’s an unlikeable portrait of Lincolnshire. It has that endless, bleak Nordic sort of landscape, yet a warm, funny set of characters.”

Rachael plays Judge Lady Mary Harborough, a pillar of the community.

“She and Bill have an unlikely meeting of minds. In the beginning it’s just sex. She sees this pretty boy being helicoptered into her county and thinks to take advantage of it would be no bad thing.

“She’s not so much the sidekick as the side sauce! Your sachet of ketchup. In episode two, she takes no prisoners and is quite blatantly using him for sex but then he ends up in her court...”

Rob Lowe, I suggest, must have a portrait in the attic, having appeared to have kept his looks down the years.

“He’s incredibly handsome and was the object of affection for all the girls at boarding school. It was a hot bed of 600 or so girls’ hormones. So it was a surreal thing to land this part and for him to look pretty similar to what he did then. He looks amazing and everything moves!”

This is Rachael’s third TV production since giving birth to Jack.

“He’s quite naughty. He went face-first down a slide yesterday and the lady who was looking after him showed me a photograph of him with a little tooth in his hand. I thought, ‘Oh God! He’s already got a gap between his teeth, and now he looks like he’s gone 10 rounds with Tyson.

“But that’s the nature of a little boy.”

She has taken Jack on to many sets including The Detectorists, Bletchley Circle and even during rehearsals for her West End play Labour Of Love.

At other times he’s happy to find himself with others.

“Funnily enough, my mum calls him ‘the parcel’ because he can be passed on to anyone.”

Rachael is busier than ever.

She’s rehearsing a new production in Chichester of David Hare’s 1980s play Plenty.

“David is so passionate about his work, and has been in rehearsals too. You will want to spend two hours in the theatre with my central character. She’s amazing.”

Back in Boston, Rachael is convinced that Wild Bill says something about where we are now.

“It’s a way of a having a foreigner look in upon us I suppose. Bill and his daughter, whom he has brought with him, do have some insights along the way.”

She reveals that she visited the Old Bailey for research.

“The court I stumbled on was the opening of the case against Fiona Onasanya, the Peterborough MP. She was being cross-examined.

“She had been so staggering in her achievements but it was eye-bleedingly obvious that she’d done this speeding crime. She was trying to pass it off to her brother, but it was the most fascinating human drama that I’ve ever sat in on.”

Rachael was also delighted to study the judge: “I finally found a woman judge, although I had also read every book that every QC had written along the way.

“What we see in those courtrooms summarises what is happening in our society, how we deal with right and wrong, and whether we have any empathy or sympathy with them. It’s what a society is built on.”

She admits it may be a missed vocation but with a mother like Dame Diana Rigg, it’s difficult to deny the genes.

“Mum will come and see Plenty as a preview and she will give me notes, and she very generously and sweetly asks me to do the same thing. We always do that.”

I suggest that it’s a great mother-daughter relationship. “It’s a very trusting relationship, but why would you not invite her in to preview?”

And if you give a note to her? “She’s brilliant! Because sometimes you’re so into something you could be missing a simple thing. You learn all the time. Age and experience go hand in hand, but sometimes for all your experience you can miss the most obvious thing.

“The trust that we have for one another, means that often we will go, ‘Oh, I know what you mean about that, but I don’t agree!’ Sometimes you can’t see it for all the work that has gone into it.”

Does Guy give you a note? “Guy’s job is just to go, ‘You were brilliant, babe!’”

● Wild Bill, ITV, June 12, 9pm
● Plenty is at the Chichester Festival (cft.org.uk) from Friday until June 29