‘What do girls in bikinis have to do with solving crime?’

Growing up, Reese Witherspoon’s dad was a huge James Bond fan – which meant she also watched a lot of 007 films.

But she questioned why the girls all wore bikinis, with the young Reese asking herself what their revealing attire had to do with solving a crime.

The Oscar-winning actress – and now novelist – says that’s why she wanted her new thriller to centre on a woman who has a unique skill, rather than being about her sex appeal.

Witherspoon, 49, is best known for roles in Legally Blonde and The Morning Show, but has now written her first adult fiction book.

Gone Before Goodbye, co-written with bestselling author Harlan Coben, tells the story of a talented surgeon called Maggie, who is trapped in a deadly conspiracy.

Speaking exclusively to BBC News, she admits that part of her was worrying, “Oh God, why did I do this?” – but says she also felt excited to see her idea come to life.

Witherspoon, who already runs an influential book club that’s picked out hits like Where the Crawdads Sing, adds that she mainly cares about how other writers will receive it. “I have so much reverence for authors,” she says.

Witherspoon was born in New Orleans to a medical doctor father and a mother who worked as a nurse.

Her breakthrough role came with the 1999 teen drama Cruel Intentions, alongside her now-ex husband Ryan Phillippe.

Legally Blonde, released in 2001, made her a major star, and was followed by roles including country singer June Carter Cash in Walk The Line, which earned her an Academy Award in 2006.

Witherspoon says her parents’ line of work helped inspire the characters in her new novel.

“I grew up in a medical military family and I grew up on a military base, so I was surrounded by other mums and dads who were medical military people,” she says.

“There was this sense of service, and that what they were doing was an important service to humanity, but also to their country.”

“We both have the viewpoint that doctors are heroic,” adds Coben, who is married to a pediatrician. “They really are. I mean, it’s a cool profession.”

In the book, Maggie has lost her medical licence after a series of tragedies, but is thrown a lifeline by a former colleague.

The theme of career setbacks is familiar to Witherspoon, who starred a string of poorly received films in the years after her Oscar win and her 2008 divorce from Phillippe, with whom she shares two children.

In 2014, she opened up in an interview about how her marriage breakdown affected her career.

“You can’t really be very creative when you feel like your brain is scrambled eggs,” she told CBS’s 60 Minutes. “I was just kind of floundering career-wise. I wasn’t making things I was passionate about.”

Asked whether her personal experience of a career setback inspired her book’s plotline, Witherspoon says: “I think every great story has a character who is taken to their knees. We just happen to start the story with her on her knees.”

It was “a great place to start” the book, she adds, “because it can really only go up from there”.

Witherspoon’s acting career has bounced back. And through her production company Hello Sunshine, she has made a point of celebrating strong female characters through films and TV series including The Morning Show and Big Little Lies, which she produced and starred in.

I ask Witherspoon how rare it is to see a female character like Maggie, who is not about her sex appeal but rather about her particular skill.

“Growing up, I always saw James Bond movies, my dad was obsessed with them, but I was like, why are [the girls] all in bikinis, and I don’t understand what that’s got to do with solving the crime,” she replies.

“If I was going to do a thriller, I wanted the woman to be at the centre of it. I wanted her to have a unique skillset everybody in the world wanted, but she didn’t even realise it, and that she doesn’t have to shoot guns or punch bad guys. She’s actually just very smart and very intuitive and an incredible surgeon.”

But the film industry still has further to go in creating such roles for women, Witherspoon suggests.

When I ask whether Hollywood still suffers from a lack of strong female leads, the A-lister says: “I always see the gap, I see the white space.

“I started Hello Sunshine in 2011 because I just wasn’t seeing complex storytelling for women in the movie space.

“So, in a way, I was just taking the relationships I’ve had from 30 years of being an actor and just helping shine a light on women who were ready for those opportunities.”

Entertainment journalist Lauren Morris believes Witherspoon has been “quite clever” in the way she’s built her business empire.

“She has her book club, where she publicises books, often centring female stories. Then she has her production company, where she adapts it for TV or film, and she often stars in it herself too,” she says.

“It’s a good business model and it’s working well for her.”

Celebrity novels have been all the rage in recent years, with stars such as Keanu Reeves and Millie Bobby Brown among those releasing books.

Often, collaborations involve a ghostwriter or co-author who does the majority of the writing, with minimal input from the celebrity. Reeves admitted as much to BBC News last year, when he said his novel had been mostly written by British science fiction author China Miéville.

But both Witherspoon and Coben insist that wasn’t the case for them. Witherspoon originally brought the idea to Coben, and the pair say they were both involved in the writing, to the point that – according to Witherspoon – “we couldn’t figure out who wrote what”.

A number of Coben’s books have recently been adapted for the small screen, with mystery thriller Fool Me Once becoming one of Netflix’s most-watched dramas last year.

So will Gone Before Goodbye get the same treatment? For Coben, the answer is yes.

“I think one day it’ll be adapted. I think I have somebody in mind who I think would like to play Maggie, but I’m not going to say anything,” he says.

Is he thinking about Witherspoon by any chance? He laughs. “Yeah.”

I ask Witherspoon whether she sees herself in Maggie.

“Every character I play is some part of my personality,” she responds. “My personality is a big pie. Each character is a piece of the pie.”

So, having conquered film, TV, book clubs and now novels, what’s next?

“Wow, when you put it like that, I want to lie down,” Witherspoon laughs.

“I’m just really enjoying this moment. This is a big new frontier for me. And it just made me feel like, gosh, creativity doesn’t stop at any one age. It just goes on and on.”

Gone Before Goodbye is published on 23 October in the UK.