Picking up her prize – £3,000 and a hand-crafted beer barrel from one of the UK’s last remaining traditional coopers – courtesy of North Yorkshire family brewer and festival title sponsor T&R Theakston, she told the audience: “Steve is the one person I’d like to be able to share this with. I know he’d say, ‘I told you that you could do it’.” Jo, from Birmingham, continues: “He was my soulmate, a very kind, gentle person, and, when we had children, he gave up work to look after them. He was really supportive, while I was the one with the big job.

“He looked after the kids so I could do that and he encouraged me to write as well. He bought me a laptop for my 40th birthday, and put up with all my crazy ideas.

“There was obviously a lot of rejection and every time I had a setback, he’d play the Doris Day song, I Could Write A Book.”

She revealed her husband was misdiagnosed with pneumonia five times before his rare form of lung cancer was picked up. In her book, she turns this on its head when Kat’s husband’s cancer is missed by an AI programme.

“That gives Kat an instant suspicion of working with AI,” she adds, admitting that In The Blink Of An Eye, even leavened with humour, contains a visceral hatred of the disease that currently affects some three million Britons and their families.

In another cruel blow, Jo lost her mother, Barbara, 68, to breast cancer around the same time. It all fed into the book.

“I just wrote from the heart,” she continues. “My agent said the first draft was a bit miserable because I was writing for myself.

“I needed to write another draft for crime readers. The plot and character never changed. I moved the domestic scenes and put more humour in.”

Having completed her book before the pandemic, it was finally published in January 2023 to immediate acclaim. Today, Jo admits: “The AI detective seems like such an obvious idea to me. Having had it in 2016, I kept thinking someone else was going to write it before me.”

Jo Callaghan wrote the first draft of her award-winning crime novel, featuring an AI detective working alongside a grieving veteran cop, in an extraordinary three-month period as “pure therapy” after losing her beloved partner of 28 years to lung cancer. Having met husband Steve at Glasgow University aged 21, his diagnosis with stage-four cancer came as a devastating blow. Health industry strategist Jo cared for Steve for two-and-a-half years before his death aged 59 in January 2019.

In the wake of his funeral, unable to watch TV and suddenly with time on her hands, Jo wrote her sensational sixth book, In The Blink Of An Eye, which became her first to be published.

And on Thursday night, the 54-year-old received the prestigious Theakston Old Peculier Crime Novel of the Year Award, supported by the Daily and Sunday Express, at the 21st Harrogate crime writing festival in the North Yorkshire spa town.

“Steve died in January and I started writing the book in March a few weeks after the funeral, because I literally didn’t know what to do at night. I had all this free time after being used to caring for him,” she explains.

“I couldn’t bear to sit on the settee and watch telly without him – it took me a couple of years to be able to do that – so I wrote to distract myself and get this story out of my head. My son Conor, now 23, was doing his A-Levels and about to go to university, so I brought together those two themes of loss – losing my husband and with my son about to leave home.”

Simon Theakston, chairman of judges for the award for best crime novel, described Jo’s book as “a boundary-pushing take on the police procedural genre, told with heart and humour and with a plot that kept me hooked until the very last page”.

The debut author, whose previous five books remain unpublished, continues: “It was pure therapy. This is the one book I didn’t write to get published. I needed to write it for myself. Both my children were struggling, so I needed to stay strong for them and I had to work.

“That’s why I think this one got published, because it was authentic. With the others I was trying too hard, I was writing with my telephone voice.”

Despite a strong shortlist, including veterans Mark Billingham, Lisa Jewell, Mick Herron and Liz Nugent, plus newcomer William Hussey, In The Blink Of An Eye, introducing DCS Kat Frank and AI detective Lock, proved an outstanding winner – a highly topical yet deeply poignant examination of loss and grief, told with dark humour.

“It’s not really sunk in yet. I didn’t expect to be long-listed, I didn’t expect to be short-listed and I certainly didn’t expect to win,” smiles Jo, who also has a daughter Aurora, 19.

“I’ve been reading Lisa Jewell since her first book, Ralph’s Party, so she’s been a heroine of mine for years.

“She’s a brilliant writer and None Of This Is True is a stunning book. You just don’t know how she does it. And Strange Sally Diamond [by Liz Nugent] just knocked it out of the park. It was an amazing shortlist.” In her own novel, DCS Frank is coping with the loss of her husband, John, to cancer, while trying to manage a return to work and support her teenage son, Cam, as he waits for his A-Level results.

She is called in by her boss and asked to lead a pilot study examining the use of artificial intelligence in two missing persons cold cases. What transpires is a thrilling and timely page-turner.

But underpinning it all was Jo’s own experience of grief at the loss of her husband.

“We met at Glasgow University when I was 21 so we’d been together for 28 years,” she continues.

“In 2016, I tweeted that I wanted to write a crime novel because I wanted to come to the Harrogate Crime Festival. A few months later, Steve, a non-smoker, was diagnosed with stage-four lung cancer.

“They didn’t expect him to live long, but he was a super-responder to chemotherapy so, to everyone’s surprise, he had five separate regimes of chemo and lived for two-and-a-half years. It was a very tough period for everyone, especially our two children.”

Thankfully, no one did. However, Jo, who has always written despite holding down a high-powered career in the health industry, has latterly come across an Isaac Asimov story from the 1950s, The Caves Of Steel, featuring a robot detective.

Despite her hit book, she has no plans to stop working full-time.

And she doesn’t think AI will replace humans entirely in the workplace. She says: “For me, the challenge is – how does a human and machine team work together?

“How do you use AI to add value and where do you need that human judgment? That’s where the challenge lies for most industries.”

Fascinatingly, she reveals that several British police forces are already using AI programmes to crunch data and help reduce man hours.

It is also used to examine offending patterns and the risk of reoffending, which reflects the plot of the Tom Cruise film Minority Report.

However, she admits the use of a holographic detective in her book takes her story into the realms of sci-fi at the moment. “I was looking a few years ahead,” she admits.

AI remains far from perfect as a crime-fighting tool. Despite hopes that artificial intelligence could remove human bias and aid in logical deduction, some early trials in the US suggest that it actually reinforces prejudices when using information gleaned by humans.

“Particularly in America, we’ve seen that AI-based tools, if the police forces that use them are more likely to target black or poor people, will reflect those prejudices,” says Jo.

Equally, Jo is not especially worried about AI applications, such as the controversial ChatGPT, taking over from human writers – pointing to the Theakston Old Peculier Crime Writing Festival as a case in point. “It makes no economic sense why people travel from all over the country to be here,” she smiles.

“They could just watch it on video, but more than 18,000 people want to come together to meet the authors and other like-minded people. And that’s because there will always be a role for human beings to tell stories because it’s what we like to do and it’s what people need to hear. It’s wonderful.”

With the TV rights to her first book sold, she published a sequel, Leave No Trace, earlier this year and is planning two more books featuring the mismatched detective double-act.

“In book one, it’s a pilot project so they’re just looking at cold cases,” she explains.

“By book two, a young man has been found crucified with his ear sliced off on top of Mount Judd – also known as the ‘Nuneaton Nipple’ – which is a well-known spot in the Midlands. So they get to tackle their first live case amid a media storm.”

The third, as-yet-untitled book is due out next spring.

Today Jo admits the success of In The Blink Of An Eye is somewhat bittersweet. Without the devastating loss of her partner, she might never have completed her book.

“I’ve had an amazing year and people ask what the highlight is,” she adds. “But all the best times are also the worst times. So I get to do lovely trips around the country to placeslike Leamington Spa or Ledburyand Harrogate. And I think, ‘If Steve was here…’.

“In my head it’s a parallel universe; where we would have stayed or gone for a drink or a walk. But out of all the worst things can come some of the best.”

In The Blink Of An Eye by Jo Callaghan (Simon & Schuster, £9.99) is out now. Visit expressbookshop.com or call Express Bookshop on020 3176 3832. Free UK P&P on orders over £25