Helen Giltrow has her first book published this week

Numerous times I’ve stopped writing, looked up, and been surprised to find I’m in a house in East Oxford on a sunny day, and not, say, standing in a shrubbery in the middle of a rainstorm, watching a house where a murderer may be hiding,” says first-time novelist Helen Giltrow.

“I get very immersed in what I’m writing, and sometimes it’s hard to surface.”

And it’s quite a world to be immersed in.

Violence and torture feature strongly in The Distance, Helen’s edge-of-the-seat thriller which was published yesterday.

There’s also plenty of intrigue and suspense when Charlotte Alton, aka Karla, skilled at buying and selling information, unearthing secrets and fabricating new identities, is induced to help a hired assassin enter an experimental high security prison called The Program – a walled-in abandoned area of London where convicts create their own society.

She steps out of the shadows to take a more hands-on role than she’s done for a long time and discovers there’s far more to the case than first imagined.

The body count rises and so does the graphic violence. Exploring the issues of guilt and moral ambiguity, it’s a world away from chick lit or even the new genre of domestic noir favoured by many women writers.

“Maybe it’s true that women writers don’t tend to write this sort of hard-edged thriller. But many of the female writers I rate do tackle violence – sometimes extreme violence – and do it really well,” says Helen, who read Modern History at Christ Church, Oxford, and has worked extensively in publishing, including ten years as a commissioning editor for Oxford University Press.

“Look at Val McDermid’s The Mermaids Singing, or Lauren Beukes’ The Shining Girls. Or anything by Denise Mina, who’s such an intelligent and humane writer; when she writes about violence it feels true but also – deliberately – very shocking. So I’ve never thought that violence was something women writers didn’t tackle.”

The book, which won three six-figure deals at the 2012 London Book Fair and will be published in the US, Germany and Japan as well as the UK, has been a long time coming for Helen, who is in her late fourties.

“As soon as I learned to write, I started writing stories,” she says.

“I’ve still got the first story I wrote (and illustrated), about a shoal of daredevil fish who come to the rescue of a mermaid. I was five at the time.

“I wrote three full-length novels, a radio play and a TV script in my teens but it was all just for fun, and writing got shelved when school exams, and then university, came along.

“I started writing again straight after my finals. But my dad – whose own father had been unemployed for large parts of his childhood – worried a lot about money, and always stressed the need to get ‘a proper job’. So I worked first as a bookseller and then in publishing. I never thought I could make a living out of writing.”

After working as a bookseller, in Islington in London, Helen took part in a graduate training scheme and got an assistant editor’s job in educational publishing.

From there she moved to the educational division of Oxford University Press, commissioning schoolbooks, where she worked for 11 years.

The job involved working out what resources teachers needed, finding authors and guiding the books through the publishing process.

“All that time I was also writing – usually crime novels – but I kept quiet about it. And increasingly, as my career progressed, I found it hard to make time to write.”

Then, in 2001, she got the idea for the book which would eventually become The Distance.

“I had enough ideas to write the first 3,000 words of the story and a rough synopsis, which I entered for the Crime Writers’ Association’s annual Debut Dagger competition in 2001.”

Inspired and eager, Helen resigned her job (“That’s how excited I was”) and planned to take a year off to write the book, before looking for work again.

“Unfortunately half an hour before my office leaving party I got a call to say that my dad – now in his late 80s – had become confused and aggressive, and had then disappeared. I went through most of the party waiting for news.”

Fortunately police found Helen’s father unhurt but he was admitted to hospital for tests and Alzheimer’s was diagnosed.

“My mum wanted to keep him at home as long as possible, but she needed help. So my plans changed overnight,” says Helen, who was brought up in Cheltenham.

“By the time I learned I’d made the Debut Dagger shortlist, my year off looked completely different.”

She never went back to full-time work. “My parents lived an hour’s drive away and I never knew when the phone would ring and I’d have to drop everything. Eventually I started working as a freelance editor. I tried to fit in writing when I could but it wasn’t always easy.”

Her father’s death in 2003 was followed by a wave of other illnesses and deaths and she found it impossible to write.

“I guess for some people, writing is escapist fun but I was writing a hard-edged crime novel. The genre fascinates me – it’s all I’ve ever wanted to write – but I reached a point where I simply didn’t want read crime novels, let alone write one. I stopped completely,” she says.

That period lasted until early 2009.

“By then Mum had been diagnosed with Alzheimer’s too – but I’d found her somewhere terrific to live (she’s still there now, and I see her every weekend), I’d renovated her house and rented it out to pay for her care, and suddenly I had some time,” says Helen, whose partner (“a great bloke called Geoff”) lives in Witney. “We don’t live together – maybe that’s our secret,” she says of the 20-year relationship.

The book came back to her and between 2001 and 2009 she wrote in “short bursts with long layoffs in between”. Then, in 2010, she took on too much paid work and “got sucked into other projects which really I should have said no to”.

She had a health scare and spent much of December waiting for the all-clear, working “stupid hours” on freelance jobs, and not writing.

“My only day off that month was Christmas Day. I remember sitting down on New Year’s Eve of 2010, and realising I was miserable and it was because I hadn’t touched the book for months. And that was it. I got up on New Year’s Day and started writing. I wrote and rewrote and by early November the book was ready to go out to agents.

“In that whole year I only did the paid work I’d already agreed to do, and largely lived off savings. I wouldn’t recommend this course of action to anyone. But it felt like make or break. And by December 10, I had an agent.”

After another revision, for the agent, the book went out to publishers and five wanted to snap it up.

Helen, who is clearly a perfectionist, picked the one which suggested a list of things which needed more work.

“I had an idea that although I’d written the book to the best of my abilities, there was still a better book to be written – I just didn’t know how to do it. I wanted to find the editor who felt the same. His (Bill Massey at Orion) list was the same as mine.”

So a final rewrite began which included rewriting a third of the book. It was finally finished in May 2013.

“So it’s been a very long and complex process,” says Helen, without any overstatement.

But hopefully her next book won’t be so long in the making.

“I’m writing full-time now, thanks to the publishing deal,” says Helen.

“So I no longer have to chase editing jobs and I can concentrate on the sequel – which is great.”

And it’s great for readers too. After staying up far too late to finish an advance copy of The Distance, I can vouch for its fast-paced, page-turning qualities. I’d hate to wait more than a decade to read more.