Fashion doesn’t just dictate the length of a skirt or style of shoe —it influences almost everything, including novels. No one is more aware of this than novelist Jacquie Walton, from Lower Heyford, whose writing has remained commercial ever since she wrote her first romantic novel at the age of 20, under the pseudonym Maxine Barry.

She followed her romantic period with a series of ten novels centred on Oxfordshire detective Hilary Greene, writing as Faith Martin.

Now, 29 books later, she is once more keeping pace with the times, moving from police procedural-based novels to classic murder mystery stories with a twist at the end, as both she and her publisher believe they are coming back into fashion.

However despite the number of novels she has published, Jacquie feels rather nervous about Birthdays Can Be Murder, written under the pseudonym Joyce Cato. She knows that if her readers don’t like the rather larger-than-life central character — the amateur sleuth Jenny Starling, who is a travelling cook — the novel sinks right away.

She is also concerned that if they guess whodunnit before they get to the end of the book, it will be spoiled for them.

Jacquie has built up a regular local readership during the past five years with her fictional Det Insp Greene, who lives on a narrowboat in Thrupp and works from Thames Valley headquarters in nearby Kidlington.

Speaking about her police heroine, she said: “Not surprisingly, people who live locally enjoy books that are set in Oxford, Bicester, Kidlington, and lots of Oxfordshire villages that they are familiar with. However, there are only so many situations a female detective can face before the reader loses interest. I felt I’d put Hillary Greene through so much that the time had come for me to change hats once again and come up with something different.”

Her publisher agreed the time was right to go for a murder mystery, having unearthed one she had submitted in the 1990s — when murder mysteries were not fashionable — which centred on the activities of a travelling cook.

Apparently a move from one genre to another requires a name change, as Jacquie doesn’t want her regular readers to see a familiar name on the cover of Birthdays can Be Murder, and be disappointed when they discover it is not another Hilary Greene novel. A new style needs a new name, which is why she is now calling herself Joyce Cato.

We meet her new heroine, Jenny Starling, as she drives her ancient red van into the Devon village of Rousham Green, where she has been employed to cook for a dual birthday party at The Beeches, a large Georgian house set in its own lavish garden.

She is not made welcome by the resident cook, who is used to running the kitchen on her own. It is also some time before her help is acknowledged by the police, who have been called to investigate when the birthday twins drink poisoned champagne as the assembled guests toast their health.

However, this tenacious cook, with her razor-sharp mind and Miss Marple approach to untimely deaths, wins out in the end. The police finally accept her expertise and even end up thanking her for her intuitive insights.

Jacquie says that when working out a murder mystery she begins by working out who kills who and why, she then adds other characters who have reason to kill the victim, then writes in further clever twists as the novel comes to its conclusion.

“Classic murder mysteries are hard to write because the plot calls for more structure than necessary in the police procedural novels, which are character driven,” she said, adding that the writer has to be strictly fair with the clues so as not to cheat the reader.

Unfortunately, I felt Jacquie lacked first-hand experience of the way professional cooks work under stress, attributing her heroine with remarkable skills that enable her to create a gourmet dinner for 20, a buffet for 200, and two ornate birthday cakes almost single-handed in just a few hours.

She says that in the second novel in this series Jenny will be in a far smaller house where she will be cooking a traditional Christmas lunch.

l Birthdays Can Be Murder is published by Robert Hale at £18.99.