Natasha Cooper likes nothing better than a gory gossip with her crime writing contemporaries, she tells Steve Pratt.

AS a storyteller by both profession and inclination, Natasha Cooper says that "it's difficult to keep your mouth shut". But firmly closed she must keep it and not reveal whodunit until the guilty party in a web-based competition is revealed at the beginning of next month. Only Cooper, best known as author of the Trish Maguire novels, along with her agent and the office of Harrogate Old Peculier Crime Writing Festival are privy to the solution.

She wrote the exclusive story, He Taught Me Everything I Know, as part of this year's festival of which she's programming chair. Visitors to the sites - the festival site plus Theakstons and Waterstone's websites - can follow clues and information to solve the crime and work out whodunit.

"It was extremely difficult because the way I write novels, I usually come to them with an idea or an emotion, and then move on to the characters and the plot. With something like this, where people have to guess, it's all plot and it made my brain ache," says Cooper.

Cooper worked as an editor of non-fiction before putting pen to paper herself. "The nearest to crime I got was The Murders In The Black Museum, an illustrated book by Gordon Honeycombe about the classic murder cases associated with items on show in the police's private museum," she says. "I did get a private tour and there's some horrifying stuff in it. Serial killer souvenirs, very nasty things. The public can't go round, it's very much by permission."

Cooper was "always itchy" to be a writer. "I wanted to write fiction from my earliest memories, but I had this terrible problem in that I am dyslexic," she explains. "I am of an age where they hadn't discovered dyslexia and you were just thought to be thick."

Cooper sounds as excited as a fan at the prospect of meeting some of the authors booked for the 2007 Harrogate crime writing festival, writers such as Harlan Coben, Lee Child and Frederick Forsyth. She knows that last writer "from way back - I used to work at Hutchinson, which published Day Of The Jackal, and the whole office was humming with excitement. That's one of the very best political thrillers".

Many of the visiting writers she already knows through the crime-writing community, which seems to operate as a little world of its own. "I am typical of crime writers in that I like to chat," says Cooper. "It's a lovely world and quite a lot of the writers participate in the forums on the web. There is a whole range of websites where readers and writers exchange views."

Cooper's first published works were historical novels, although "I always had bodies in them". Her first foray into crime novels came with the light-hearted Willow King series, and now the Trish Maguire novels.

"She's not a criminal barrister, she's a commercial barrister which means people come to her because of what she knows and who she knows, and that gives her the potential to move into all different worlds. You still need some suspension of disbelief, but being outside criminal law, it's slightly easier," explains Cooper.

Trisha does have things in common with her creator. "In a way it's a blender and you're making soup. There are things from all over the place that go into your characters," she says.

"There's obviously quite a lot of the author in any character, good or bad, because it comes from your imagination. She has lots of things that I have. She's all sorts of things that I would like to be. She's also very angry in ways that I am not."

Cooper is currently writing a Trish Maguire novel a year. When we spoke she was copy editing the next one, A Poisoned Mind, being published in February. She finds it both a frightening and exciting moment.

"You've spent ages writing and editing, and then it disappears in the publisher's hands, and now it's your last chance to make any changes.

"At this stage, you get to read your novel almost as a reader would and it's wonderful. I'm sometimes surprised by what I read. I think, 'gosh, did I write that?'. I still remember the process on this one, but it's funny how your views change.

"You can read something published two or three years ago and think, 'maybe I should have done that differently'. You might pick up something you wrote long ago and think, 'did I really know that?' and, of course, there are heart-stopping moments."

At the moment she has no plans to retire Trish Maguire, although she remains aware some people feel that any series has a natural end. There's been talk of turning the novels into a TV series as has happened with many a British crime writer's work and the inevitable question of who she'd like to play Trish has cropped up. A difficult question to answer, she says, because there are many who could play her brilliantly. Her current favourite is North-East actress Gina McKee.

But Cooper's immediate concern is the Harrogate festival, now established as an important and influential event in the crime writing calendar. Unlike other conventions, the event is structured so visitors can attend everything.

"The wonderful thing is that the decision was taken at the very beginning that there would be a single strand so the audience isn't split. That means the atmosphere becomes very friendly and the weekend becomes a party," she says.