Is Ruth Rendell as good as Barbara Vine? Arminta Wallace meets them both, in live flesh, so to speak, during a visit to Dublin to promote the eighth Vine novel, The Brimstone Wedding

AS Ruth Rendel she is the creator of Inspector Wexford, one of television's most genial murder investigators

AS Ruth Rendel she is the creator of Inspector Wexford, one of television's most genial murder investigators. As Barbara Vine she is the author of eight darkly plotted books which we earned her not only sales figures approaching the magic million copies, but also that most elusive of accolades for a writer whose books sell by the bucketload, critical acclaim. And she is plainly, even when drinking coffee in the gently luxurious surroundings of the Shelbourne Hotel on a sunny spring morning, one hell of a tough lady.

She lobs answers into the tape recorder with the merciless accuracy of Boris Becker joining a group of toddlers for a game of beach tennis. Certain questions, usually the personal ones, are dismissed in a couple of syllables; others elicit a sort of autopilot response, polite enough, and packed with useful angles - she was once a journalist, after all - but overlaid by a certain dazed tone, the unmistakeable sign that she has just answered this question for the umpteenth time. Family background? Thwack. "My mother was Swedish, my father was English, they were both teachers, I'm an only child." Does she spend a lot of time writing, to produce a book a year?

Kerrumph. "Oh, well, it's my job, isn't it, it's my business." Coast to coast publicity tours in America? "They do ask some damn fool questions." Ouch.

Time to cut the chat and decide what we really want to know about Ruth Rendell. Where it started, perhaps. And why. Why did she begin to write? "You know, one is either a story teller or one is not. And if you're a story teller, and it's possible for you to write, you will start writing stories down." She started in her twenties, produced a number of stories, sent them to various magazines, and received them by return post. "They were, I think, fairly bad. So I'm not really surprised they weren't published.

She then turned her hand to novels. "I wish I could remember why, but I don't." Again her first manuscript was rejected, but this time the publisher, asked if she had written anything else. As it happened, she had a detective story featuring a policeman by the name of Detective Chief Inspector Wexford.

"I'd written it for fun, just because I had a good idea for a plot and to see if I could write a detectives story. So I invented a detective who was really a mixture of other people's. It was typed in single spacing on foolscap and when I didn't like a bit, I cut it out with a pair of scissors and stuck another bit in." A good deal of cutting and sticking later, the first Inspector Wexford book appeared in print. That was in 1964, and it earned her the princely sum of £75. "Not much, even then - but very soon afterwards, an American publisher took it and paid me 15 times that, which was something else. And after that I just went on writing."

Inspector Wexford was, then, the literary equivalent of an unplanned baby she had no intention of making him run and run. "No, and if I had I would have made him 28 instead of 50." As it was, she changed him substantially over the years. "Well, I realised I was going to have to live with the guy, and I didn't want this tough cop who was really a mixture of Maigret and an American detective and one or two other people; so I made him more liberal, more literate, more tolerant, more sensitive. I wanted a nice man. I also wanted to have a man who had a stable marriage and an interesting wife - I didn't want one of these detectives who are always splitting up and having miserable sex lives and all that stuff."

Is she sorry she didn't make him a woman? "Well, not then, you see. There were no women police officers then, not on that level. If I was starting now. . . " There is a short and uncharacteristic pause before she squashes the idea like a troublesome insect. "I wouldn't dream of having another detective. I don't really want to write detective stories; I mean, I'll write an occasional Wexford, but I want to write other books." What about the success of the TV series has that influenced the development of the character, at all? "No. To me, the television is all right, because it has drawn people's attention to me, it has made me famous in a way that I wasn't before. But I've never developed any of my characters in any way to make any sort of visual appeal, and I've never written a line that I thought would go well on television. A scriptwriter would probably cut it out anyway. And what of the actor who plays Wexford, George Baker? What does she think of him? "Well, he's very good, and it does affect me to this, extent, that, I see Wexford in my mind's eye when I'm writing - and I'm not that sort of writer, I don't really see my characters very much - but if I do, I see George.

It's a long way from, the kindly, affable Wexford to the psychotic delusions of a character like, say, Tim Cornish in No Night Is Too Long, who - just because it suits him - abandons his injured lover on an isolated island off the coast of Alaska, to bleed, starve or freeze to death. Which is why, when she came up with the idea for the story which became the book A dark Adapted Eye. Ruth Rendell decided she needed a pseudonym. She took her own middle name, added her great grand mother's maiden name and began a whole new career. And is it my imagination, or does she soften a little when we start to talk of Barbara Vine, and especially of her latest novel, The Brimstone Wedding - which is, after all, what she has come to Dublin to promote?

"I realised that A Dark Adapted Eye was going to be absolutely different from anything I'd done before," she says. "I would not keep my identity a secret - I never did, that - but I wanted my readers to know it was me, yet have an idea they should expect something else." Her readers took the unwieldy phrase "Ruth Rendell writing as Barbara Vine" in their stride, with the first three Barbara Vine books - A Dark Adapted Eye, A Fatal In version and The House Of Stairs - selling 125,000 copies each. The critics took a bit more convincing.

"For years they asked why I did it. Some say they see no difference - which is nonsense, I think. Others see a great difference. But it suits me very well. You see, if you write crime fiction - or whatever you like to call it - you may not be formulaic, and I hope I'm not, but you still keep within certain bounds, and I felt with Barbara Vine I could write pretty much whatever I liked. Except that it's natural to me to write suspenseful fiction because whatever I write, it's going to have suspense in it, and that sort of enigmatic stuff, and a mystery, because it's in my nature to do that."

ENIGMATIC and suspenseful they undoubtedly are, the Barbara Vine thrillers, with their inexorable unravelling of sinister secrets - painful for the characters involved, compelling for the reader. The secret of writing them, obviously, is in the plot; so does she work out those tortuous story lines mathematically in advance? She is not amused by the suggestion. "Never. Oh, no, no, never.

With the Wexford I do, up to a point - no, I don't plan. I start with an idea. For The Brimstone Wedding, I simply started with the idea of an elderly lady in a nursing home and a carer, because I had an aunt who died in a nursing home last year - it wasn't in the least like the book, of course, but that was my idea. And then the notion of a house that was hidden until the deeds were discovered by the children, because that happened to somebody I knew. Once I had that, the characters came along and then I was there.

If The Brimstone Wedding attracts the same kind of reviews as her last Barbara Vine book, No Night Is Too Long, it will take her a little further along the road which leads away from the category "crime fiction". Does Ruth Rendell, speaking as Barbara Vine, think the end of the crime novel is nigh? "I would think that the old fashioned detective story, which is so much a matter of clues and puzzles is certainly, on the way out, if not already gone. Crime novels now are much more novels of character, and novels which look at the world we live in.

"But, no, they won't die." Hers certainly won't, not for the foreseeable future. A new Barbara Vine is not only guaranteed to make the bestseller lists, it's almost certain, to make it to the screen, whether small or big, as well. BBC1 has already shown serialised versions of A Dark Adapted Eye, A Fatal In version and Gallowglass, and television options have been taken on King Solomon's Carpet and Asta's Book. On the Ruth Rendell front, Claude Chabrol has made a film of A Judgment In Stone, to her obvious delight - "I'm very much a movie person, and La Ceremonie, as it's called, is certainly the best adaptation yet of any of my books" - while Pedro Almodovar is beavering away on Live Flesh.

Meanwhile she intends to keep on doing her job; and so she's currently writing another Wexford and will continue with what she calls "the Wexford/non Wexford pattern" for as long as it suits her. After so many books, does she still enjoy writing? "Yes, I do. I wish I wasn't taken away from it so much, distracted by all the other things that one does, all the things to write and do, see to the television and answer letters and respond to things and, indeed, do publicity." A ghost of a smile hovers behind the eloquent mouth. "I do look back somewhat with nostalgia on those lovely days when I knew I could just go and write and nobody would break into it or disturb me.

"Now I really have to shut myself away in my house by the sea, away from phones and faxes and all the rest. I won't say I sent it, but it wasn't what I had in mind when I first began writing. Coffee?" And having despatched the last damn tool question in double quick time, she pours in a manner that can only be described as positively benign.