Much of Bodily Harm (Macmillan pounds 14.99) is set inside a jail and one of its two narrators, Pat, is a mentally ill offender, sentenced for an unprovoked knife attack on a young woman he had never met before. The novel's picture of life inside Britain's penal institutions is disturbing and wholly believable, exposing a violent, amoral environment where the dictates of punishment leave little time for notions of healing or reform.
Prisons and prisoners have always been a part of Rachel Billington's life. One of her earliest memories is of the parents of Christopher Craig visiting her family home in the 1950s to appeal for her father's help, following their son's conviction for killing a policeman.
Yet until she began work on Bodily Harm, penal reform wasn't a subject that interested her: 'Although I was always aware of that other world, heard it talked about, I think if anything I developed a thick skin. Although I encourage everyone to do it now, I'm ashamed to admit that I was never even curious enough to visit a prison.'
Before condemning herself, she might plead mitigating circumstances. She had others things to keep her busy - marriage to the film and theatre director Kevin Billington, two sons, two daughters, 11 novels, children's books, radio and television plays, newspaper columns. But when she got the idea for her latest book, after reading of a similar case in America, she joined her father on his travels around Britain's jails - he has been a prison visitor since the 1930s and at 86 still goes on a weekly basis. The family crusade has become infectious. Rachel Billington now acts as a consultant to Inside Time, a national newspaper for prisoners set up with her help last year.
One of the most compelling aspects of Bodily Harm - told in rotating first-person narratives by the attacker and his victim - is its insight into the mind of a psychopath, the mental contortions he performs to avoid addressing the horror of his crime.
Rachel Billington skilfully brings out the parallels between the mental agonies of both central characters. Though they both go back to 'normal' life, their madness remains dormant, set to erupt in a second encounter.
'I was helped by meeting and talking to people in prison,' says the author, while refusing to attribute too much to a cocktail of fact and fiction. 'Some of my novels like Theo and Matilda have been historical, covering several generations, and of course I've had to look back at what was happening then. But in general I don't spend ages researching. I always think it's very hard not to let it show through when you write.' She is equally wary of novels with a strong autobiographical flavour. 'That's always struck me as like writing a diary.'
Indeed there are few parallels for the casual observer to draw between the bleak landscapes and maladjusted characters of Bodily Harm and its author - elegant, tanned, articulate, disturbed only by the arrival home from school of her children. Even the sound of a malfunctioning doorbell that rings at regular intervals, untouched by human hand, fails to dispel her calm and serenity.
She finds the writing of novels 'a privilege' - 'you have endless words to play with. And you're alone.' It's not, of course, all plain sailing. 'The beginning of this novel was very easy. I had that in my head after reading about the American case. But the unfolding was very difficult. I didn't know whether the ending was going to be like a good old horror movie, or offer a glimmer of hope.' She opted for the latter.
For someone so poised, who gives the appearance of being able to deal with every situation, there is a surprising self-doubt in Rachel Billington. Once her books are written, 'I can hardly bear to look at them again because all I can see is the errors.' Her works sell well, especially in America, but defy categorisation. Some, such as The Big Dipper and The Painted Devil, are short, sharp and contemporary with an edge of satire. Others - like A Woman's Age - are historical yarns. This strange mix, made all the more baffling by the psycho-thriller elements in Bodily Harm, has meant that Rachel Billington's work has never been fashionable. 'The only prize I ever won was in 1951 for handwriting.'
Yet there are common threads. 'I like to take regular situations and ordinary people, then allow something extraordinary to happen to them. In the past I have dealt with love out of nowhere. In Bodily Harm it is violence out of nowhere.'