Since first being published nine years ago, Thomson has become something of a cult. He made his debut with Dreams of Leaving, followed by The Five Gates of Hell (Gothic meets David Lynch), Air and Fire (grand passions and thwarted desires in 19th century Mexico) and the best-selling The Insult (a mystery exploring that twilight area between fantasy and reality). This week sees the publication of Soft which is every bit as unsettling as Thomson's other books.
Thomson, 42, is a tall, gaunt figure. With his cropped greying hair and black velvet coat he looks as if he has strayed from one of his own darker novels. Even as a child he wore a coat down to his ankles. A pupil at Christ's Hospital or the Blue Coat school, ("a public school for poor people"), his uniform consisted of a dark blue overcoat with gold buttons, breeches and yellow socks - people used to pester him on train platforms wanting to buy it from him.
The oldest of three brothers, Thomson was born in Eastbourne. In Thomson's fiction the world oozes menace. Early on, life confirmed that there are things to be anxious about. His father was semi-invalid, a writer of poetry and a prolific painter. Thomson's mother died when he was eight. "She went out to play tennis and never came back." He remembers nothing before or about her death. "What it did was to take the whole first eight years of my life and hide them in a cupboard. I haven't opened that door. I can't. I don't know how to."
According to relatives Thomson had been extremely close to his mother. "And that very fact makes the gap more difficult to understand. My aunt said I carried on as if nothing had happened." Having been made aware of life's fragility, Thomson says he "never had that sense, as young people are supposed to, of time stretching gloriously into the distance."
In spite of this, Thomson describes himself as relaxed. The only time he has frightened himself was when writing The Insult. "In the night, my girlfriend would wake up to the strange noise of my heels drumming at the bottom of the bed."
At 17 Thomson won a scholarship to read medieval history at Cambridge. After working in a factory ("sponge cake division") and travelling abroad, he got a job as the "punk" copywriter in an advertising agency. But he left in order to begin Dreams of Leaving. "I suppose much of my life could be summed up by those three words. Eastbourne, university, family - I wanted to get away from them all."
The Five Gates of Hell started as an experiment in autobiography; Air and Fire - the beautifully-written tale of a passionate Frenchwoman and a no-hoper American prospector - was inspired by a drive through Baja, California. "We got to the Gulf coast and came to Santa Rosalia, where everything was brown and the heat extraordinary. Standing like a mirage was a metal church designed by Gustav Eiffel. I wondered, `Why here?' and that was the mystery around which I built the novel."
The Insult has one of the grabbiest opening sentences in modern fiction; `You've been shot.' Marine life was the genesis. Thomson had been listening to a radio programme about a fish that lives 3000 feet down on the sea bed in the pitch black. "Instead of eyes the fish has an electro-sensitive plate in its head through which it sees. I thought, what if there was a person like that?"
The narrator is the recently blinded, unreliable Martin. "I wanted a condition on which I could build the con- ceit of someone who thinks he can see. It's about the gap between what Martin is describing and what's really there."
His novels hinge on what Thomson calls "the plausibility principle". You take a situation and nudge it to the brink at which it teeters but not quite. Thomson became interested in non-conscious information processing and how we act on things we've absorbed unawares. "Soft takes the idea of advertising and pushes it until it becomes a form of pollution, an irresistible flow of images that threaten your control over your own mind."
Thomson isn't biting the hand that once fed him. ("I like the way advertising makes the city look".) But he does have "a mistrust of big business". The plot revolves around the marketing of a new orangeade called Kwench! The firm's trouble-shooter tells his colleagues: `the objective of advertising is to change the behaviour of the consumer so that they purchase more of the product'. Thomson imagines what would happen if you took this literally and brainwashed punters, feeding a desire for the drink directly into their subconscious.
It may not be new territory but the freshness is in the telling. Thomson's best characters are often the grimly comic ones. Barker Dodds is an ex- crim who has lost his taste for violence. Fredegar and Bade are Barker's preferred reading and he's obsessed with the notion that the whole of England was once forest - an interest not everyone shares. "They say all the land used to be covered by trees." "Yeah?" Jim turned. "What they say that for?"
Thomson doesn't see his books as thrillers, more as "meditations on vulnerability and loss." He likes the idea that what he writes is simply the starting point. "A book is like a piece of software which you feed into someone's hard drive. They can make of it whatever they want to."
`Soft' by Rupert Thomson, published by Bloomsbury, pounds 12.99