Sarah Waters: 'Is there a poltergeist within me?'

Ever since Sarah Waters turned her university thesis into her first novel, describing the passions of an oyster seller turned music-hall transvestite, her 'lesbo historical romps' (a term she coined) have combined excavations of secret, often camp, histories with a heady escape from the curtain twitching morality of Middle England. Yet with her latest book, The Little Stranger, published on 4 June by Virago, Waters returns us from the seedy backstreets of Victorian London ( Tipping the Velvet), via suburban pornographers ( Fingersmith) and ambulance rides into doomed wartime romances ( The Night Watch), right back to a bourgeois heartland.

Set in post-war Warwickshire (because it's right in the middle of England" she says), Waters invites us to suck in the country air, still smouldering from the emotional wreckage of the War, before settling us by the hearth for her haunted house story about the upper middle-class Ayres family.

Their country pile, like the rural gentry of the time, is in a state of irreversible decay; the imperious Mrs Ayres is mourning her loss of social standing, her manish daughter; Caroline, is a bundle of unfulfilled desires; Roderick, her son, a survivor of war who is still haunted by its savagery; and Susan, the long dead daughter whose memories linger like a purgatorial spirit.

Their anxiety in a fast transforming Britain, with its Labour government and upwardly mobile working class, is reflected by a sense of growing menace felt in the mildewed corridors of their home. For Waters, who sits before me, small, neat, with the meditative air of a scholar, this is her study of the class system at a watershed moment. But it is the absence of a lesbian character that her loyal readership will be likely to notice first. Since her debut, Tipping the Velvet, about lesbian lovers in Victorian England, became the 'crossover' sensation of the late 1990s, (with a prime-time TV adaptation to boot), she has created a series of bold lesbian protagonists that have appealed to the mass market. But she knew straight off with The Little Stranger, that there would be no gay voice, an inevitability for which she has jokingly (but repeatedly) apologised. It was written with the simple ambition of telling a story, she says, and an entitlement, one suspects, for a lesbian writer to be able to produce a 'straight' story once in a while. "The other books have a common agenda in teasing out lesbian stories from parts of history that are regarded as quite heterosexual. This one doesn't have that agenda," she says.

Yet, there are traits of 'queer' fiction that remain. The characters are all outsiders, exiled from the new order in some way; Mrs Ayres feels adrift from the post-war aristocracy of the 'nouveau riche'; Rod's harrowing memories of war alienate him from ordinary life; the narrator, Dr Faraday, is outside of, yet in thrall to the Ayres family circle; and Caroline is a woman at sea from her femininity. Waters however, is quick to quash any queer reading of her character. Those seeking a gay subtext should not mistake her sexual unease with repressed homosexuality. "You may think her part of the lesbian biography but I didn't mean her to be," she insists. Yet Caroline's demons appear to be the most intense, and blame for the rupture in the house is often planted at her feet by society.

The fiction picks up, historically, where Waters' Man Booker nominated The Night Watch, left off, but without its strong female narratives or historical revisionism.

Billed as a ghost story of sorts by Waters, it combines the Gothic gloom of Henry James' The Turn of the Screw, with the generic reference points of Agatha Christie's country-house mysteries, with each character being "picked off" one by one, and every survivor falling under suspicion.

The book represents her most atypical work in many ways. Had it followed in the vein of her first three works, the central narrator would most likely have been the housemaid, Betty, an imaginative below-the-stairs minx, the likes of whom Waters has often given central casting. Instead, she plumped for a far duller mind in her narrative choice. She knew two years ago, when she began plotting the story, that the narrator would be male, she says.

Dr Faraday, a stolid bachelor who has climbed the class system to become a provincial GP, but who still jangles with the chains of class resentment borne from an early life in his parents' servant quarters, was cast in the strong tradition of the empirically-minded narrator who refuses to entertain theories of the paranormal and clings to rational argument, even at its most unconvincing. "I was interested in class and I knew there would be a male narrator, very much in the ghost story mode. Dr Faraday was at first, going to be a much more middle class, transparent narrator, but I became interested in his more complicated relationship with the Ayres family, for whom his mother worked. One of the technical challenges was to make the reader see more than he sees," she says.

Born and raised in a Welsh household, Waters' own family reflects the upward mobility of the 1940s, and its generational domino effects. Her grandparents were employed in service, like Dr Faraday's mother; her parents gained a grammar school education; she was the first to reach university.

"Writing about class at the time did make me reflect on my own family history. Lots of families, mine included, were part of this transformation. My grandparents were in service, my parents wouldn't have dreamt of going that...and my grandparents just couldn't have imagined my going to university."

As a tomboy growing up in Neyland, a small town of 4,000 people on the Pembrokshire coast, Waters was obsessed with gothic horror stories, both in their writing (encouraged by her father), and watching them in double bill instalments of BBC2's Hammer House of Horror. She drew on the literary influences of Henry James and Wilkie Collins to create a ghost story which only ever tip-toes around horror, never fully enacting it. Like James, who was not attracted to literature's "screamers" and "slashers", she creates eerie rumblings within everyday reality - "the strange and sinister embroidered on the normal and easy" as James phrased it. The only moment when the balance tips from everyday dissonance and creepy suggestion to outright horror is when a looking-glass begins to move. "Rod stood perfectly still, in that still room, and watched as the shaving glass shuddered again, then rocked, then began to inch its ways across the washing stand towards him." It is one of the most terrifying moments of the book that even Dr Faraday has trouble dismissing with his hyper-rational theories of psychopathology, and it leaves the reader, once again, questioning his judgement, as well as Rod's. It can all, of course, be explained by psychoanalysis, says Waters; the 'little stranger' as the hysteric of the upper classes as they lose their socio-economic footing, or the expression of Freudian tensions: the siblings, both unmarried, are still attached to Mrs Ayres' apron strings, and it is when Rod attempts to pull away that this demonic other is unleashed. As Caroline hypothesises, the force they suspect is supernatural could be "some sort of energy, or collection of energies. Or something inside us..."

Known for her meticulous research, Waters' first three books, set in 19th century England, were spawned after years of research for a PhD at London University. The Night Watch, which began in 1947 and reversed back in time, took four years to write with a painstaking research process, she says. But her excavation for this book appears less anchored in social history and more in her imagination. Of all her work, this one needed the least research. "I read poltergeist stories from the 1940s. There is a lot of action in the house so I also looked at a lot of Georgian homes. My girlfriend (a copywriter who she met seven years ago) and I would get in the car and take off, packing a picnic and taking in two country homes on the way. She's interested in social history and would notice things as well."

It is chronologically told, without the dextrous, structural zig-zagging of The Night Watch, nor the breathtaking plot twist in Fingersmith which turns the story, dizzyingly, on its head. Its structural simplicity could lie in Waters' desire to tell a story unhampered by the expectations of others.

"The kind of attention I was getting after a Booker prize nomination for Fingersmith (in 2002) was astonishing. I didn't allow myself to take it seriously. Now there was a bigger audience waiting for The Night Watch - that was paralysing actually. Because I went through that with my previous book, I felt more relaxed with this."

The story appears a first, light-footed foray into the ghost story genre, a format only half-followed. Its conclusion suggests it is a haunted house tale without a ghost, a country-home murder with no actual victim, and Waters mischievously gives us an open-ending in a genre that demands explanations. While writing it, Waters says she sensed the rising of a preternatural impulse: "I was reading a lot of poltergeist and haunting books and I thought I might start conjuring one up," she says. "I thought about whether there was a poltergeist within me that might come out." This 'poltergeist within' has arguably defined much of Waters' work, and this time leads us to first to the gates of Middle England, then, like a 'trickateur' of the country-house classes, unleashes a demonic little stranger to play parlour games with our minds.