There was a respectful 2011 BBC version of her fourth novel The Night Watch, and of course Andrew Davies’s “absolutely filthy” 2002 adaptation of her first novel, Tipping the Velvet, which made lesbian sex as much a feature of TV period drama as the Austen ball. Waters is no stranger to film adaptations of her work: last year there was the lavishly erotic The Handmaiden, which transported her 2002 novel Fingersmith to 1930s Korea. “But she’s got an interesting face, which is about as far as the film industry gets towards plainness, isn’t it?” Stomping around in woolly tights and Fair Isle cardies, Wilson does her damndest to pull off frumpiness, but who’s she kidding? “Of course she’s gorgeous,” Waters agrees.

Hundreds Hall and its inhabitants, the Ayres family, are haunted by memories of their glory days: Roddie (Will Poulter), a former RAF pilot, physically and mentally scarred by the war his mother (a regal Charlotte Rampling) still mourning her first child Suki, “my one true love”, who died when she was eight and daughter Caroline – “a ‘natural spinster’ and ‘a clever girl’” – trying to paper over the cracks. Hilary Mantel called it “a perverse hymn to decay”. Set in Warwickshire in the aftermath of the second world war, The Little Stranger shows a world caught between the death of the landed gentry and the birth of modern Britain (a nascent NHS and council housing hover on the horizon). I was really into the gothic as a kid, and loved watching horror films.” So the idea that it has now become a horror film is “incredibly pleasing”.

Waters describes the novel as “a sort of supernatural country house whodunit”, and of all her books, it “is the one right from the heart of me … It’s the book that my 10-year-old self was destined to write. “T here’s something in this house that hates us,” Caroline Ayres ( Ruth Wilson) whispers towards the end of the new film adaptation of Sarah Waters’s 2009 novel The Little Stranger.

Sarah waters handmaiden