"It is astonishing what you can do to women's bodies on a page," says author LS Hilton, cutting an imposing figure with her steely blue eyes, thick cream McQueen jumper and tight blonde ponytail.
"You can torture them and flay them - but you can't let a woman actually enjoy her own body."
Nobody asks what James Bond feels about things. Why should a female character be any different? Why can't a woman do what she likes with her body, without having to discuss her emotions?"
The woman Hilton is describing is her new creation: Judith Rashleigh, voracious in her appetites, sexually uninhibited, completely unapologetic - and the subject of Maestra, Hilton's first thriller, which is being hailed as the new Fifty Shades of Grey. Its author has been crowned the new EL James.
Indeed, Hilton's initial draft caused so much excitement in Hollywood last summer that it sparked a seven-figure bidding war, and a script is already in development. Days later, a three-book publishing deal was agreed and it will be sold in 36 countries.
But first, millions of readers will - like me - meet Judith, whose sexual appetite is so exhaustive that Grey's eponymous hero Christian might suggest a night of foot-rubs and Midsomer Murders instead.
Certainly she is no innocent, submissive Anastasia Steele, the heroine of Grey. Instead, Judith is an assertive self-made woman with an Oxbridge degree and a job in a prestigious London auction house who knows what she wants - socially, sexually, financially - and sets out to get it.
If Anastasia nods back to Charlotte Bronte's
, Judith is William Thackeray's Becky Sharp reborn.
Hilton is confident the book will appeal to a sophisticated, well-heeled crowd. Whereas Fifty Shades of Grey - despite selling more than 125 million copies worldwide, translated into 52 languages - was seen as a slightly guilty read, a book you didn't want to necessarily be caught with, Maestra is talked about as being the volume the beau monde will be happy to flaunt.
"Young women who have read Maestra say they find it uplifting. They have described Judith as inspiring and empowering, which I'm delighted about. I hadn't deliberately set out to do that. But novels run away with you in a way history books don't," says Hilton.
This is a nod to her other "author" self - the well-respected historian and biographer Lisa Hilton, whose latest work, Elizabeth, Renaissance Prince couldn't be less, well, racy. For unlike EL James, who was an amateur "fan fiction" writer before penning the Fifty Shades trilogy, Hilton comes with a rather prim academic back catalogue, and admits she is "quite geeky" at heart.
Her background is not terribly far from that of Judith Rashleigh - both hail from the north west of England, read English at Oxford, and studied art in France and Italy, before interning briefly at Christie's.
But unlike twenty-something protagonist Judith, Lisa - "I'll admit to 40" - is a sedate single mother to 10-year-old daughter Ottavia, following a civilised divorce from Italian composer Nicola Moro.
"My natural habitat is in a library with a pen stuck in my hair," she says.
So how on earth did she move from studying 16th-century queens and nation states to 21st-century swinger clubs and champagne-fuelled, ahem, workouts?
"A couple of years ago, an agent suggested I write something erotic, but she didn't like the manuscript, so I put it in a drawer. The summer before last, I re-read it, liked it and amalgamated it with another novel I had put aside.
"But still no one liked it. I'd reached the point of thinking about publishing it as an e-book, when last February a friend passed it to Mark Smith [the highly respected chief executive of Bonnier Publishing Fiction] and about the same time, it went to Hollywood agent Matthew Snyder.
"There was a sort of textbook auction over it; in a week, the manuscript had been bought by Amy Pascal."
Pascal being the producer behind the new Ghostbusters and Spider-Man films; the screenplay will be written by Erin Cressida Wilsons, who wrote Secretary and The Girl on the Train.That such a stellar development was even possible was so far from Hilton's mind she had just applied for a job teaching creative writing at a London university.
"In the morning, I had a depressing letter that said I wouldn't even be getting an interview. That afternoon, I heard the film rights had sold for seven figures. I was so stunned I threw up."
She adds: "I am enormously grateful, surprised and terrified at the turn of events. When nobody wanted it, I did feel annoyed: I didn't think it was bad and I did feel it could be commercial."
So given its "commercial" nature, how did her parents - a teacher and lecturer in the north-west, react? "My family are phlegmatic," she says. "My mother has read it; my father hasn't. But they are used to me writing books, so it is not that exciting for them."
Indeed, celebrations have been kept to a mummy-daughter sailing holiday in Croatia and some nights in, shopping on Net-A-Porter. But, Hilton explains: "There is a sense you don't want to believe in it yet."
She is quite self-contained - and for all the wild chandelier swinging in Maestra, seems cautious and sober in her approach to life.
The daily routine consists of taking Ottavia to school, a trip to the gym, and then a day spent writing at the kitchen table, "wearing sweat pants and occasionally thinking this is rubbish..." She adds: "Lady Antonia Fraser once told me that writer's block is a luxury that women can't afford. It's only pompous men who can afford to agonise."
Hilton seems as fiercely independent as her character, but warns: "Feminism is such a fraught word. We spend so much time defining and thinking about it.
"I'm all for Jane Austen on a bank note, but did it deserve the column inches and hysteria? No. I didn't set out to write a feminist character, but a modern one. And modern fiction is out of step with what is happening in the real world. Is the sex too explicit? Have you seen the pictures being sent between men and women? Fiction is lagging behind reality."
But does she find it difficult to write about in such graphic, gluttonous detail?
"No. I wanted to talk about things adults do in words adults use. To write about sex that people might do. Judith seeks out what is good, and that doesn't always mean men who look like they are from the cover of Men's Health."
She is curious to know what men will take from that; she certainly hopes they will buy the book.
"It is a non-gendered cover deliberately. I wanted to write a book that men would want to read so it has guns, boats, sex; it's a thriller." With lashings of quite horrifying scenes of violence, too. "As a historian, I love a good battle scene. And violence should be disturbing - it shouldn't be easy to read."
But she knows that her gender may count against her. "People are so rude about female writers, yet look at Hilary Mantel - the most exciting prose stylist writing in the English language. I think Nancy Mitford is an underrated genius. And it is women readers who push the boundaries of fiction through curiosity. They are the biggest buyers and consumers, and are happy to transcend genre. Men just like to read the same book over and over again."
• Maestra by LS Hilton is published by Zaffre