The Silent Fountain is a brilliant contemporary take on the Gothic tradition of the likes of du Maurier and Bronte. How much were these writers and their novels an influence on the book?

I think it’s hard when writing gothic fiction not to draw on some of the favourites. They’re favourites for a reason, and Rebecca and Jane Eyre are two of the most atmospheric, dramatically romantic novels ever written. I actually re-read Rebecca before starting The Silent Fountain. I just wanted to get into that headspace and remind myself how it felt to finish a du Maurier book. I felt exhilarated, inspired and totally transported to Manderley. I loved how Manderley became a character in itself and I immediately knew I wanted to write about a crumbling, dilapidated mansion of my own. The love tangles in Rebecca are also tantalising, as they are in Jane Eyre. I’m captivated by stories of possessive, obsessive love, and setting this against the faded glamour of a castle estate was impossible to resist.

The change in direction came naturally to me. My previous six books have been glitzy celebrity blockbusters, and while I’ve carried the same glamour and escapism into The Silent Fountain, I felt ready to tackle a darker story. I’ve always wanted to try my hand at a ghostly tale. Plenty of popular women’s fiction – Kate Morton, Lucinda Riley – is concerned with family secrets and hidden pasts, so really the ghostly element is only a small extension of this. But the gothic has the added magic for me. I adore those spooky, windswept tales of deepest lust and darkest loss – gothic romance is about more than love affairs; it’s about the romance of old buildings, of complicated families and defiant heroes and heroines.

Embarking on this new style came at a fitting time in my life: I’d just had my daughter and, what with broken nights and the general upheaval of being a new mother, I unsurprisingly didn’t feel like writing about my characters jumping into bed with each other, when all I wanted to do was crawl into my own bed to do nothing but sleep! Everything in The Silent Fountain was so different to the reality of my life as a tired mum – the glamour, the exotic locations, the suspense – that writing it became something of a refuge. I’d love to keep exploring gothic literature. The novel I’m writing at the moment is set in a Cornish castle and features a war-wounded widower who hires a governess to care for his children. I’m looking to push what I’ve started in The Silent Fountain towards even more exciting territory.

The most intriguing, for me, is Isabella, who represents the villain in the book. I had fun writing her dark, complex, sinister character. I wanted her to offer some real menace, but for us to doubt Vivien’s perception of her sufficiently to wonder if there was more going on beneath the surface. Isabella is mute for much of the novel so this presented its own challenges. I had to make her frightening without her saying a word!

I think she’s both. Is there such a thing as a villain without a cause? The fascinating villains in literature are the complex ones – the ones that aren’t all bad, the ones who might have been saved had their circumstances been different, if they hadn’t suffered their own tragedies. Isabella is complicated. Her past is complicated, as is her devotion to her brother and her desires for the future. She is the perfect nemesis for Vivien because she’s a woman of a similar age, beautiful and enticing and all the more savage for those traits. Rivalry between women is fascinating, so psychological, and I had fun playing with its tensions.

I always knew what Isabella would be responsible for. I gave her salvation in the disclosure of her history, which might for some readers alleviate her crime. I don’t know, though: it doesn’t for me.

Vivien doesn’t do herself any favours. She decides almost immediately that Isabella is out to get her, and in a way it becomes a self-fulfilling prophecy. Vivien’s own insecurities – her need for Gio Moretti to love her and her alone – conjure a contest between the women from the off. Both women see the other as all-powerful. Both women are jealous. Vivien accuses Isabella of being needy when in fact she is equally guilty. I don’t think it’s as black and white as Vivien being the victim and Isabella the architect – at least not at first.

Lucy is our touch-point in the novel, the ordinary, unremarkable girl-next-door through whose eyes we uncover the beating, bleeding heart of the Castillo Barbarossa. She couldn’t be more different to glamorous, faded Vivien - and yet the women have more in common than they realise. Both are hiding from secrets they are unable to face. By the time their paths cross, Vivien is almost wanting her burden to be taken from her: she’s been carrying its weight for too long. There is also a suggestion that Lucy reminds Vivien, physically, of Isabella. Vivien knows she must confront her past, and Lucy is her sole salvation.

In fact, the conclusion of my first draft was very different! My editor encouraged me into the ending the novel has now and I think it’s perfectly bittersweet.

For me, Italy is the ultimate stage for romance and drama. Once I had the crumbling Castillo Barbarossa set deep in the Tuscan hills, the characters just came to life. I’ve visited Florence several times and always wanted to set a book there. I loved following Lucy down the Arno and past the Duomo, and catching all the lovely scents of Florence and Fiesole. It presented the ideal escape from London and carried just enough beauty and exoticism against which Vivien’s story could unfold.

I kept thinking of the classic architecture in Florence - the Uffizi, the Duomo - and dropped those grandiose elements into the Barbarossa. I wanted to get across the sheer scale of the castillo and incorporate stately, imposing styles like Corinthian columns and giant facades. At the same time I imagined those cool, humble chapels in the Fiesole hills with their chipped frescoes and bells ringing cleanly in the morning. The mix of high glamour and slow deterioration is at the heart of the Castillo Barbarossa - as it is at the heart of Vivien.

High point is easy: meeting Jackie Collins while we were judging a writing competition together for ITV’s Lorraine. I devoured all of Jackie’s books when I was a teenager and she was a huge inspiration for my early stories, as well as being a thoroughly nice and generous person. Low point might be when eleven publishers rejected my first novel, Hollywood Sinners, before at the last moment Harlequin picked it up – and the rest is history!

I’m deep into my 2018 book now, another gothic romance, and I’m spooking myself a bit in writing it! I hope this is a good sign…