It's funny how quickly life can change.

A few years ago, if anyone would have told me I'd soon be writing books for a living, I'd have thought they were stark raving mad. Back then I was the ultimate corporate queen, slogging away to make partnership in my city headhunting firm. I was far too busy working and focusing on my bonus to even think about doing something creative.

But all too often, it's only when we get what we want that we discover it wasn't what we wanted after all. People thought I was crazy to quit my big bucks city job to write. And to be honest, even I wasn't sure if I'd made the right decision. But at the time I was so desperate for a life change, it had almost ceased to be a decision at all. It was just something I had to try.

The germ of the idea for Adored came to me after I first moved out to Los Angeles in 2001. I was fascinated by the way that so much luxury, wealth and fame could go hand in hand with so much personal misery. You imagine the lives of the people living in those vast Beverly Hills mansions to be perfect, a fairytale. But when you start to meet those people socially, you get a glimpse of a world that is actually full of broken marriages, crushed ambitions and dissatisfaction on a scale I'd never seen before.

I created the McMahons to be the epitome of that world. Duke embodies a certain type of Hollywood Alpha male - he's not just a womanizer but a woman-hater. And yet at his core, he is capable of love. It was important to me that his marriage to Minnie was ultimately based on love, albeit of a very warped variety. It's easy to despise women like Minnie, who remain in abusive marriages with unfaithful partners - to assume that money is their only motivation. But I think life is usually more complicated than that. Love can continue to exist in the most unlikely circumstances, and no one outside a marriage can really understand what makes it tick.

Of course, England also plays a central role in the book. Siena looks on England as a place of exile - I based a lot of the early part of the book on my own experiences at an English Catholic boarding school, from which I also longed to escape. But in the end, ironically, she is drawn inexorably towards Max, who I see as a very English hero.

I spent much of my childhood in the Cotswolds, and I love it there. I wanted Max to be rooted in that world, even though his ambition keeps drawing him back to LA. A lot of the Batcombe scenes are based on my own home and family, and I think homesickness grew to be one of the more constant themes in the book: Max's for England, Siena's for LA, Minnie's for the East Coast . We all tend to long for what we can't have.

Writing a book is enormously rewarding and fun, but it's also harder work than I thought it would be. I spent many hours, alone in my study, wrestling with doubts about Adored: would this or that plot strand work, was this or that character convincing? Things only got easier when I sat back and let the characters speak up for themselves. I realise that probably sounds weird! But to me, Siena and Max, Hunter and Tiffany, Duke and Minnie, Caroline, Henry, Randall Stein. They are all real.

My greatest wish for the book is that, on some level, they become real for you - my readers - too.