Stephens is a US author who has spent the past decade writing and producing TV programmes for mainly US audiences, including "Gossip Girl" and "The OC", a long way from the dwarves and underground caverns of his debut novel, The Emerald Atlas (Doubleday).
In the book, siblings Kate, Michael and Emma have spent 10 years being shunted from one terrible orphanage to another after their parents' disappearance. Arriving at their latest orphanage, Cambridge Falls, the children uncover an ancient magical prophecy that is bound up in three books of magic, of which The Emerald Atlas is the first. Only by recovering the atlas from the hands of the dwarves can they prevent the terrible destiny that awaits Cambridge Falls, and safeguard the book from getting into the wrong hands.
A strange world
Stephens took a year off from scripting to write the books after becoming disillusioned with his chosen career. "I had been writing scripts for 10 years and wanted to do something that was my own. You don't need to go far in LA to find an embittered 45-year-old TV writer and I didn't want to be that person.
"Writing for television is such a strange world, you have to write up to 25 episodes of a programme each year and you need to create a lot of drama. You end up thinking: 'Have we done this before and if we have, will anyone notice?'
"What script writing teaches you is to write good dialogue that is character-specific and that pushes the plot forward, and you learn about beginnings and endings - how to structure your scenes and storyline. On the other hand, you also learn to create drama that isn't there; every seven and a half minutes you get a TV ad, so you have to write to that.
"When I was writing as a graduate, I wrote science fiction with fantasy elements, but I turned to children's writing because I was frustrated by contemporary adult fiction -the irony and myopic point of view, which wasn't what I fell in love with in reading as a kid. What I wanted was something that takes you out of yourself.
"The way I learned to write for television was by deconstructing a television show, and I wrote a children's book by deconstructing in the same way. I read books by J K Rowling and Philip Pullman obsessively; I read the first Harry Potter four times and The Goblet of Fire five times. I wanted to write my own children's books and so I took lessons from both these authors. If you're a children's writer, you can't run away from those books because the shadows cast by them are so long, but of course I was anxious about stepping into that territory.
"Creating a book is like building something brick by brick. The writing part is the easiest for me but the plotting is like doing the math of the book and it took me three years start to finish. Each novel in the trilogy will be about the children finding a specific book of magic. I made the first book emerald because we all know that green is the most magical colour. I am not sure what colour the other two books will be.
"The story centres on three siblings and I suppose that was easy for me to write as I am the middle brother with two sisters and there is a degree of accuracy in their squabbling.
"Dwarves also feature largely in the novel because, when I read Tolkien's world where the elves are wonderful and the dwarves get short shrift, I thought I'd rather go to dinner with the dwarves than the elves; you'd have a lot more fun singing and drinking ale with them!
"As the plot unfolds, the children find themselves in very perilous situations but, as in Roald Dahl's books, awful things happen to children and you get those Dickensian, comic exaggerations, so I think you can have your cake and eat it; you can put the children in difficult places as long as you can lighten it with humour.
"In this book, the Countess is the evil person; she is beautiful, vain and incredibly cold-hearted. Believe me, after spending so much time writing about awful 17-year-olds for television, creating her was easy."