Kidman memory loss movie buoys author SJ Watson
Letting Hollywood loose on a best-selling novel is a risk for any author. If the film is panned, the most obvious dangers are alienating established fans and potentially putting off new readers.
Yet contemporary book-to-screen adaptations are coming thick and fast. The Fault in Our Stars, The 100-year-old Man who Climbed out of the Window and Disappeared and the forthcoming Gone Girl are just some examples.
The latest is memory loss thriller Before I Go To Sleep, the debut novel by Steven "SJ" Watson, which has sold more than four million copies and been published in more than 30 countries.
It's the story of Christine, a 47-year-old woman with a rare form of amnesia which causes her to lose all memory, even of the previous day's events, when she wakes up. Her condition is the result of a car accident 20 years before, or so she (and we) are told by her husband, Ben.
Each day, Christine wakes believing she's still in her 20s, and has to go through the trauma of acknowledging her true age and appearance. And Ben has to explain her life to her again and again.
But as the story unfolds, it becomes clear all is not what it seems, as Christine learns by way of the diary she discovers she is keeping and the help of the doctor she is secretly seeing to help restore her memory.
Nicole Kidman plays Christine, while Colin Firth plays Ben and Mark Strong is the doctor.
It would be easy to suspect part-time NHS audiologist Watson's motives were largely pecuniary when handing over the film rights to director Rowan Joffe. But, movies and money were the last thing on his mind, says Watson - preoccupied as he was with getting his book onto the shelves.
"I was totally daunted by it, it was so surreal.
"I wrote the book just hoping people would like it. Film had been mentioned by my agent even though people were careful not to raise my hopes. So, I was delighted it had elicited such a robust response."
Any doubts Watson may have had about a film were dispelled on meeting Joffe - the director seemed to know more about the book than Watson himself.
"He'd already done a huge amount of work. He was telling me all about his ideas and things I hadn't even noticed about the story and characters," says the author.
"He recognised it wasn't just a thriller but a real drama with the opportunity to play with the audience's expectations. The audience is in the same head space as Christine and subject to the same revelations she is and at the same time."
Nicole Kidman on playing Christine
The challenge was playing someone who doesn't know who they are or who they are married to. How do you play that and make it authentic and truthful?
And I love great twists and am drawn to psychological thrillers. But they are few and far between. Studios don't want to make them - they want to make films like Guardians of the Galaxy.
It's not left a lasting impression. I've played harrowing roles before and I've always been able to morph into a particular state of mind and then shed it.
It was refreshing to be less glamorous and more raw. I'm always looking for different things as I don't want to be pigeonholed. I was about 10 minutes in the make-up chair - a dream. I can't stand sitting there, that's why I've never done a special effects movie.
Colin Firth is lovely, committed and a brilliant actor, which is why it's great to see him doing something so different but it was also distressing - for both of us. We have the same humour and he's tall, so I get to look up to him!
As for the subject of memory, as you get older it gets foggier. Remembering scripts does get harder. Learning lines I notice I have to really work my brain and it now takes much longer, I used to be able to learn a page just by reading it once. My memory for numbers though is phenomenal.
If I couldn't learn lines any more I'd write, short stories and screenplays. I've always written, since I was a child. But publishing anything just doesn't interest me.
Watson deliberately didn't involve himself in the making of the movie.
"I decided early on that my job was to make sure the story was in the right people's hands and then to stand back," he says.
"If I started picking at things, like the colour of Christine's hair or the age of the cast, I could ruin everything. Unless they were going to do something I considered totally wrong, it needed to be Rowan's vision and project.
"The other thing was that I'd heard so many stories of authors who had had films made of their books and been disappointed. So, I thought, if it did turn out to be rubbish, I wouldn't have had anything to do with it. But if it were great I could take some of the credit."
With such a hands-off approach, it's lucky Watson is happy with the adaptation and casting, especially Kidman.
"My first thought was that she was a very versatile actor, having done so many roles so I thought yes, she can do this. I went out and rented all the movies with her that I could. The Others and Rabbit Hole stood out and I could just see her as Christine after that. She does dark thriller roles really well."
One stumbling block could have been Kidman's characteristically glamorous and youthful appearance, since Watson's Christine is unable to maintain either. But this has been dealt with well, says the author.
"A worry would be if she [Kidman} had insisted on looking beautifully made up with perfect hair and so on but that's not the case. The character in the book is older than Nicole, but I think it all works well. It would have been wrong to put Nicole in ageing prosthetics."
As for Firth and Strong, Watson says they were an inspired choice. Without giving too much away, suffice to say both play roles that go against type.
"I was excited about the casting. Firth in particular will be a shock to the audience. But he's very nuanced and he plays that role really well. I imagine he was pleased to have the opportunity to play a different kind of role and it's not as if he has to take jobs to pay the mortgage," says Watson.
Watson cites Fight Club as one of his favourite book to film adaptations. But he doesn't feel the current trend for remakes and adaptations is necessarily a good thing.
"If that is the case, it's a shame because there could be a really interesting screenplay out there that would not necessarily make a great novel," says Watson.
"If it's a sign of an industry that is becoming more risk-averse, in that it is less likely to take something that doesn't have a proven track record, that's a real shame too.
"And if turnover gets more speedy then people aren't going to get the chance to read the books."
But Watson himself is adamant he won't allow the movies to cloud his future vision.
"I've just written my second book and I told myself that if I started thinking: 'Will this make a good film', it would pile on more pressure and probably take any creativity away.
"You're on a hiding to nothing, you're coming at writing from an impure place. The story has to come first. Trying to insert things like car chases that would work on screen would make things messy.
"My job is as a novelist and if someone reads my work and thinks they want to put it on the big screen, that's great. But if they don't, that's great too."
Before I Go To Sleep is released across the UK on 5 September. SJ Watson's new novel Second Life will be published in February 2015.