Stephen's dome story is based on a pre-Simpsons novel
Stephen King has a great way of dissociating himself with dodgy screen versions of his books.
"Adapting books means maximum deniability for me," says the literary legend. "If they make something good out of what I've done, like The Shawshank Redemption, then I say, 'That's based on my work!'
"If it's something like Firestarter, which wasn't particularly good, I can say, 'Well I didn't have anything to do with that'."
Luckily 65-year-old Stephen, who also wrote Misery, The Shining and just about every best-selling horror novel going in the last 40 years, has no such fears for the TV adaptation of Under The Dome. Especially with Steven Spielberg as executive producer.
Stephen started writing the novel in 1972, two years before Carrie, the first of his books to be published, was released, but he had "no money and no time" so the project fell by the wayside.
"I snatched time to write at the weekends and I couldn't do the research," he says.
However, on a flight to Melbourne, where he was heading for a motorcycle ride across the Outback, Stephen realised that he wanted to revisit his notes and, after some rejigging, Under The Dome was published in 2009.
The novel is set in a small New England town that is suddenly and inexplicably sealed off from the rest of the world by an enormous transparent dome. The inhabitants, who in the 13-part TV adaptation include Blue Valentine actor Mike Vogel as army veteran Dale 'Barbie' Barbara, Rachelle Lefevre as journalist Julia Shumway and Breaking Bad's Dean Norris as James 'Big Jim' Rennie, are left questioning what the barrier is, where it came from and if and when it will go away.
"I had this image of people on this row trying to talk to reporters and touch their loved ones' hands. They're so close, millimetres apart, but unable to touch and I thought, 'This is so cool, I have to do it'," says Stephen, whose novel The Body was immortalised in the 1986 Hollywood hit Stand By Me starring River Phoenix. "That's what moves me. I thought, 'This is going to be a blast, it's going to be fun'."
Deniability may be his watchword for bad adaptations, but he's not precious about how his original material is used. "It's easy to let go of my books because if you try and hold on and run everything, first of all things don't happen as easily," explains the father of three grown-up children.
"Second of all, you get ulcers. Besides, I'm a go-along guy. When I was a kid my mother used to say, 'Stephen if you'd been a girl, you'd always be pregnant', and there's some truth to that."
Despite his huge achievements, this grounded grandfather, who makes for an unlikely-looking millionaire with his dark, baggy T-shirt and a rucksack slung at his side, is not about to get cocky with predictions about the success of the series.
"I have no idea how far they'll go with it and what they'll do with it but one thing I've said is, 'Let's think all the time about how we're going to button this up'," he says.
"Because what guys like me do is run the store and there's always more supplies, and there can always be another story. If you like the story, maybe something else will come along."
Some viewers who like the story might be reminded of The Simpsons Movie, in which the fictional town of Springfield was ensconced in an invisible dome. Stephen is not one of them. "I was totally gobsmacked and blind-sided when people started to say, 'Oh The Simpsons already did this'," he says, laughing. "I figured to myself, 'I am so glad that I wrote my book beforehand, otherwise I would have been down'."
Not given to pomposity, Stephen, who has been married to his college sweetheart Tabitha since 1971, is forthright when it comes to discussing his own writing style.
"I am a situation guy," he says. "If I see a plot I kill it. The writer John Irving is a lovely man but the first thing he does when he writes a book is to write the last sentence. And I think to myself, 'This guy is totally out of his mind!'"
Likewise, he admits that he was always baffled by his mother's reading habits. "When I was a kid my mother used to read all these Agatha Christie novels and I'd see her at the back of the book and I'd say, 'Ma, what are you doing?' And she'd say, 'I wanted to know who did it so I can see how they lied their way out of it'. To me that defeats the whole purpose."
Under The Dome starts on Channel 5 on Monday.