Alex Pettyfer is quite a discovery, he really holds the screen playing Alex Rider doesn't he?
"If you look at the trailer, when the teacher says 'Alex Rider have you prepared something for us?' and he looks up and says 'yes sir', there is so much going on in that face at that little moment. It's the first moment in the film, I always used to say when we were on the set that the audience will love or hate it at that moment. That's when they'll decide if they're going to enjoy the film, when they first see the boy playing Alex Rider and the first thing he does.
He's a very nice boy, a wonderful actor, he has extraordinary looks and he's nice with it. I think what we have with him is something that is really unique; it was a one in a million chance that he got that role. I'm just so happy that he did."
Your villain has changed too hasn't he?
"The villain is Herod Sayle in the books, Darrius Sayle in the film. The reason for that is that Mickey Rourke entered the picture. Suddenly to have him be a small balding Lebanese businessman - which is what you get in the book - was ridiculous, so I completely reconsidered the part, called him Darrius, made him Californian, but kept the same motivation. The reason why he does what he does remains the same. It's basically inverted racism, he's a foreigner who's been badly treated by the British."
Your involvement presumably insulates the film adaptation from too much criticism from fans, doesn't it?
"Having agreed to be the screenwriter of it, I became the guardian of Alex's probity, of making it right."
Do you have ambitions to direct anytime soon?
"No. I have directed a television series in the past, and very quickly learnt that my talents do not extend to directing. It's very tempting, but as somebody who's been working writing film and TV and books for so long, part of me does say try it again and have another go. What's the point of continuing unless you're going to continue to challenge yourself and find new things to do? And scare yourself a little bit. So maybe.
I talk sometimes about projects, I've got a short film in my head that I might turn my hand to directing. But I don't think I have a huge career ahead of me as a director, especially having watched Geoff doing it on the set of Stormbreaker. I think I'm very much better locked in a dark room with my computer."